Lua 5.05.0

138 files changed, 16112 insertions, 12226 deletions

diff --git a/COPYRIGHT b/COPYRIGHT
index eef88b05..fd3cdf9b 100644
--- a/COPYRIGHT
+++ b/COPYRIGHT
@@ -1,53 +1,33 @@
-Lua Copyright Notice
---------------------
+Lua License
+-----------
 
-Lua is free and non-proprietary.
-It can be used for both academic and commercial purposes at absolutely no cost.
-There are no royalties or GNU-like "copyleft" restrictions.
-Lua (probably) qualifies as Open Source software.
-Nevertheless, Lua is not in the public domain and TeCGraf keeps its copyright. 
+Lua is licensed under the terms of the MIT license reproduced below.
+This means that Lua is free software and can be used for both academic
+and commercial purposes at absolutely no cost.
 
-If you use Lua, please give us credit (a nice way to do this is to include a
-Lua logo in a web page for your product), but we would appreciate *not*
-receiving lengthy legal documents to sign.
-
-The legal details are below. 
+For details and rationale, see http://www.lua.org/license.html .
 
 ===============================================================================
 
-Copyright (C) 1994-2000 TeCGraf, PUC-Rio.  All rights reserved.
-
-Permission is hereby granted, without written agreement and without license
-or royalty fees, to use, copy, modify, translate, and distribute
-this software and its documentation (hereby called the "package")
-for any purpose, including commercial applications, subject to
-the following conditions:
-
- * The above copyright notice and this permission notice shall appear in all
-   copies or substantial portions of this package.
-
- * The origin of this package must not be misrepresented; you must not
-   claim that you wrote the original package. If you use this package in a
-   product, an acknowledgment in the product documentation would be greatly
-   appreciated (but it is not required).
-
- * Altered source versions must be plainly marked as such, and must not be
-   misrepresented as being the original package.
-   
-The authors specifically disclaim any warranties, including, but not limited
-to, the implied warranties of merchantability and fitness for a particular
-purpose.  The package provided hereunder is on an "as is" basis, and the
-authors have no obligation to provide maintenance, support, updates,
-enhancements, or modifications.  In no event shall TeCGraf, PUC-Rio, or the
-authors be held liable to any party for direct, indirect, special,
-incidental, or consequential damages arising out of the use of this package
-and its documentation.
-
-The Lua language and this implementation have been entirely designed and written
-by Waldemar Celes, Roberto Ierusalimschy, and Luiz Henrique de Figueiredo
-at TeCGraf, PUC-Rio in Brazil.
-
-This implementation contains no third-party code.
+Copyright (C) 2003 Tecgraf, PUC-Rio.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
 
 ===============================================================================
 
diff --git a/DIFFS b/DIFFS
deleted file mode 100644
index b7c86388..00000000
--- a/DIFFS
+++ /dev/null
@@ -1,97 +0,0 @@
-diff -r lua-4.0/include/lua.h lua/include/lua.h
-2c2
-< ** $Id: lua.h,v 1.79 2000/10/31 12:44:07 roberto Exp $
----
-> ** $Id: lua.h,v 1.79a 2000/10/31 12:44:07 roberto Exp $
-25c25
-< #define LUA_VERSION	"Lua 4.0"
----
-> #define LUA_VERSION	"Lua 4.0.1"
-diff -r lua-4.0/src/lapi.c lua/src/lapi.c
-2c2
-< ** $Id: lapi.c,v 1.110 2000/10/30 12:50:09 roberto Exp $
----
-> ** $Id: lapi.c,v 1.110a 2000/10/30 12:50:09 roberto Exp $
-488c488
-<   TString *ts = luaS_newudata(L, size, NULL);
----
->   TString *ts = luaS_newudata(L, (size==0) ? 1 : size, NULL);
-diff -r lua-4.0/src/ldo.c lua/src/ldo.c
-2c2
-< ** $Id: ldo.c,v 1.109 2000/10/30 12:38:50 roberto Exp $
----
-> ** $Id: ldo.c,v 1.109a 2000/10/30 12:38:50 roberto Exp $
-247c247,249
-<   luaC_checkGC(L);
----
->   /* before parsing, give a (good) chance to GC */
->   if (L->nblocks/8 >= L->GCthreshold/10)
->     luaC_collectgarbage(L);
-277,278c279,280
-<   filename = lua_tostring(L, -1);  /* filename = '@'..filename */
-<   lua_pop(L, 1);  /* OK: there is no GC during parser */
----
->   c = lua_gettop(L);
->   filename = lua_tostring(L, c);  /* filename = '@'..filename */
-280a283
->   lua_remove(L, c);  /* remove `filename' from the stack */
-diff -r lua-4.0/src/lgc.c lua/src/lgc.c
-2c2
-< ** $Id: lgc.c,v 1.72 2000/10/26 12:47:05 roberto Exp $
----
-> ** $Id: lgc.c,v 1.72+ 2000/10/26 12:47:05 roberto Exp $
-339c339
-< static void luaC_collectgarbage (lua_State *L) {
----
-> void luaC_collectgarbage (lua_State *L) {
-diff -r lua-4.0/src/lgc.h lua/src/lgc.h
-2c2
-< ** $Id: lgc.h,v 1.8 2000/10/02 14:47:43 roberto Exp $
----
-> ** $Id: lgc.h,v 1.9 2001/02/02 16:23:20 roberto Exp $
-14a15
-> void luaC_collectgarbage (lua_State *L);
-diff -r lua-4.0/src/lib/lbaselib.c lua/src/lib/lbaselib.c
-2c2
-< ** $Id: lbaselib.c,v 1.17 2000/11/06 13:45:18 roberto Exp $
----
-> ** $Id: lbaselib.c,v 1.17a 2000/11/06 13:45:18 roberto Exp $
-168c168
-<   lua_rawget(L, -2);
----
->   lua_rawget(L, 1);
-176c176
-<   lua_rawset(L, -3);
----
->   lua_rawset(L, 1);
-260c260
-<   if (*s == '\27')  /* binary files start with ESC... */
----
->   if (*s == '\33')  /* binary files start with ESC... */
-diff -r lua-4.0/src/lparser.c lua/src/lparser.c
-2c2
-< ** $Id: lparser.c,v 1.116 2000/10/27 11:39:52 roberto Exp $
----
-> ** $Id: lparser.c,v 1.117 2000/11/29 11:57:42 roberto Exp $
-1000c1000
-<   if (!block_follow(ls->t.token))
----
->   if (!block_follow(ls->t.token) && ls->t.token != ';')
-diff -r lua-4.0/src/lstring.c lua/src/lstring.c
-2c2
-< ** $Id: lstring.c,v 1.45 2000/10/30 17:49:19 roberto Exp $
----
-> ** $Id: lstring.c,v 1.45a 2000/10/30 17:49:19 roberto Exp $
-122c122
-<   ts->u.d.value = (udata == NULL) ? uts+1 : udata;
----
->   ts->u.d.value = (s > 0) ? uts+1 : udata;
-diff -r lua-4.0/src/lvm.c lua/src/lvm.c
-2c2
-< ** $Id: lvm.c,v 1.146 2000/10/26 12:47:05 roberto Exp $
----
-> ** $Id: lvm.c,v 1.146a 2000/10/26 12:47:05 roberto Exp $
-82c82
-<     luaD_lineHook(L, base-2, newline, linehook);
----
->     luaD_lineHook(L, base-1, newline, linehook);
diff --git a/HISTORY b/HISTORY
index 10b033ae..cf6e1c01 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,4 +1,52 @@
-This is Lua 4.0.
+This is Lua 5.0.
+
+* Changes from version 4.0 to 5.0
+  -------------------------------
+  Language:
+  + lexical scoping.
+  + Lua coroutines.
+  + standard libraries now packaged in tables.
+  + tags replaced by metatables and tag methods replaced by metamethods,
+    stored in metatables.
+  + proper tail calls.
+  + each function can have its own global table, which can be shared.
+  + new __newindex metamethod, called when we insert a new key into a table.
+  + new block comments: --[[ ... ]].
+  + new generic for.
+  + new weak tables.
+  + new boolean type.
+  + new syntax "local function".
+  + (f()) returns the first value returned by f.
+  + {f()} fills a table with all values returned by f.
+  + \n ignored in [[\n .
+  + fixed and-or priorities.
+  + more general syntax for function definition (e.g. function a.x.y:f()...end).
+  + more general syntax for function calls (e.g. (print or write)(9)).
+  + new functions (time/date, tmpfile, unpack, require, load*, etc.).
+  API:
+  + chunks are loaded by using lua_load; new luaL_loadfile and luaL_loadbuffer.
+  + introduced lightweight userdata, a simple "void*" without a metatable.
+  + new error handling protocol: the core no longer prints error messages;
+    all errors are reported to the caller on the stack.
+  + new lua_atpanic for host cleanup.
+  + new, signal-safe, hook scheme.
+  Implementation:
+  + new license: MIT.
+  + new, faster, register-based virtual machine.
+  + support for external multithreading and coroutines.
+  + new and consistent error message format.
+  + the core no longer needs "stdio.h" for anything (except for a single
+    use of sprintf to convert numbers to strings).
+  + lua.c now runs the environment variable LUA_INIT, if present. It can
+    be "@filename", to run a file, or the chunk itself.
+  + support for user extensions in lua.c.
+    sample implementation given for command line editing.
+  + new dynamic loading library, active by default on several platforms.
+  + safe garbage-collector metamethods.
+  + precompiled bytecodes checked for integrity (secure binary dostring).
+  + strings are fully aligned.
+  + position capture in string.find.
+  + read('*l') can read lines with embedded zeros.
 
 * Changes from version 3.2 to 4.0
   -------------------------------
@@ -18,7 +66,7 @@ This is Lua 4.0.
   + New API: fully re-entrant, simpler, and more efficient.
   + New debug API.
   Implementation:
-  + cleaner virtual machine -- at least 20% faster.
+  + faster than ever: cleaner virtual machine and new hashing algorithm.
   + non-recursive garbage-collector algorithm.
   + reduced memory usage for programs with many strings.
   + improved treatment for memory allocation errors.
diff --git a/INSTALL b/INSTALL
index e31eefad..748c6861 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,16 +1,18 @@
-This is Lua 4.0.
+This is Lua 5.0.
 
 * Installation
   ------------
   Building Lua on a Unix system should be very easy:
 
-	1. Edit "config" to suit your platform, if at all necessary.
+	1. Read "config" and edit it to suit your platform and needs.
+	   We strongly recommend that you enable support for dynamic loading,
+	   if your platform allows it.
 	2. Do "make".
 	3. If you want to install Lua in an "official" place in your system,
 	   then do "make install". The official place and the way to install
 	   files are defined in "config". You may have to be root to do this.
 
-  See below for instructions for Windows and Macintosh.
+  See below for instructions for Windows and other systems.
 
 * What you get
   ------------
@@ -20,7 +22,7 @@ This is Lua 4.0.
 	* include files in ./include.
   These are the only directories you need for development.
 
-  There man pages for lua and luac in both nroff and html, and a reference
+  There are man pages for lua and luac, in both nroff and html; a reference
   manual in html in ./doc, some sample code in ./test, and some useful stuff
   in ./etc. You don't need these directories for development.
 
@@ -35,38 +37,44 @@ This is Lua 4.0.
 * Shared libraries
   ----------------
   If you are running Linux, do "make so" after "make" succeeds.
-  This will create shared libraries in ./lib. It's probably better to
-  build shared libraries before "make install".
+  This will create shared libraries in ./lib.
+  To install those shared libraries in an official place, do "make soinstall".
 
   If you want the interpreter and the compiler to use shared libraries,
-  then do "make sobin" too.
+  then do "make sobin" too. You may want to do this before "make install".
 
-  You may need to include lib/ in the LD_LIBRAY_PATH environment variable
-  to link programs that use the shared libraries if you don't put them in
-  the "official" places with "make install".
+  If you only want the shared libraries, you may want to add -fPIC to MYCFLAGS
+  in "config". Also, you may need to run "ldconfig" as root.
+
+  You may need to include ./lib in the LD_LIBRARY_PATH environment variable
+  to link programs that use the shared libraries if you don't put them in the
+  official places with "make install". (You may need to use the full path.)
 
   Building shared libraries in other systems is similar but details differ;
   you may need to fix a few details in the top-level Makefile.
 
-* Installation on Windows or Macintosh
-  ------------------------------------
-  The instructions for building Lua on a Mac or Windows machine depend on
-  the particular compiler you are using.
-  The simplest way is to create a folder with all .c and .h files.
-  Then create projects for the core library, the standard library,
-  the interpreter, and the compiler, as follows:
+* Installation on Windows and other systems
+  -----------------------------------------------------
+  The instructions for building Lua on other systems machine depend on the
+  particular compiler you are using. The simplest way is to create a folder
+  with all .c and .h files, and then create projects for the core library,
+  the standard library, the interpreter, and the compiler, as follows:
 
-  core lib:	lapi.c lcode.c ldebug.c ldo.c lfunc.c lgc.c llex.c lmem.c
-		lobject.c lparser.c lstate.c lstring.c ltable.c ltests.c
-		ltm.c lundump.c lvm.c lzio.c
+  core lib:	lapi.c lcode.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c
+                lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c
+		ltable.c ltests.c ltm.c lundump.c lvm.c lzio.c
 
-  standard lib:	lauxlib.c lbaselib.c ldblib.c liolib.c lmathlib.c lstrlib.c
+  standard lib:	lauxlib.c lbaselib.c ldblib.c liolib.c lmathlib.c ltablib.c
+                lstrlib.c loadlib.c
 
   interpreter:	core lib, standard lib, lua.c
 
-  compiler:	core lib, dump.c luac.c opt.c print.c stubs.c
+  compiler:	core lib, standard lib, luac.c print.c
+		and also lopcodes.c (with LUA_OPNAMES defined) from core.
 
   Of course, to use Lua as a library, you'll have to know how to create
   and use libraries with your compiler.
 
+  Also, read "config" to see what can be customized at compilation time.
+
 (end of INSTALL)
diff --git a/MANIFEST b/MANIFEST
index d7dfbc54..e26c9de2 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -1,133 +1,130 @@
-MANIFEST contents of Lua 4.0 distribution on Mon Nov  6 19:15:16 EDT 2000
-lua
-lua/COPYRIGHT
-lua/HISTORY
-lua/INSTALL
-lua/MANIFEST
-lua/Makefile
-lua/README
-lua/bin
-lua/config
-lua/doc
-lua/doc/idx.html
-lua/doc/index.html
-lua/doc/logo.gif
-lua/doc/lua.1
-lua/doc/lua.html
-lua/doc/luac.1
-lua/doc/luac.html
-lua/doc/manual.html
-lua/doc/readme.html
-lua/etc
-lua/etc/Makefile
-lua/etc/README
-lua/etc/bin2c.c
-lua/etc/def.lua
-lua/etc/lua.ico
-lua/etc/lua.magic
-lua/etc/lua.xpm
-lua/etc/min.c
-lua/etc/setfallback.lua
-lua/etc/stdcall.lua
-lua/etc/trace.c
-lua/include
-lua/include/Makefile
-lua/include/lauxlib.h
-lua/include/lua.h
-lua/include/luadebug.h
-lua/include/lualib.h
-lua/lib
-lua/src
-lua/src/Makefile
-lua/src/lapi.c
-lua/src/lapi.h
-lua/src/lcode.c
-lua/src/lcode.h
-lua/src/ldebug.c
-lua/src/ldebug.h
-lua/src/ldo.c
-lua/src/ldo.h
-lua/src/lfunc.c
-lua/src/lfunc.h
-lua/src/lgc.c
-lua/src/lgc.h
-lua/src/lib
-lua/src/lib/Makefile
-lua/src/lib/README
-lua/src/lib/lauxlib.c
-lua/src/lib/lbaselib.c
-lua/src/lib/ldblib.c
-lua/src/lib/liolib.c
-lua/src/lib/lmathlib.c
-lua/src/lib/lstrlib.c
-lua/src/llex.c
-lua/src/llex.h
-lua/src/llimits.h
-lua/src/lmem.c
-lua/src/lmem.h
-lua/src/lobject.c
-lua/src/lobject.h
-lua/src/lopcodes.h
-lua/src/lparser.c
-lua/src/lparser.h
-lua/src/lstate.c
-lua/src/lstate.h
-lua/src/lstring.c
-lua/src/lstring.h
-lua/src/ltable.c
-lua/src/ltable.h
-lua/src/ltests.c
-lua/src/ltm.c
-lua/src/ltm.h
-lua/src/lua
-lua/src/lua/Makefile
-lua/src/lua/README
-lua/src/lua/lua.c
-lua/src/luac
-lua/src/luac/Makefile
-lua/src/luac/README
-lua/src/luac/dump.c
-lua/src/luac/luac.c
-lua/src/luac/luac.h
-lua/src/luac/opt.c
-lua/src/luac/print.c
-lua/src/luac/print.h
-lua/src/luac/stubs.c
-lua/src/lundump.c
-lua/src/lundump.h
-lua/src/lvm.c
-lua/src/lvm.h
-lua/src/lzio.c
-lua/src/lzio.h
-lua/test
-lua/test/README
-lua/test/bisect.lua
-lua/test/cf-for.lua
-lua/test/cf.lua
-lua/test/examples
-lua/test/examples/ps
-lua/test/examples/ps/hilbert.lua
-lua/test/examples/ps/ps.lua
-lua/test/examples/www
-lua/test/examples/www/README
-lua/test/examples/www/db.lua
-lua/test/examples/www/staff.lua
-lua/test/examples/www/template.html
-lua/test/factorial.lua
-lua/test/fib.lua
-lua/test/globals.lua
-lua/test/hello.lua
-lua/test/life.lua
-lua/test/lisp.lua
-lua/test/lua
-lua/test/luac
-lua/test/old.lua
-lua/test/qp.lua
-lua/test/save.lua
-lua/test/sort.lua
-lua/test/table.lua
-lua/test/trace-calls.lua
-lua/test/trace-globals.lua
-lua/test/undefined.lua
-lua/test/webform.lua
+MANIFEST contents of Lua 5.0 distribution on Fri Apr 11 11:01:08 BRT 2003
+lua-5.0
+lua-5.0/COPYRIGHT
+lua-5.0/HISTORY
+lua-5.0/INSTALL
+lua-5.0/MANIFEST
+lua-5.0/Makefile
+lua-5.0/README
+lua-5.0/bin
+lua-5.0/build
+lua-5.0/config
+lua-5.0/configure
+lua-5.0/doc
+lua-5.0/doc/logo.gif
+lua-5.0/doc/lua.1
+lua-5.0/doc/lua.html
+lua-5.0/doc/luac.1
+lua-5.0/doc/luac.html
+lua-5.0/doc/manual.html
+lua-5.0/doc/readme.html
+lua-5.0/etc
+lua-5.0/etc/.exrc
+lua-5.0/etc/Makefile
+lua-5.0/etc/README
+lua-5.0/etc/bin2c.c
+lua-5.0/etc/compat.lua
+lua-5.0/etc/doall.lua
+lua-5.0/etc/lua.ico
+lua-5.0/etc/lua.magic
+lua-5.0/etc/lua.xpm
+lua-5.0/etc/luser_number.h
+lua-5.0/etc/luser_tests.h
+lua-5.0/etc/min.c
+lua-5.0/etc/noparser.c
+lua-5.0/etc/saconfig.c
+lua-5.0/etc/trace.c
+lua-5.0/include
+lua-5.0/include/Makefile
+lua-5.0/include/lauxlib.h
+lua-5.0/include/lua.h
+lua-5.0/include/lualib.h
+lua-5.0/lib
+lua-5.0/src
+lua-5.0/src/Makefile
+lua-5.0/src/README
+lua-5.0/src/lapi.c
+lua-5.0/src/lapi.h
+lua-5.0/src/lcode.c
+lua-5.0/src/lcode.h
+lua-5.0/src/ldebug.c
+lua-5.0/src/ldebug.h
+lua-5.0/src/ldo.c
+lua-5.0/src/ldo.h
+lua-5.0/src/ldump.c
+lua-5.0/src/lfunc.c
+lua-5.0/src/lfunc.h
+lua-5.0/src/lgc.c
+lua-5.0/src/lgc.h
+lua-5.0/src/lib
+lua-5.0/src/lib/Makefile
+lua-5.0/src/lib/README
+lua-5.0/src/lib/lauxlib.c
+lua-5.0/src/lib/lbaselib.c
+lua-5.0/src/lib/ldblib.c
+lua-5.0/src/lib/liolib.c
+lua-5.0/src/lib/lmathlib.c
+lua-5.0/src/lib/loadlib.c
+lua-5.0/src/lib/lstrlib.c
+lua-5.0/src/lib/ltablib.c
+lua-5.0/src/llex.c
+lua-5.0/src/llex.h
+lua-5.0/src/llimits.h
+lua-5.0/src/lmem.c
+lua-5.0/src/lmem.h
+lua-5.0/src/lobject.c
+lua-5.0/src/lobject.h
+lua-5.0/src/lopcodes.c
+lua-5.0/src/lopcodes.h
+lua-5.0/src/lparser.c
+lua-5.0/src/lparser.h
+lua-5.0/src/lstate.c
+lua-5.0/src/lstate.h
+lua-5.0/src/lstring.c
+lua-5.0/src/lstring.h
+lua-5.0/src/ltable.c
+lua-5.0/src/ltable.h
+lua-5.0/src/ltests.c
+lua-5.0/src/ltm.c
+lua-5.0/src/ltm.h
+lua-5.0/src/lua
+lua-5.0/src/lua/Makefile
+lua-5.0/src/lua/README
+lua-5.0/src/lua/lua.c
+lua-5.0/src/luac
+lua-5.0/src/luac/Makefile
+lua-5.0/src/luac/README
+lua-5.0/src/luac/luac.c
+lua-5.0/src/luac/print.c
+lua-5.0/src/lundump.c
+lua-5.0/src/lundump.h
+lua-5.0/src/lvm.c
+lua-5.0/src/lvm.h
+lua-5.0/src/lzio.c
+lua-5.0/src/lzio.h
+lua-5.0/test
+lua-5.0/test/README
+lua-5.0/test/bisect.lua
+lua-5.0/test/cf.lua
+lua-5.0/test/compat.lua
+lua-5.0/test/echo.lua
+lua-5.0/test/env.lua
+lua-5.0/test/factorial.lua
+lua-5.0/test/fib.lua
+lua-5.0/test/fibfor.lua
+lua-5.0/test/globals.lua
+lua-5.0/test/hello.lua
+lua-5.0/test/life.lua
+lua-5.0/test/lua
+lua-5.0/test/luac
+lua-5.0/test/luac.lua
+lua-5.0/test/printf.lua
+lua-5.0/test/readonly.lua
+lua-5.0/test/sieve.lua
+lua-5.0/test/sort.lua
+lua-5.0/test/table.lua
+lua-5.0/test/trace-calls.lua
+lua-5.0/test/trace-globals.lua
+lua-5.0/test/undefined.lua
+lua-5.0/test/xd.lua
 END OF MANIFEST
diff --git a/Makefile b/Makefile
index adf018f2..007b72d0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,41 +1,99 @@
 # makefile for Lua hierarchy
 # see INSTALL for installation instructions
-# see file "config" for customization instructions
+# see config for customization instructions
 
 LUA= .
 
 include $(LUA)/config
 
-# primary targets (only "all" and "clean" are useful after distribution)
-all clean co klean:
+# primary targets ("co" and "klean" are used for making the distribution)
+all clean co klean:	dirs
 	cd include; $(MAKE) $@
 	cd src; $(MAKE) $@
-	cd src/luac; $(MAKE) $@
 	cd src/lib; $(MAKE) $@
+	cd src/luac; $(MAKE) $@
 	cd src/lua; $(MAKE) $@
 
+# in case they were not created during unpacking
+dirs:	bin lib
+
+bin lib:
+	mkdir -p $@
+
+# simple test to see Lua working
+test:	all
+	bin/lua test/hello.lua
+
 # remove debug information from binaries
 strip:
-	strip bin/lua bin/luac
+	$(STRIP) bin/*
 
 # official installation
 install: all strip
 	mkdir -p $(INSTALL_BIN) $(INSTALL_INC) $(INSTALL_LIB) $(INSTALL_MAN)
 	$(INSTALL_EXEC) bin/* $(INSTALL_BIN)
 	$(INSTALL_DATA) include/*.h $(INSTALL_INC)
-	$(INSTALL_DATA) lib/lib* $(INSTALL_LIB)
+	$(INSTALL_DATA) lib/*.a $(INSTALL_LIB)
 	$(INSTALL_DATA) doc/*.1 $(INSTALL_MAN)
 
 # shared libraries (for Linux)
 so:
 	ld -o lib/liblua.so.$V -shared src/*.o
 	ld -o lib/liblualib.so.$V -shared src/lib/*.o
-	cd lib; ln -s liblua.so.$V liblua.so; ln -s liblualib.so.$V liblualib.so
+	cd lib; ln -fs liblua.so.$V liblua.so; ln -fs liblualib.so.$V liblualib.so
 
 # binaries using shared libraries
 sobin:
-	rm -f bin/lua bin/luac
+	rm -f bin/*
 	cd src/lua; $(MAKE)
 	cd src/luac; $(MAKE)
 
+# install shared libraries
+soinstall:
+	$(INSTALL_EXEC) lib/*.so.* $(INSTALL_LIB)
+	cd $(INSTALL_LIB); ln -fs liblua.so.$V liblua.so; ln -fs liblualib.so.$V liblualib.so
+
+# clean shared libraries
+soclean:
+	rm -f lib/*.so* bin/*
+
+# echo config parameters
+echo:
+	@echo ""
+	@echo "These are the parameters currently set in $(LUA)/config to build Lua $V:"
+	@echo ""
+	@echo "LOADLIB = $(LOADLIB)"
+	@echo "DLLIB = $(DLLIB)"
+	@echo "NUMBER = $(NUMBER)"
+	@echo "POPEN = $(POPEN)"
+	@echo "TMPNAM = $(TMPNAM)"
+	@echo "DEGREES = $(DEGREES)"
+	@echo "USERCONF = $(USERCONF)"
+	@echo "CC = $(CC)"
+	@echo "WARN = $(WARN)"
+	@echo "MYCFLAGS = $(MYCFLAGS)"
+	@echo "MYLDFLAGS = $(MYLDFLAGS)"
+	@echo "EXTRA_LIBS = $(EXTRA_LIBS)"
+	@echo "AR = $(AR)"
+	@echo "RANLIB = $(RANLIB)"
+	@echo "STRIP = $(STRIP)"
+	@echo "INSTALL_ROOT = $(INSTALL_ROOT)"
+	@echo "INSTALL_BIN = $(INSTALL_BIN)"
+	@echo "INSTALL_INC = $(INSTALL_INC)"
+	@echo "INSTALL_LIB = $(INSTALL_LIB)"
+	@echo "INSTALL_MAN = $(INSTALL_MAN)"
+	@echo "INSTALL_EXEC = $(INSTALL_EXEC)"
+	@echo "INSTALL_DATA = $(INSTALL_DATA)"
+	@echo ""
+	@echo "Edit $(LUA)/config if needed to suit your platform and then run make."
+	@echo ""
+
+# turn config into Lua code
+# uncomment the last sed expression if you want nil instead of empty strings
+lecho:
+	@echo "-- $(LUA)/config for Lua $V"
+	@echo "VERSION = '$(V)'"
+	@make echo | grep = | sed -e 's/= /= "/' -e 's/$$/"/' #-e 's/""/nil/'
+	@echo "-- EOF"
+
 # (end of Makefile)
diff --git a/README b/README
index 81f767ae..4aaaba52 100644
--- a/README
+++ b/README
@@ -1,72 +1,44 @@
-This is Lua 4.0.
-See HISTORY for a summary of changes since the last version.
+This is Lua 5.0.
+See HISTORY for a summary of changes since the last released version.
 
 * What is Lua?
   ------------
   Lua is a powerful, light-weight programming language designed for extending
   applications. Lua is also frequently used as a general-purpose, stand-alone
-  language.
+  language. Lua is free software.
 
-  Lua combines simple procedural syntax (similar to Pascal) with powerful
-  data description constructs based on associative arrays and extensible
-  semantics. Lua is dynamically typed, interpreted from bytecodes, and has
-  automatic memory management, making it ideal for configuration, scripting,
-  and rapid prototyping.
-
-  Lua is a language engine that you can embed into your application.
-  This means that, besides syntax and semantics, Lua has an API that
-  allows the application to exchange data with Lua programs and also to
-  extend Lua with C functions. In this sense, Lua can be regarded as a
-  language framework for building domain-specific languages.
-
-  Lua is implemented as a small library of C functions, written in ANSI C,
-  and compiles unmodified in all known platforms. The implementation goals
-  are simplicity, efficiency, portability, and low embedding cost.
-  The result is a fast language engine with small footprint, making it
-  ideal in embedded systems too.
-
-  Lua was awarded the first prize (technological category) in the
-  Second Compaq Award for Research and Development in Computer Science in 1997.
-  This award was a joint venture of Compaq Computer in Brazil, the Brazilian
-  Ministry of Science and Technology, and the Brazilian Academy of Sciences.
+  For complete information, visit Lua's web site at http://www.lua.org/ .
+  For an executive summary, see http://www.lua.org/about.html .
 
   Lua has been used in many different projects around the world.
-  For a short list, see http://www.tecgraf.puc-rio.br/lua/uses.html .
+  For a short list, see http://www.lua.org/uses.html .
 
 * Availability
   ------------
-  Lua is freely available for both academic and commercial purposes and
-  can be downloaded from the sites below. See COPYRIGHT for details.
-
-    Home page:  http://www.tecgraf.puc-rio.br/lua/
-                http://csg.uwaterloo.ca/~lhf/lua/
-    In Brazil:  ftp://ftp.tecgraf.puc-rio.br/pub/lua/
-    In Canada:  ftp://csg.uwaterloo.ca/pub/lhf/lua/
-    In the US:  ftp://ftp.freesoftware.com/pub/languages/lua/
-    In Germany: ftp://ftp.uni-trier.de/pub/languages/lua/
-    In Germany: ftp://ftp.gwdg.de/pub/languages/lua/
-    In Greece:  ftp://ftp.ntua.gr/pub/lang/lua/
-    In Japan:   ftp://ftp.u-aizu.ac.jp/pub/lang/lua/
-    In Denmark: ftp://ftp.ucore.com/lua/dist
+  Lua is freely available for both academic and commercial purposes.
+  See COPYRIGHT and http://www.lua.org/license.html for details.
+  Lua can be downloaded from its official site http://www.lua.org/ and
+  several other sites aroung the world. For a complete list of mirror sites,
+  see http://www.lua.org/mirrors.html .
 
 * Installation
   ------------
-  See INSTALL.
+  Lua is implemented in pure ANSI C, and compiles unmodified in all known
+  platforms that have an ANSI C compiler. Under Unix, simply typing "make"
+  should work. See INSTALL for detailed instructions.
 
 * Contacting the authors
   ----------------------
-  Lua was designed and implemented by Waldemar Celes, Roberto Ierusalimschy
-  and Luiz Henrique de Figueiredo.
-  They can be contacted by email at lua@tecgraf.puc-rio.br. 
-
   Send your comments, questions, and bug reports to lua@tecgraf.puc-rio.br.
+  For more information about the authors, see http://www.lua.org/authors.html .
   For reporting bugs, try also the mailing list: lua-l@tecgraf.puc-rio.br.
   For more information about this list, including instructions on how to
-  subscribe, see http://www.tecgraf.puc-rio.br/lua/lua-l.html .
+  subscribe and access the archives, see http://www.lua.org/lua-l.html .
 
-  Lua is developed at TeCGraf, the Computer Graphics Technology Group
-  of PUC-Rio (the Pontifical Catholic University of Rio de Janeiro in Brazil). 
-  TeCGraf is a laboratory of the Department of Computer Science.
-  Dozens of industrial products developed by TeCGraf use Lua.
+* Origin
+  ------
+  Lua is developed at Tecgraf, the Computer Graphics Technology Group
+  of PUC-Rio (the Pontifical Catholic University of Rio de Janeiro in Brazil).
+  Tecgraf is a laboratory of the Department of Computer Science.
 
 (end of README)
diff --git a/UPDATE b/UPDATE
deleted file mode 100644
index 1be0709d..00000000
--- a/UPDATE
+++ /dev/null
@@ -1,19 +0,0 @@
-This is an update of Lua 4.0 that includes the following bug fixes and
-improvements:
-
-lua/src/lapi.c
-lua/src/lstring.c
-	Fixed a bug in lua_pushuserdata(L, NULL)
-lua/src/ldo.c
-lua/src/lgc.c
-lua/src/lgc.h
-	Give a good chance for GC before parsing
-lua/src/lparser.c
-	Fixed a bug (did not accept `;' after a `return')
-lua/src/lvm.c
-	Fixed a bug (linehook off by 1)
-lua/src/lib/lbaselib.c
-	Fixed a bug in rawget and rawset (seg. fault if given extra arguments)
-	Fixed a bug in dostring (identification of precompiled chunks)
-
-To use simply open this tarball over the original Lua 4.0 source.
diff --git a/build b/build
new file mode 100755
index 00000000..6faed371
--- /dev/null
+++ b/build
@@ -0,0 +1,33 @@
+# If you don't want to use make, run this script.
+# But make sure you read config to see what can be customized.
+
+
+# Easiest way to build bin/lua:
+# cc -O2 -o bin/lua -Iinclude -Isrc src/*.c src/lib/*.c src/lua/*.c -lm -ldl
+
+
+# Easiest way to build Lua libraries and executables:
+echo -n 'building core library... '
+cd src
+cc -O2 -c -I../include *.c
+ar rc ../lib/liblua.a *.o
+rm -f *.o
+
+echo -n 'standard library... '
+cd lib
+cc -O2 -c -I../../include *.c
+ar rc ../../lib/liblualib.a *.o
+rm -f *.o
+
+echo -n 'lua... '
+cd ../lua
+cc -O2 -o ../../bin/lua -I../../include *.c ../../lib/*.a -lm -ldl
+
+echo -n 'luac... '
+cd ../luac
+cc -O2 -o ../../bin/luac -I../../include -I.. *.c -DLUA_OPNAMES ../lopcodes.c ../../lib/*.a
+
+echo 'done'
+
+cd ../..
+bin/lua test/hello.lua
diff --git a/config b/config
index 6a271eaf..34c77ea3 100644
--- a/config
+++ b/config
@@ -1,100 +1,178 @@
-# configuration file for making Lua
+# configuration file for making Lua 5.0
 # see INSTALL for installation instructions
 
-# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT =======================
+# These are default values. Skip this section and see the explanations below.
+
+LOADLIB=
+DLLIB=
+NUMBER=
+POPEN=
+TMPNAM=
+DEGREES=
+USERCONF=
 
-# ------------------------------------------------------------------ Lua
+# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT =======================
 
-# Lua uses double for numbers. To change this, uncomment one of the lines below.
-#NUMBER= -DLUA_NUM_TYPE=double
-#NUMBER= -DLUA_NUM_TYPE=float
-#NUMBER= -DLUA_NUM_TYPE=long
-# Optionally, you may also want change how numbers are converted to strings,
-# and vice-versa. Look for LUA_NUMBER in llimits.h and in the rest of the code.
+# --------------------------------------------------------------- Lua libraries
+
+# Support for dynamically loading C libraries for Lua is a very important
+# feature, which we strongly recommend be enabled. By default, this support is
+# enabled on Windows systems (see below) but disabled on other systems because
+# it relies on system-dependent code that is not part of ANSI C. For more
+# information on dynamic loading, read the comments in src/lib/liolib.c .
+#
+# To enable support for dynamic loading on Unix systems that support the dlfcn
+# interface (e.g., Linux, Solaris, IRIX, BSD, AIX, HPUX, and probably others),
+# uncomment the next two lines.
+#
+#LOADLIB= -DUSE_DLOPEN=1
+#DLLIB= -ldl
+#
+# In Linux with gcc, you should also uncomment the next definition for
+# MYLDFLAGS, which passes -E (= -export-dynamic) to the linker. This option
+# allows dynamic libraries to link back to the `lua' program, so that they do
+# not need the Lua libraries. (Other systems may have an equivalent facility.)
+#
+#MYLDFLAGS= -Wl,-E
+#
+# On Windows systems. support for dynamic loading is enabled by default.
+# To disable this support, uncomment the next line.
+#
+#LOADLIB= -DUSE_DLL=0
+
+# The Lua IO library (src/lib/liolib.c) has support for pipes using popen and
+# pclose. This support is enabled by default on POSIX systems.
+# If your system is not POSIX but has popen and pclose, define USE_POPEN=1.
+# If you don't want to support pipes, define USE_POPEN=0.
+#
+#POPEN= -DUSE_POPEN=1
+#POPEN= -DUSE_POPEN=0
+#
+# The form below will probably work in (some) Windows systems.
+#
+#POPEN= -DUSE_POPEN=1 -Dpopen=_popen -Dpclose=_pclose
+
+# The Lua OS library (src/lib/liolib.c) exports an interface to the C function
+# tmpnam, which gcc now thinks is `dangerous'. So, support for tmpnam is
+# disabled by default when compiling with gcc.
+# If you still want to use tmpnam, define USE_TMPNAME=1. If you don't want to
+# use tmpnam even if you're not compiling with gcc, define USE_TMPNAME=0.
+#
+#TMPNAM= -DUSE_TMPNAME=1
+#TMPNAM= -DUSE_TMPNAME=0
+
+# The Lua math library (src/lib/lmathlib.c) now operates in radians, unlike
+# previous versions of Lua, which used degrees. To use degrees instead of
+# radians, define USE_DEGREES.
+#
+#DEGREES= -DUSE_DEGREES
+
+# ------------------------------------------------------------------ Lua core
+
+# Lua uses double for numbers. To change this, uncomment and edit the following
+# line, changing USE_XXX to one of USE_DOUBLE, USE_FLOAT, USE_LONG, USE_INT.
+#
+#NUMBER= -DLUA_USER_H='"../etc/luser_number.h"' -DUSE_XXX
+
+# When compiling Lua with gcc on a Pentium machine, using a fast rounding
+# method for the conversion of doubles to ints can give around 20% speed
+# improvement. To use this rounding method, uncomment the following line.
+#NUMBER= -DLUA_USER_H='"../etc/luser_number.h"' -DUSE_FASTROUND
+
+# For partial compatibility with old upvalue syntax, define LUA_COMPATUPSYNTAX.
+# For partial compatibility with old upvalue behavior in C functions, define
+# LUA_COMPATUPVALUES. Add these definitions to MYCFLAGS.
+#
+# -DLUA_COMPATUPSYNTAX -DLUA_COMPATUPVALUES
+
+# ------------------------------------------------------------- Lua interpreter
 
-# If you want support for pipes, uncomment the following line.
-# You need popen in your C library.
-#POPEN= -DPOPEN
+# The stand-alone Lua interpreter needs the math functions, which are usually
+# in libm.a (-lm).  If your C library already includes the math functions,
+# or if you are using a modified interpreter that does not need them,
+# then comment the following line or add the appropriates libraries.
+#
+EXTRA_LIBS= -lm
 
-# If you need compatibility with previous versions, edit and uncomment the
-# definition of COMPAT below.
-# Use -DLUA_COMPAT_READPATTERN if you need complex read patterns.
-# Use -DLUA_COMPAT_ARGRET if you need the old semantics that used only the
-# first value returned by a function when it is called as the last parameter.
-# Use -DLUA_DEPRECATEDFUNCS if you need the obsolete functions in the standard 
-# Lua library (not recommended).
-#COMPAT= -DLUA_COMPAT_READPATTERN -DLUA_COMPAT_ARGRET -DLUA_DEPRECATEDFUNCS
+# If you want to customize the stand-alone Lua interpreter, uncomment and
+# edit the following two lines; also edit etc/saconfig.c to suit your needs.
+# -DUSE_READLINE adds line editing and history to the interpreter. You need
+# to add -lreadline (and perhaps also -lhistory and -lcurses or -lncurses)
+# to EXTRA_LIBS.
+#
+#USERCONF=-DLUA_USERCONFIG='"$(LUA)/etc/saconfig.c"' -DUSE_READLINE
+#EXTRA_LIBS= -lm -ldl -lreadline # -lhistory -lcurses -lncurses
 
 # ------------------------------------------------------------------ C compiler
 
-# You need an ANSI C compiler. gcc is a popular one.
+# You need an ANSI C compiler. gcc is a popular one. We do not use -ansi in
+# WARN because it disables POSIX features used in the libraries.
+#
 CC= gcc
-WARN= -ansi -pedantic -Wall
-
-# On IRIX, cc is a good ANSI compiler.
-#CC= cc
-#WARN= -ansi -fullwarn
-
-# On Solaris, cc is optional. You may have to add -Dsparc if you use -Xc.
-#CC= cc
-#WARN= -Xc # -Dsparc
-
-# ------------------------------------------------------------------ C library
+WARN= -Wall
 
-# If your C library is not POSIX compliant, comment the following line.
-POSIX= -D_POSIX_SOURCE
+# ------------------------------------------------------------------ C options
 
-# If your C library does not have the newer ANSI functions strerror, strcoll,
-# and locale support, uncomment the following line. SunOs 4.1.x is one example.
-#OLD_ANSI= -DOLD_ANSI
+# Write here any options you may need for your C compiler.
+# If you are using gcc, -O3 will get you a faster but larger code. You can
+# also add -fomit-frame-pointer to get even faster code at the cost of losing
+# debug information. If you only want the shared libraries, you may want to
+# add -fPIC to MYCFLAGS.
+#
+MYCFLAGS= -O2
+#MYCFLAGS= -O3 -fomit-frame-pointer # -fPIC
 
-# In SunOs 4.1.x, standard headers in /usr/include are not ANSI,
-# so uncomment the following line to avoid prototypes warnings.
-#EXTRA_INCS= -I/usr/5include
-
-# The stand-alone Lua interpreter needs the math functions, which are usually
-# in libm.a (-lm).  If your C library already includes the math functions,
-# or if you are using a modified interpreter that does not need them,
-# then comment the following line.
-EXTRA_LIBS= -lm
+# Write here any options you may need for your C linker.
+#MYLDFLAGS=
 
 # ------------------------------------------------------------------ librarian
 
 # This should work in all Unix systems.
+#
 AR= ar rcu
 
 # If your system doesn't have (or need) ranlib, use RANLIB=true.
 # On some systems, "ar s" does what ranlib would do.
+#
 RANLIB= ranlib
 #RANLIB= ar s
 #RANLIB= true
 
+# ------------------------------------------------------------------ stripper
+
+# This should work in all Unix systems, but you may want to add options.
+#
+STRIP= strip
+
 # ------------------------------------------------------------------ install
 
 # Locations for "make install". You may need to be root do "make install".
+#
 INSTALL_ROOT= /usr/local
 INSTALL_BIN= $(INSTALL_ROOT)/bin
 INSTALL_INC= $(INSTALL_ROOT)/include
 INSTALL_LIB= $(INSTALL_ROOT)/lib
 INSTALL_MAN= $(INSTALL_ROOT)/man/man1
 
-# You might prefer to use "install" if you have it.
+# You may prefer to use "install" instead of "cp" if you have it.
+# If you use "install", you may also want to change the permissions after -m.
+#
 INSTALL_EXEC= cp
 INSTALL_DATA= cp
 #INSTALL_EXEC= install -m 0755
 #INSTALL_DATA= install -m 0644
 
-# == END OF USER SETTINGS. DO NOT CHANGE ANYTHING BELOW THIS LINE =============
+# == END OF USER SETTINGS. NO NEED TO CHANGE ANYTHING BELOW THIS LINE =========
+
+V=5.0
 
 BIN= $(LUA)/bin
 INC= $(LUA)/include
 LIB= $(LUA)/lib
 
 INCS= -I$(INC) $(EXTRA_INCS)
-DEFS= $(COMPAT) $(NUMBER) $(OLD_ANSI) $(EXTRA_DEFS)
-
-CFLAGS= -O2 $(WARN) $(INCS) $(DEFS)
+DEFS= $(NUMBER) $(EXTRA_DEFS)
 
-V=4.0
+CFLAGS= $(MYCFLAGS) $(WARN) $(INCS) $(DEFS)
 
 # (end of config)
diff --git a/configure b/configure
new file mode 100755
index 00000000..0aa89712
--- /dev/null
+++ b/configure
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+# Lua does not use GNU autoconf; just edit ./config if needed to suit your
+# platform and then run make.
+
+# This shows the parameters currently set in ./config:
+make echo
+
+# If you want config as a Lua program, run "make lecho".
diff --git a/doc/idx.html b/doc/idx.html
deleted file mode 100644
index 74693a56..00000000
--- a/doc/idx.html
+++ /dev/null
@@ -1,411 +0,0 @@
-<HTML>
-<HEAD>
-<TITLE>Lua 4.0 Reference Manual - Word Index</TITLE>
-</HEAD>
-
-<BODY BGCOLOR="#FFFFFF">
-
-<HR>
-<H1>
-<IMG SRC="logo.gif" ALT="Lua" ALIGN="bottom">
-<A HREF="index.html">Reference manual</A>
-- word index
-</H1>
-
-<A HREF="manual.html#.."><TT>..</TT></A><BR>
-<A HREF="manual.html#_ALERT"><TT>_ALERT</TT></A><BR>
-<A HREF="manual.html#_ERRORMESSAGE"><TT>_ERRORMESSAGE</TT></A><BR>
-<A HREF="manual.html#_INPUT"><TT>_INPUT</TT></A><BR>
-<A HREF="manual.html#_OUTPUT"><TT>_OUTPUT</TT></A><BR>
-<A HREF="manual.html#_PROMPT"><TT>_PROMPT</TT></A><BR>
-<A HREF="manual.html#_STDERR"><TT>_STDERR</TT></A><BR>
-<A HREF="manual.html#_STDIN"><TT>_STDIN</TT></A><BR>
-<A HREF="manual.html#_STDOUT"><TT>_STDOUT</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#abs"><TT>abs</TT></A><BR>
-<A HREF="manual.html#acceptable index">acceptable index</A><BR>
-<A HREF="manual.html#acos"><TT>acos</TT></A><BR>
-<A HREF="manual.html#add event">``add'' event</A><BR>
-<A HREF="manual.html#Adjustment">adjustment</A><BR>
-<A HREF="manual.html#alert"><TT>alert</TT></A><BR>
-<A HREF="manual.html#and">and</A><BR>
-<A HREF="manual.html#appendto"><TT>appendto</TT></A><BR>
-<A HREF="manual.html#arg"><TT>arg</TT></A><BR>
-<A HREF="manual.html#arguments">arguments</A><BR>
-<A HREF="manual.html#arithmetic operators">arithmetic operators</A><BR>
-<A HREF="manual.html#arrays">arrays</A><BR>
-<A HREF="manual.html#asin"><TT>asin</TT></A><BR>
-<A HREF="manual.html#assert"><TT>assert</TT></A><BR>
-<A HREF="manual.html#Assignment">assignment</A><BR>
-<A HREF="manual.html#associative arrays">associative arrays</A><BR>
-<A HREF="manual.html#atan"><TT>atan</TT></A><BR>
-<A HREF="manual.html#atan2"><TT>atan2</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#Basic Expressions">basic expressions</A><BR>
-<A HREF="manual.html#basic types">basic types</A><BR>
-<A HREF="manual.html#block">block</A><BR>
-<A HREF="manual.html#break statement">break statement</A><BR>
-
-  <P>
-
-<A HREF="manual.html#C API">C API</A><BR>
-....... <A HREF="manual.html#LUA_ANYTAG"><TT>LUA_ANYTAG</TT></A><BR>
-....... <A HREF="manual.html#lua_baselibopen"><TT>lua_baselibopen</TT></A><BR>
-....... <A HREF="manual.html#lua_call"><TT>lua_call</TT></A><BR>
-....... <A HREF="manual.html#lua_CFunction"><TT>lua_CFunction</TT></A><BR>
-....... <A HREF="manual.html#lua_close"><TT>lua_close</TT></A><BR>
-....... <A HREF="manual.html#lua_concat"><TT>lua_concat</TT></A><BR>
-....... <A HREF="manual.html#lua_copytagmethods"><TT>lua_copytagmethods</TT></A><BR>
-....... <A HREF="manual.html#lua_dblibopen"><TT>lua_dblibopen</TT></A><BR>
-....... <A HREF="manual.html#lua_Debug"><TT>lua_Debug</TT></A><BR>
-....... <A HREF="manual.html#lua_dobuffer"><TT>lua_dobuffer</TT></A><BR>
-....... <A HREF="manual.html#lua_dofile"><TT>lua_dofile</TT></A><BR>
-....... <A HREF="manual.html#lua_dostring"><TT>lua_dostring</TT></A><BR>
-....... <A HREF="manual.html#lua_equal"><TT>lua_equal</TT></A><BR>
-....... <A HREF="manual.html#LUA_ERRERR"><TT>LUA_ERRERR</TT></A><BR>
-....... <A HREF="manual.html#LUA_ERRFILE"><TT>LUA_ERRFILE</TT></A><BR>
-....... <A HREF="manual.html#LUA_ERRMEM"><TT>LUA_ERRMEM</TT></A><BR>
-....... <A HREF="manual.html#lua_error"><TT>lua_error</TT></A><BR>
-....... <A HREF="manual.html#LUA_ERRRUN"><TT>LUA_ERRRUN</TT></A><BR>
-....... <A HREF="manual.html#LUA_ERRSYNTAX"><TT>LUA_ERRSYNTAX</TT></A><BR>
-....... <A HREF="manual.html#lua_getgccount"><TT>lua_getgccount</TT></A><BR>
-....... <A HREF="manual.html#lua_getgcthreshold"><TT>lua_getgcthreshold</TT></A><BR>
-....... <A HREF="manual.html#lua_getglobal"><TT>lua_getglobal</TT></A><BR>
-....... <A HREF="manual.html#lua_getglobals"><TT>lua_getglobals</TT></A><BR>
-....... <A HREF="manual.html#lua_getinfo"><TT>lua_getinfo</TT></A><BR>
-....... <A HREF="manual.html#lua_getlocal"><TT>lua_getlocal</TT></A><BR>
-....... <A HREF="manual.html#lua_getn"><TT>lua_getn</TT></A><BR>
-....... <A HREF="manual.html#lua_getref"><TT>lua_getref</TT></A><BR>
-....... <A HREF="manual.html#lua_getregistry"><TT>lua_getregistry</TT></A><BR>
-....... <A HREF="manual.html#lua_getstack"><TT>lua_getstack</TT></A><BR>
-....... <A HREF="manual.html#lua_gettable"><TT>lua_gettable</TT></A><BR>
-....... <A HREF="manual.html#lua_gettagmethod"><TT>lua_gettagmethod</TT></A><BR>
-....... <A HREF="manual.html#lua_gettop"><TT>lua_gettop</TT></A><BR>
-....... <A HREF="manual.html#lua_Hook"><TT>lua_Hook</TT></A><BR>
-....... <A HREF="manual.html#lua_insert"><TT>lua_insert</TT></A><BR>
-....... <A HREF="manual.html#lua_iolibopen"><TT>lua_iolibopen</TT></A><BR>
-....... <A HREF="manual.html#lua_iscfunction"><TT>lua_iscfunction</TT></A><BR>
-....... <A HREF="manual.html#lua_isfunction"><TT>lua_isfunction</TT></A><BR>
-....... <A HREF="manual.html#lua_isnil"><TT>lua_isnil</TT></A><BR>
-....... <A HREF="manual.html#lua_isnumber"><TT>lua_isnumber</TT></A><BR>
-....... <A HREF="manual.html#lua_isstring"><TT>lua_isstring</TT></A><BR>
-....... <A HREF="manual.html#lua_istable"><TT>lua_istable</TT></A><BR>
-....... <A HREF="manual.html#lua_isuserdata"><TT>lua_isuserdata</TT></A><BR>
-....... <A HREF="manual.html#lua_lessthan"><TT>lua_lessthan</TT></A><BR>
-....... <A HREF="manual.html#lua_mathlibopen"><TT>lua_mathlibopen</TT></A><BR>
-....... <A HREF="manual.html#LUA_MINSTACK"><TT>LUA_MINSTACK</TT></A><BR>
-....... <A HREF="manual.html#LUA_MULTRET"><TT>LUA_MULTRET</TT></A><BR>
-....... <A HREF="manual.html#lua_newtable"><TT>lua_newtable</TT></A><BR>
-....... <A HREF="manual.html#lua_newtag"><TT>lua_newtag</TT></A><BR>
-....... <A HREF="manual.html#lua_next"><TT>lua_next</TT></A><BR>
-....... <A HREF="manual.html#LUA_NOREF"><TT>LUA_NOREF</TT></A><BR>
-....... <A HREF="manual.html#lua_open"><TT>lua_open</TT></A><BR>
-....... <A HREF="manual.html#lua_pushcclosure"><TT>lua_pushcclosure</TT></A><BR>
-....... <A HREF="manual.html#lua_pushcfunction"><TT>lua_pushcfunction</TT></A><BR>
-....... <A HREF="manual.html#lua_pushlstring"><TT>lua_pushlstring</TT></A><BR>
-....... <A HREF="manual.html#lua_pushnil"><TT>lua_pushnil</TT></A><BR>
-....... <A HREF="manual.html#lua_pushnumber"><TT>lua_pushnumber</TT></A><BR>
-....... <A HREF="manual.html#lua_pushstring"><TT>lua_pushstring</TT></A><BR>
-....... <A HREF="manual.html#lua_pushuserdata"><TT>lua_pushuserdata</TT></A><BR>
-....... <A HREF="manual.html#lua_pushusertag"><TT>lua_pushusertag</TT></A><BR>
-....... <A HREF="manual.html#lua_pushvalue"><TT>lua_pushvalue</TT></A><BR>
-....... <A HREF="manual.html#lua_rawcall"><TT>lua_rawcall</TT></A><BR>
-....... <A HREF="manual.html#lua_rawget"><TT>lua_rawget</TT></A><BR>
-....... <A HREF="manual.html#lua_rawgeti"><TT>lua_rawgeti</TT></A><BR>
-....... <A HREF="manual.html#lua_rawset"><TT>lua_rawset</TT></A><BR>
-....... <A HREF="manual.html#lua_rawseti"><TT>lua_rawseti</TT></A><BR>
-....... <A HREF="manual.html#lua_ref"><TT>lua_ref</TT></A><BR>
-....... <A HREF="manual.html#LUA_REFNIL"><TT>LUA_REFNIL</TT></A><BR>
-....... <A HREF="manual.html#LUA_REFREGISTRY"><TT>LUA_REFREGISTRY</TT></A><BR>
-....... <A HREF="manual.html#lua_register"><TT>lua_register</TT></A><BR>
-....... <A HREF="manual.html#lua_remove"><TT>lua_remove</TT></A><BR>
-....... <A HREF="manual.html#lua_setcallhook"><TT>lua_setcallhook</TT></A><BR>
-....... <A HREF="manual.html#lua_setgcthreshold"><TT>lua_setgcthreshold</TT></A><BR>
-....... <A HREF="manual.html#lua_setglobal"><TT>lua_setglobal</TT></A><BR>
-....... <A HREF="manual.html#lua_setglobals"><TT>lua_setglobals</TT></A><BR>
-....... <A HREF="manual.html#lua_setlinehook"><TT>lua_setlinehook</TT></A><BR>
-....... <A HREF="manual.html#lua_setlocal"><TT>lua_setlocal</TT></A><BR>
-....... <A HREF="manual.html#lua_settable"><TT>lua_settable</TT></A><BR>
-....... <A HREF="manual.html#lua_settag"><TT>lua_settag</TT></A><BR>
-....... <A HREF="manual.html#lua_settagmethod"><TT>lua_settagmethod</TT></A><BR>
-....... <A HREF="manual.html#lua_settop"><TT>lua_settop</TT></A><BR>
-....... <A HREF="manual.html#lua_stackspace"><TT>lua_stackspace</TT></A><BR>
-....... <A HREF="manual.html#lua_State"><TT>lua_State</TT></A><BR>
-....... <A HREF="manual.html#lua_strlen"><TT>lua_strlen</TT></A><BR>
-....... <A HREF="manual.html#lua_strlibopen"><TT>lua_strlibopen</TT></A><BR>
-....... <A HREF="manual.html#lua_tag"><TT>lua_tag</TT></A><BR>
-....... <A HREF="manual.html#lua_tocfunction"><TT>lua_tocfunction</TT></A><BR>
-....... <A HREF="manual.html#lua_tonumber"><TT>lua_tonumber</TT></A><BR>
-....... <A HREF="manual.html#lua_tostring"><TT>lua_tostring</TT></A><BR>
-....... <A HREF="manual.html#lua_touserdata"><TT>lua_touserdata</TT></A><BR>
-....... <A HREF="manual.html#lua_type"><TT>lua_type</TT></A><BR>
-....... <A HREF="manual.html#lua_typename"><TT>lua_typename</TT></A><BR>
-....... <A HREF="manual.html#lua_unref"><TT>lua_unref</TT></A><BR>
-<A HREF="manual.html#C closure">C closure</A><BR>
-<A HREF="manual.html#C pointers">C pointers</A><BR>
-<A HREF="manual.html#call"><TT>call</TT></A><BR>
-<A HREF="manual.html#captures">captures</A><BR>
-<A HREF="manual.html#ceil"><TT>ceil</TT></A><BR>
-<A HREF="manual.html#character class">character class</A><BR>
-<A HREF="manual.html#chunk">chunk</A><BR>
-<A HREF="manual.html#clock"><TT>clock</TT></A><BR>
-<A HREF="manual.html#closefile"><TT>closefile</TT></A><BR>
-<A HREF="manual.html#closing a file">closing a file</A><BR>
-<A HREF="manual.html#Coercion">coercion</A><BR>
-<A HREF="manual.html#collectgarbage"><TT>collectgarbage</TT></A><BR>
-<A HREF="manual.html#Comments">comments</A><BR>
-<A HREF="manual.html#concatenation">concatenation</A><BR>
-<A HREF="manual.html#concatenation event">``concatenation'' event</A><BR>
-<A HREF="manual.html#condition expression">condition expression</A><BR>
-<A HREF="manual.html#constructors">constructors</A><BR>
-<A HREF="manual.html#copytagmethods"><TT>copytagmethods</TT></A><BR>
-<A HREF="manual.html#cos"><TT>cos</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#date"><TT>date</TT></A><BR>
-<A HREF="manual.html#def"><TT>def</TT></A><BR>
-<A HREF="manual.html#div event">``div'' event</A><BR>
-<A HREF="manual.html#dofile"><TT>dofile</TT></A><BR>
-<A HREF="manual.html#dostring"><TT>dostring</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#eight-bit clean">eight-bit clean</A><BR>
-<A HREF="manual.html#error"><TT>error</TT></A><BR>
-<A HREF="manual.html#event">event</A><BR>
-<A HREF="manual.html#execute"><TT>execute</TT></A><BR>
-<A HREF="manual.html#exit"><TT>exit</TT></A><BR>
-<A HREF="manual.html#exp"><TT>exp</TT></A><BR>
-<A HREF="manual.html#exponentiation">exponentiation</A><BR>
-<A HREF="manual.html#Expressions">expressions</A><BR>
-
-  <P>
-
-<A HREF="manual.html#file handles">file handles</A><BR>
-<A HREF="manual.html#floor"><TT>floor</TT></A><BR>
-<A HREF="manual.html#flush"><TT>flush</TT></A><BR>
-<A HREF="manual.html#for statement">for statement</A><BR>
-<A HREF="manual.html#foreach"><TT>foreach</TT></A><BR>
-<A HREF="manual.html#foreachi"><TT>foreachi</TT></A><BR>
-<A HREF="manual.html#format"><TT>format</TT></A><BR>
-<A HREF="manual.html#frexp"><TT>frexp</TT></A><BR>
-<A HREF="manual.html#function">function</A><BR>
-<A HREF="manual.html#function call">function call</A><BR>
-<A HREF="manual.html#Function Definitions">function definitions</A><BR>
-<A HREF="manual.html#function event">``function'' event</A><BR>
-
-  <P>
-
-<A HREF="manual.html#gc event">``gc'' event</A><BR>
-<A HREF="manual.html#getargs"><TT>getargs</TT></A><BR>
-<A HREF="manual.html#getenv"><TT>getenv</TT></A><BR>
-<A HREF="manual.html#getglobal"><TT>getglobal</TT></A><BR>
-<A HREF="manual.html#getglobal event">``getglobal'' event</A><BR>
-<A HREF="manual.html#getinfo"><TT>getinfo</TT></A><BR>
-<A HREF="manual.html#getlocal"><TT>getlocal</TT></A><BR>
-<A HREF="manual.html#getn"><TT>getn</TT></A><BR>
-<A HREF="manual.html#gettable event">``gettable'' event</A><BR>
-<A HREF="manual.html#gettagmethod"><TT>gettagmethod</TT></A><BR>
-<A HREF="manual.html#global environment">global environment</A><BR>
-<A HREF="manual.html#Global variables">global variables</A><BR>
-<A HREF="manual.html#globals"><TT>globals</TT></A><BR>
-<A HREF="manual.html#grammar">grammar</A><BR>
-....... <A HREF="manual.html#args">args</A><BR>
-....... <A HREF="manual.html#binop">binop</A><BR>
-....... <A HREF="manual.html#block">block</A><BR>
-....... <A HREF="manual.html#chunk">chunk</A><BR>
-....... <A HREF="manual.html#declist">declist</A><BR>
-....... <A HREF="manual.html#exp">exp</A><BR>
-....... <A HREF="manual.html#exp1">exp1</A><BR>
-....... <A HREF="manual.html#explist1">explist1</A><BR>
-....... <A HREF="manual.html#ffield">ffield</A><BR>
-....... <A HREF="manual.html#ffieldlist">ffieldlist</A><BR>
-....... <A HREF="manual.html#ffieldlist1">ffieldlist1</A><BR>
-....... <A HREF="manual.html#fieldlist">fieldlist</A><BR>
-....... <A HREF="manual.html#funcname">funcname</A><BR>
-....... <A HREF="manual.html#function">function</A><BR>
-....... <A HREF="manual.html#functioncall">functioncall</A><BR>
-....... <A HREF="manual.html#init">init</A><BR>
-....... <A HREF="manual.html#lfieldlist">lfieldlist</A><BR>
-....... <A HREF="manual.html#lfieldlist1">lfieldlist1</A><BR>
-....... <A HREF="manual.html#parlist1">parlist1</A><BR>
-....... <A HREF="manual.html#stat">stat</A><BR>
-....... <A HREF="manual.html#tableconstructor">tableconstructor</A><BR>
-....... <A HREF="manual.html#unop">unop</A><BR>
-....... <A HREF="manual.html#upvalue">upvalue</A><BR>
-....... <A HREF="manual.html#var">var</A><BR>
-....... <A HREF="manual.html#varlist1">varlist1</A><BR>
-....... <A HREF="manual.html#varorfunc">varorfunc</A><BR>
-<A HREF="manual.html#gsub"><TT>gsub</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#Identifiers">identifiers</A><BR>
-<A HREF="manual.html#if-then-else statement">if-then-else statement</A><BR>
-<A HREF="manual.html#index event">``index'' event</A><BR>
-
-  <P>
-
-<A HREF="manual.html#ldexp"><TT>ldexp</TT></A><BR>
-<A HREF="manual.html#Literal strings">literal strings</A><BR>
-<A HREF="manual.html#Local variables">local variables</A><BR>
-<A HREF="manual.html#log"><TT>log</TT></A><BR>
-<A HREF="manual.html#log10"><TT>log10</TT></A><BR>
-<A HREF="manual.html#logical operators">logical operators</A><BR>
-<A HREF="manual.html#lt event">``lt'' event</A><BR>
-<A HREF="manual.html#Lua Stand-alone">Lua stand-alone</A><BR>
-<A HREF="manual.html#luac"><TT>luac</TT></A><BR>
-
-  <P>
-
-<A HREF="manual.html#max"><TT>max</TT></A><BR>
-<A HREF="manual.html#methods">methods</A><BR>
-<A HREF="manual.html#min"><TT>min</TT></A><BR>
-<A HREF="manual.html#mod"><TT>mod</TT></A><BR>
-<A HREF="manual.html#mul event">``mul'' event</A><BR>
-<A HREF="manual.html#multiple assignment">multiple assignment</A><BR>
-
-  <P>
-
-<A HREF="manual.html#newtag"><TT>newtag</TT></A><BR>
-<A HREF="manual.html#next"><TT>next</TT></A><BR>
-<A HREF="manual.html#nil">nil</A><BR>
-<A HREF="manual.html#not">not</A><BR>
-<A HREF="manual.html#number">number</A><BR>
-<A HREF="manual.html#Numerical constants">numerical constants</A><BR>
-
-  <P>
-
-<A HREF="manual.html#openfile"><TT>openfile</TT></A><BR>
-<A HREF="manual.html#Operator precedence">operator precedence</A><BR>
-<A HREF="manual.html#or">or</A><BR>
-
-  <P>
-
-<A HREF="manual.html#pattern">pattern</A><BR>
-<A HREF="manual.html#pattern item">pattern item</A><BR>
-<A HREF="manual.html#PI"><TT>PI</TT></A><BR>
-<A HREF="manual.html#piped input">piped input</A><BR>
-<A HREF="manual.html#popen"><TT>popen</TT></A><BR>
-<A HREF="manual.html#pow event">``pow'' event</A><BR>
-<A HREF="manual.html#pre-compilation">pre-compilation</A><BR>
-<A HREF="manual.html#print"><TT>print</TT></A><BR>
-<A HREF="manual.html#protected calls">protected calls</A><BR>
-
-  <P>
-
-<A HREF="manual.html#rad"><TT>rad</TT></A><BR>
-<A HREF="manual.html#random"><TT>random</TT></A><BR>
-<A HREF="manual.html#randomseed"><TT>randomseed</TT></A><BR>
-<A HREF="manual.html#rawget"><TT>rawget</TT></A><BR>
-<A HREF="manual.html#rawset"><TT>rawset</TT></A><BR>
-<A HREF="manual.html#read"><TT>read</TT></A><BR>
-<A HREF="manual.html#readfrom"><TT>readfrom</TT></A><BR>
-<A HREF="manual.html#records">records</A><BR>
-<A HREF="manual.html#reference">reference</A><BR>
-<A HREF="manual.html#relational operators">relational operators</A><BR>
-<A HREF="manual.html#remove"><TT>remove</TT></A><BR>
-<A HREF="manual.html#rename"><TT>rename</TT></A><BR>
-<A HREF="manual.html#repeat-until statement">repeat-until statement</A><BR>
-<A HREF="manual.html#reserved words">reserved words</A><BR>
-<A HREF="manual.html#return statement">return statement</A><BR>
-
-  <P>
-
-<A HREF="manual.html#seek"><TT>seek</TT></A><BR>
-<A HREF="manual.html#self"><TT>self</TT></A><BR>
-<A HREF="manual.html#setcallhook"><TT>setcallhook</TT></A><BR>
-<A HREF="manual.html#setglobal"><TT>setglobal</TT></A><BR>
-<A HREF="manual.html#setglobal event">``setglobal'' event</A><BR>
-<A HREF="manual.html#setlinehook"><TT>setlinehook</TT></A><BR>
-<A HREF="manual.html#setlocal"><TT>setlocal</TT></A><BR>
-<A HREF="manual.html#setlocale"><TT>setlocale</TT></A><BR>
-<A HREF="manual.html#settable event">``settable'' event</A><BR>
-<A HREF="manual.html#settag"><TT>settag</TT></A><BR>
-<A HREF="manual.html#settagmethod"><TT>settagmethod</TT></A><BR>
-<A HREF="manual.html#short-cut evaluation">short-cut evaluation</A><BR>
-<A HREF="manual.html#sin"><TT>sin</TT></A><BR>
-<A HREF="manual.html#sort"><TT>sort</TT></A><BR>
-<A HREF="manual.html#sqrt"><TT>sqrt</TT></A><BR>
-<A HREF="manual.html#stack index">stack index</A><BR>
-<A HREF="manual.html#state">state</A><BR>
-<A HREF="manual.html#statements">statements</A><BR>
-<A HREF="manual.html#stderr"><TT>stderr</TT></A><BR>
-<A HREF="manual.html#strbyte"><TT>strbyte</TT></A><BR>
-<A HREF="manual.html#strchar"><TT>strchar</TT></A><BR>
-<A HREF="manual.html#strfind"><TT>strfind</TT></A><BR>
-<A HREF="manual.html#string">string</A><BR>
-<A HREF="manual.html#strlen"><TT>strlen</TT></A><BR>
-<A HREF="manual.html#strlower"><TT>strlower</TT></A><BR>
-<A HREF="manual.html#strrep"><TT>strrep</TT></A><BR>
-<A HREF="manual.html#strsub"><TT>strsub</TT></A><BR>
-<A HREF="manual.html#strupper"><TT>strupper</TT></A><BR>
-<A HREF="manual.html#sub event">``sub'' event</A><BR>
-
-  <P>
-
-<A HREF="manual.html#table">table</A><BR>
-<A HREF="manual.html#tag">tag</A><BR>
-<A HREF="manual.html#tag"><TT>tag</TT></A><BR>
-<A HREF="manual.html#tag method">tag method</A><BR>
-....... <A HREF="manual.html#add">add</A><BR>
-....... <A HREF="manual.html#concatenation">concatenation</A><BR>
-....... <A HREF="manual.html#div">div</A><BR>
-....... <A HREF="manual.html#function">function</A><BR>
-....... <A HREF="manual.html#gc">gc</A><BR>
-....... <A HREF="manual.html#getglobal">getglobal</A><BR>
-....... <A HREF="manual.html#gettable">gettable</A><BR>
-....... <A HREF="manual.html#index">index</A><BR>
-....... <A HREF="manual.html#lt">lt</A><BR>
-....... <A HREF="manual.html#mul">mul</A><BR>
-....... <A HREF="manual.html#pow">pow</A><BR>
-....... <A HREF="manual.html#setglobal">setglobal</A><BR>
-....... <A HREF="manual.html#settable">settable</A><BR>
-....... <A HREF="manual.html#sub">sub</A><BR>
-....... <A HREF="manual.html#unm">unm</A><BR>
-<A HREF="manual.html#tan"><TT>tan</TT></A><BR>
-<A HREF="manual.html#tinsert"><TT>tinsert</TT></A><BR>
-<A HREF="manual.html#tmpname"><TT>tmpname</TT></A><BR>
-<A HREF="manual.html#tokens">tokens</A><BR>
-<A HREF="manual.html#tonumber"><TT>tonumber</TT></A><BR>
-<A HREF="manual.html#tostring"><TT>tostring</TT></A><BR>
-<A HREF="manual.html#tremove"><TT>tremove</TT></A><BR>
-<A HREF="manual.html#type"><TT>type</TT></A><BR>
-<A HREF="manual.html#Types and Tags">types and tags</A><BR>
-
-  <P>
-
-<A HREF="manual.html#unm event">``unm'' event</A><BR>
-<A HREF="manual.html#upvalues">upvalues</A><BR>
-<A HREF="manual.html#userdata">userdata</A><BR>
-
-  <P>
-
-<A HREF="manual.html#valid index">valid index</A><BR>
-<A HREF="manual.html#vararg function">vararg function</A><BR>
-<A HREF="manual.html#version 3.2">version 3.2</A><BR>
-<A HREF="manual.html#visibility">visibility</A><BR>
-
-  <P>
-
-<A HREF="manual.html#while-do statement">while-do statement</A><BR>
-<A HREF="manual.html#write"><TT>write</TT></A><BR>
-<A HREF="manual.html#writeto"><TT>writeto</TT></A><BR>
-
-  <P>
-
-
-<HR>
-<SMALL>
-Last update:
-Mon Nov  6 17:35:51 EDT 2000
-by <A HREF="http://www.tecgraf.puc-rio.br/~lhf/">lhf</A>.
-</SMALL>
-
-</BODY>
-</HTML>
diff --git a/doc/index.html b/doc/index.html
deleted file mode 100644
index b7603a30..00000000
--- a/doc/index.html
+++ /dev/null
@@ -1,93 +0,0 @@
-<HTML>
-<HEAD>
-<TITLE>Lua: reference manual - contents</TITLE>
-</HEAD>
-
-<BODY BGCOLOR="#FFFFFF">
-
-<HR>
-<H1>
-<IMG SRC="logo.gif" ALT="Lua" ALIGN="bottom">
-Reference manual
-</H1>
-
-<A HREF="manual.html">
-Reference Manual of the Programming Language
-<A HREF="http://www.tecgraf.puc-rio.br/lua/">Lua</A>
-4.0</A>
-[
-<A HREF="manual.html">top</A>
-|
-<A HREF="idx.html">index</A>
-|
-<A HREF="ftp://ftp.tecgraf.puc-rio.br/pub/lua/refman.ps.gz">ps</A>
-|
-<A HREF="ftp://ftp.tecgraf.puc-rio.br/pub/lua/refman.pdf">pdf</A>
-|
-<A HREF="old/">old versions</A>
-]
-<P>
-<A NAME="contents"></A>
-<UL>
-<LI><A HREF="manual.html#1.">1 - Introduction</A>
-<LI><A HREF="manual.html#2.">2 - Environment and Chunks</A>
-<LI><A HREF="manual.html#3.">3 - Types and Tags</A> 
-<LI><A HREF="manual.html#4.">4 - The Language</A>
- <UL>
- <LI><A HREF="manual.html#4.1">4.1 - Lexical Conventions</A> 
- <LI><A HREF="manual.html#4.2">4.2 - Coercion</A> 
- <LI><A HREF="manual.html#4.3">4.3 - Adjustment</A> 
- <LI><A HREF="manual.html#4.4">4.4 - Statements</A>
- <LI><A HREF="manual.html#4.5">4.5 - Expressions</A>
- <LI><A HREF="manual.html#4.6">4.6 - Visibility and Upvalues</A> 
- <LI><A HREF="manual.html#4.7">4.7 - Error Handling</A> 
- <LI><A HREF="manual.html#4.8">4.8 - Tag Methods</A> 
- </UL>
-<LI><A HREF="manual.html#5.">5 - The Application Program Interface</A>
- <UL>
- <LI><A HREF="manual.html#5.1">5.1 - States</A> 
- <LI><A HREF="manual.html#5.2">5.2 - The Stack and Indices</A>
- <LI><A HREF="manual.html#5.3">5.3 - Stack Manipulation</A>
- <LI><A HREF="manual.html#5.4">5.4 - Querying the Stack</A>
- <LI><A HREF="manual.html#5.5">5.5 - Pushing values onto the Stack</A>
- <LI><A HREF="manual.html#5.6">5.6 - Garbage Collection</A>
- <LI><A HREF="manual.html#5.7">5.7 - Userdata and Tags</A>
- <LI><A HREF="manual.html#5.8">5.8 - Executing Lua Code</A>
- <LI><A HREF="manual.html#5.9">5.9 - Manipulating Global Variables in Lua</A>
- <LI><A HREF="manual.html#5.10">5.10 - Manipulating Tables in Lua</A>
- <LI><A HREF="manual.html#5.11">5.11 - Using Tables as Arrays</A>
- <LI><A HREF="manual.html#5.12">5.12 - Calling Lua Functions</A>
- <LI><A HREF="manual.html#5.13">5.13 - Defining C Functions</A> 
- <LI><A HREF="manual.html#5.14">5.14 - References to Lua Objects</A>
- </UL>
-<LI><A HREF="manual.html#6.">6 - Standard Libraries</A>
- <UL>
- <LI><A HREF="manual.html#6.1">6.1 - Basic Functions</A> 
- <LI><A HREF="manual.html#6.2">6.2 - String Manipulation</A>
- <LI><A HREF="manual.html#6.3">6.3 - Mathematical Functions</A> 
- <LI><A HREF="manual.html#6.4">6.4 - I/O Facilities</A> 
- <LI><A HREF="manual.html#6.5">6.5 - System Facilities</A> 
- </UL>
-<LI><A HREF="manual.html#7.">7 - The Debug Interface</A> 
- <UL>
- <LI><A HREF="manual.html#7.1">7.1 - Stack and Function Information</A>
- <LI><A HREF="manual.html#7.2">7.2 - Manipulating Local Variables</A>
- <LI><A HREF="manual.html#7.3">7.3 - Hooks</A>
- <LI><A HREF="manual.html#7.4">7.4 - The Reflexive Debug Interface</A>
- </UL>
-<LI><A HREF="manual.html#8.">8 - Lua Stand-alone</A> 
-<LI><A HREF="manual.html#Acknowledgments">Acknowledgments</A>
-<LI><A HREF="manual.html#Incompatibilities">Incompatibilities with Previous Versions</A>
-<LI><A HREF="manual.html#BNF">The Complete Syntax of Lua</A> 
-<LI><A HREF="idx.html">Index</A>
-</UL>
-
-<HR>
-<SMALL>
-Last update:
-Mon Nov  6 17:36:08 EDT 2000
-by <A HREF="http://www.tecgraf.puc-rio.br/~lhf/">lhf</A>.
-</SMALL>
-
-</BODY>
-</HTML>
diff --git a/doc/logo.gif b/doc/logo.gif
index f3e68936..2f5e4ac2 100644
--- a/doc/logo.gif
+++ b/doc/logo.gif
diff --git a/doc/lua.1 b/doc/lua.1
index b1561818..c9bba7d7 100644
--- a/doc/lua.1
+++ b/doc/lua.1
@@ -1,137 +1,161 @@
-.\" lua.man,v 1.3 2000/09/04 21:41:28 lhf Exp
-.TH LUA 1 "2000/09/04 21:41:28"
+.\" lua.man,v 1.8 2003/04/02 00:05:20 lhf Exp
+.TH LUA 1 "2003/04/02 00:05:20"
 .SH NAME
 lua \- Lua interpreter
 .SH SYNOPSIS
 .B lua
 [
-.I arguments
+.I options
+]
+[
+.I script
+[
+.I args
+]
 ]
 .SH DESCRIPTION
 .B lua
 is the stand-alone Lua interpreter.
 It loads and executes Lua programs,
 either in textual source form or
-in precompiled binary form,
-as output by
+in precompiled binary form.
+(Precompiled binaries are output by
 .BR luac ,
-the Lua compiler.
+the Lua compiler.)
 .B lua
 can be used as a batch interpreter and also interactively.
 .LP
-The
-.I arguments
-can be options, assignments, or filenames,
-and are processed in order,
-from left to right.
+The given
+.I options
+(see below)
+are executed and then
+the Lua program in file
+.I script
+is loaded and executed.
+The given
+.I args
+are available to
+.I script
+as strings in a global table named
+.BR arg .
+If these arguments contain spaces or other characters special to the shell,
+then they should be quoted
+(but note that the quotes will be removed by the shell).
+The arguments in
+.B arg
+start at 0,
+which contains the string
+.RI ` script '.
+The index of the last argument is stored in
+.BR "arg.n" .
+The arguments given in the command line before
+.IR script ,
+including the name of the interpreter,
+are available in negative indices in
+.BR arg .
+.LP
+At the very start,
+before even handling the command line,
+.B lua
+executes the contents of the environment variable
+.BR LUA_INIT ,
+if it is defined.
+If the value of
+.B LUA_INIT
+is of the form
+.RI `@ filename ',
+then
+.I filename
+is executed.
+Otherwise, the string is assumed to be a Lua statement and is executed.
 .LP
 Options start with
 .B \-
 and are described below.
-.LP
-An assignment is an argument of the form
-.BR a=b ,
-which assigns the string
-.RB ` b '
-to the global variable
-.BR a .
-Note that no quotes are needed around the string if it does not contain spaces
-or other characters special to the shell.
-This is for convenience only.
-(In general,
-you should be careful when using quotes and spaces on the command line
-because they are usually handled by the shell.)
-.LP
-If the argument is neither an option nor an assignment,
-then it is assumed to be a filename,
-which is then loaded and executed.
+You can use
+.B "\--"
+to signal the end of options.
 .LP
 If no arguments are given,
 then
 .B "\-v \-i"
 is assumed when the standard input is a terminal;
 otherwise,
-.B \-
+.B "\-"
 is assumed.
+.LP
+In interactive mode,
+.B lua
+prompts the user,
+reads lines from the standard input,
+and executes them as they are read.
+If a line does not contain a complete statement,
+then a secondary prompt is displayed and
+lines are read until a complete statement is formed or
+a syntax error is found.
+So, one way to interrupt the reading of an incomplete statement is
+to force a syntax error:
+adding a
+.B `;' 
+in the middle of a statement is a sure way of forcing a syntax error
+(except inside multiline strings and comments; these must be closed explicitly).
+If a line starts with
+.BR `=' ,
+then
+.B lua
+displays the values of all the expressions in the remainder of the
+line. The expressions must be separated by commas.
+The primary prompt is the value of the global variable
+.BR _PROMPT ,
+if this value is a string;
+otherwise, the default prompt is used.
+Similarly, the secondary prompt is the value of the global variable
+.BR _PROMPT2 .
+So,
+to change the prompts,
+set the corresponding variable to a string of your choice.
+You can do that after calling the interpreter
+or on the command line with
+.BR "_PROMPT" "=\'lua: \'" ,
+for example.
+(Note the need for quotes, because the string contains a space.)
+The default prompts are ``> '' and ``>> ''.
 .SH OPTIONS
 .TP
 .B \-
-load the standard input as a file,
+load and execute the standard input as a file,
 that is,
 not interactively,
 even when the standard input is a terminal.
 .TP
-.B \-c
-close Lua before exiting.
-.TP
 .BI \-e " stat"
 execute statement
 .IR stat .
-You will need to quote
+You need to quote
 .I stat 
-if it contains spaces or quotes.
-.TP
-.BI \-f " file"
-collect all remaining arguments as strings into a global table named
-.B arg
-and then execute
-.IR file .
-The arguments in
-.B arg
-start at 0,
-which contains the string
-.RI ` file '.
-The index of the last argument is stored in
-.BR "arg.n" .
+if it contains spaces, quotes,
+or other characters special to the shell.
 .TP
 .B \-i
-enter interactive mode,
-displaying a prompt.
-In this mode,
-.B lua
-reads lines from the standard input and executes them as they are read.
-Each line must contain a complete statement.
-To span a statement across several lines, end each line with a backslash
-.BR `\e' .
-The prompt shown is the value of the global variable
-.BR _PROMPT ,
-if this value is a string.
-So,
-to change the prompt,
-set
-.B _PROMPT
-to a string of your choice.
-You can do that after calling the interpreter
-or on the command line with
-.BR "_PROMPT=\'lua: \'" ,
-for example.
-(Note the need for quotes, because the string contains a space.)
-The default prompt is ``> ''.
-.TP
-.B \-q
-enter interactive mode,
-but without displaying a prompt.
+enter interactive mode after
+.I script
+is executed.
 .TP
-.BI \-s n
-set the stack size to
-.IB n .
-If present,
-this must be the first option.
-Note that
-.I n
-is in the same argument as
-.BR -s .
-For example,
-to specify a stack size of 2000,
-use
-.BR -s2000 .
+.BI \-l " file"
+call
+.BI require( file )
+before executing
+.IR script.
+Typically used to load libraries
+(hence the letter
+.IR l ).
 .TP
 .B \-v
-print version information.
+show version information.
 .SH "SEE ALSO"
 .BR luac (1)
 .br
-http://www.tecgraf.puc-rio.br/lua/
+http://www.lua.org/
 .SH DIAGNOSTICS
 Error messages should be self explanatory.
 .SH AUTHORS
diff --git a/doc/lua.html b/doc/lua.html
index ef861bb5..073d4b52 100644
--- a/doc/lua.html
+++ b/doc/lua.html
@@ -1,4 +1,4 @@
-<!-- lua.man,v 1.3 2000/09/04 21:41:28 lhf Exp -->
+<!-- lua.man,v 1.8 2003/04/02 00:05:20 lhf Exp -->
 <HTML>
 <HEAD>
 <TITLE>LUA man page</TITLE>
@@ -11,133 +11,157 @@ lua - Lua interpreter
 <H1>SYNOPSIS</H1>
 <B>lua</B>
 [
-<I>arguments</I>
+<I>options</I>
+]
+[
+<I>script</I>
+[
+<I>args</I>
+]
 ]
 <H1>DESCRIPTION</H1>
 <B>lua</B>
 is the stand-alone Lua interpreter.
 It loads and executes Lua programs,
 either in textual source form or
-in precompiled binary form,
-as output by
+in precompiled binary form.
+(Precompiled binaries are output by
 <B>luac</B>,
-the Lua compiler.
+the Lua compiler.)
 <B>lua</B>
 can be used as a batch interpreter and also interactively.
 <P>
-The
-<I>arguments</I>
-can be options, assignments, or filenames,
-and are processed in order,
-from left to right.
+The given
+<I>options</I>
+(see below)
+are executed and then
+the Lua program in file
+<I>script</I>
+is loaded and executed.
+The given
+<I>args</I>
+are available to
+<I>script</I>
+as strings in a global table named
+<B>arg</B>.
+If these arguments contain spaces or other characters special to the shell,
+then they should be quoted
+(but note that the quotes will be removed by the shell).
+The arguments in
+<B>arg</B>
+start at 0,
+which contains the string
+`<I>script</I>'.
+The index of the last argument is stored in
+<B>"arg.n"</B>.
+The arguments given in the command line before
+<I>script</I>,
+including the name of the interpreter,
+are available in negative indices in
+<B>arg</B>.
+<P>
+At the very start,
+before even handling the command line,
+<B>lua</B>
+executes the contents of the environment variable
+<B>LUA_INIT</B>,
+if it is defined.
+If the value of
+<B>LUA_INIT</B>
+is of the form
+`@<I>filename</I>',
+then
+<I>filename</I>
+is executed.
+Otherwise, the string is assumed to be a Lua statement and is executed.
 <P>
 Options start with
 <B>-</B>
 and are described below.
-<P>
-An assignment is an argument of the form
-<B>a=b</B>,
-which assigns the string
-.RB ` b '
-to the global variable
-<B>a</B>.
-Note that no quotes are needed around the string if it does not contain spaces
-or other characters special to the shell.
-This is for convenience only.
-(In general,
-you should be careful when using quotes and spaces on the command line
-because they are usually handled by the shell.)
-<P>
-If the argument is neither an option nor an assignment,
-then it is assumed to be a filename,
-which is then loaded and executed.
+You can use
+<B>"--"</B>
+to signal the end of options.
 <P>
 If no arguments are given,
 then
 <B>"-v -i"</B>
 is assumed when the standard input is a terminal;
 otherwise,
-<B>-</B>
+<B>"-"</B>
 is assumed.
+<P>
+In interactive mode,
+<B>lua</B>
+prompts the user,
+reads lines from the standard input,
+and executes them as they are read.
+If a line does not contain a complete statement,
+then a secondary prompt is displayed and
+lines are read until a complete statement is formed or
+a syntax error is found.
+So, one way to interrupt the reading of an incomplete statement is
+to force a syntax error:
+adding a
+<B>`;' </B>
+in the middle of a statement is a sure way of forcing a syntax error
+(except inside multiline strings and comments; these must be closed explicitly).
+If a line starts with
+<B>`='</B>,
+then
+<B>lua</B>
+displays the values of all the expressions in the remainder of the
+line. The expressions must be separated by commas.
+The primary prompt is the value of the global variable
+<B>_PROMPT</B>,
+if this value is a string;
+otherwise, the default prompt is used.
+Similarly, the secondary prompt is the value of the global variable
+<B>_PROMPT2</B>.
+So,
+to change the prompts,
+set the corresponding variable to a string of your choice.
+You can do that after calling the interpreter
+or on the command line with
+<B>"_PROMPT" "=\'lua: \'"</B>,
+for example.
+(Note the need for quotes, because the string contains a space.)
+The default prompts are ``&gt; '' and ``&gt;&gt; ''.
 <H1>OPTIONS</H1>
 <P>
 <B>-</B>
-load the standard input as a file,
+load and execute the standard input as a file,
 that is,
 not interactively,
 even when the standard input is a terminal.
 <P>
-<B>-c</B>
-close Lua before exiting.
-<P>
 <B>-e "</B><I>stat"</I>
 execute statement
 <I>stat</I>.
-You will need to quote
+You need to quote
 <I>stat </I>
-if it contains spaces or quotes.
-<P>
-<B>-f "</B><I>file"</I>
-collect all remaining arguments as strings into a global table named
-<B>arg</B>
-and then execute
-<I>file</I>.
-The arguments in
-<B>arg</B>
-start at 0,
-which contains the string
-.RI ` file '.
-The index of the last argument is stored in
-<B>"arg.n"</B>.
+if it contains spaces, quotes,
+or other characters special to the shell.
 <P>
 <B>-i</B>
-enter interactive mode,
-displaying a prompt.
-In this mode,
-<B>lua</B>
-reads lines from the standard input and executes them as they are read.
-Each line must contain a complete statement.
-To span a statement across several lines, end each line with a backslash
-<B>`\e'</B>.
-The prompt shown is the value of the global variable
-<B>_PROMPT</B>,
-if this value is a string.
-So,
-to change the prompt,
-set
-<B>_PROMPT</B>
-to a string of your choice.
-You can do that after calling the interpreter
-or on the command line with
-<B>"_PROMPT=\'lua: \'"</B>,
-for example.
-(Note the need for quotes, because the string contains a space.)
-The default prompt is ``&gt; ''.
-<P>
-<B>-q</B>
-enter interactive mode,
-but without displaying a prompt.
+enter interactive mode after
+<I>script</I>
+is executed.
 <P>
-<B>-s</B><I>n</I>
-set the stack size to
-.IB n .
-If present,
-this must be the first option.
-Note that
-<I>n</I>
-is in the same argument as
-<B>-s</B>.
-For example,
-to specify a stack size of 2000,
-use
-<B>-s2000</B>.
+<B>-l "</B><I>file"</I>
+call
+<B>require( file</B><I>)</I>
+before executing
+<I></I>script.
+Typically used to load libraries
+(hence the letter
+<I>l</I>).
 <P>
 <B>-v</B>
-print version information.
+show version information.
 <H1>SEE ALSO</H1>
 <B>luac</B>(1)
 <BR>
-<A HREF="http://www.tecgraf.puc-rio.br/lua/">http://www.tecgraf.puc-rio.br/lua/</A>
+<A HREF="http://www.lua.org/">http://www.lua.org/</A>
 <H1>DIAGNOSTICS</H1>
 Error messages should be self explanatory.
 <H1>AUTHORS</H1>
@@ -145,7 +169,7 @@ R. Ierusalimschy,
 L. H. de Figueiredo,
 and
 W. Celes
-(<A HREF="mailto:lua@tecgraf.puc-rio.br">lua@tecgraf.puc-rio.br</A>)
+(<A HREF="mailto:lua-NO-SPAM-THANKS@tecgraf.puc-rio.br">lua AT tecgraf.puc-rio.br</A>)
 <!-- EOF -->
 </BODY>
 </HTML>
diff --git a/doc/luac.1 b/doc/luac.1
index 212f9b61..c6523060 100644
--- a/doc/luac.1
+++ b/doc/luac.1
@@ -1,5 +1,5 @@
-.\" luac.man,v 1.20 2000/10/06 15:11:21 lhf Exp
-.TH LUAC 1 "2000/10/06 15:11:21"
+.\" luac.man,v 1.25 2002/12/13 11:45:12 lhf Exp
+.TH LUAC 1 "2002/12/13 11:45:12"
 .SH NAME
 luac \- Lua compiler
 .SH SYNOPSIS
@@ -13,17 +13,13 @@ luac \- Lua compiler
 .B luac
 is the Lua compiler.
 It translates programs written in the Lua programming language
-into binary files that can be loaded and executed with
-.B lua_dofile
-in C or with
-.B dofile
-in Lua.
+into binary files that can be latter loaded and executed.
 .LP
 The main advantages of precompiling chunks are:
 faster loading,
 protecting source code from user changes,
 and
-off-line syntax error detection.
+off-line syntax checking.
 .LP
 Pre-compiling does not imply faster execution
 because in Lua chunks are always compiled into bytecodes before being executed.
@@ -46,9 +42,10 @@ are portable to all architectures with the same word size.
 This means that
 binary files created on a 32-bit platform (such as Intel)
 can be read without change in another 32-bit platform (such as Sparc),
-even if the byte order (``endianess'') is different.
+even if the byte order (``endianness'') is different.
 On the other hand,
-binary files created on a 16-bit platform cannot be read in a 32-bit platform.
+binary files created on a 16-bit platform cannot be read in a 32-bit platform,
+nor vice-versa.
 .LP
 In the command line,
 you can mix
@@ -60,15 +57,17 @@ into a single precompiled chunk.
 .LP
 You can use
 .B "\-"
-to indicate
-.I stdin
-as a source file.
+to indicate the standard input as a source file
+and
+.B "\--"
+to signal the end of options
+(that is,
+all remaining arguments will be treated as files even if they start with
+.BR "\-" ).
 .LP
 The internal format of the binary files produced by
 .B luac
-may change when a new version of Lua is released.
-We try to maintain compatibility even for binary files,
-but it is not always possible.
+is likely to change when a new version of Lua is released.
 So,
 save the source files of all Lua programs that you precompile.
 .LP
@@ -89,26 +88,16 @@ output to
 .IR file ,
 instead of the default
 .BR luac.out .
-The output file can be a source file because
+The output file may be a source file because
 all files are loaded before the output file is written.
+Be careful not to overwrite precious files.
 .TP
 .B \-p
 load files but do not generate any output file.
-Used mainly for syntax checking or testing precompiled chunks:
+Used mainly for syntax checking and for testing precompiled chunks:
 corrupted files will probably generate errors when loaded.
-For a thourough integrity test,
-use
-.BR \-t .
-.TP
-.B \-s
-strip debug information before writing the output file.
-This saves some space in very large chunks,
-but if errors occur when running these chunks,
-then the error messages might not contain the full information they usually do.
-.TP
-.B \-t
-perform a thourough integrity test of precompiled chunks.
-Code that passes this test is completely safe,
+Lua always performs a thorough integrity test on precompiled chunks.
+Bytecode that passes this test is completely safe,
 in the sense that it will not break the interpreter.
 However,
 there is no guarantee that such code does anything sensible.
@@ -118,9 +107,17 @@ If no files are given, then
 loads
 .B luac.out
 and tests its contents.
+No messages are displayed if the file passes the integrity test.
+.TP
+.B \-s
+strip debug information before writing the output file.
+This saves some space in very large chunks,
+but if errors occur when running these chunks,
+then the error messages may not contain the full information they usually do
+(line numbers and names of locals are lost).
 .TP
 .B \-v
-print version information.
+show version information.
 .SH FILES
 .TP 15
 .B luac.out
@@ -128,7 +125,7 @@ default output file
 .SH "SEE ALSO"
 .BR lua (1)
 .br
-http://www.tecgraf.puc-rio.br/lua/
+http://www.lua.org/
 .SH DIAGNOSTICS
 Error messages should be self explanatory.
 .SH AUTHORS
diff --git a/doc/luac.html b/doc/luac.html
index e083c2b3..3a71622e 100644
--- a/doc/luac.html
+++ b/doc/luac.html
@@ -1,4 +1,4 @@
-<!-- luac.man,v 1.20 2000/10/06 15:11:21 lhf Exp -->
+<!-- luac.man,v 1.25 2002/12/13 11:45:12 lhf Exp -->
 <HTML>
 <HEAD>
 <TITLE>LUAC man page</TITLE>
@@ -19,17 +19,13 @@ luac - Lua compiler
 <B>luac</B>
 is the Lua compiler.
 It translates programs written in the Lua programming language
-into binary files that can be loaded and executed with
-<B>lua_dofile</B>
-in C or with
-<B>dofile</B>
-in Lua.
+into binary files that can be latter loaded and executed.
 <P>
 The main advantages of precompiling chunks are:
 faster loading,
 protecting source code from user changes,
 and
-off-line syntax error detection.
+off-line syntax checking.
 <P>
 Pre-compiling does not imply faster execution
 because in Lua chunks are always compiled into bytecodes before being executed.
@@ -52,9 +48,10 @@ are portable to all architectures with the same word size.
 This means that
 binary files created on a 32-bit platform (such as Intel)
 can be read without change in another 32-bit platform (such as Sparc),
-even if the byte order (``endianess'') is different.
+even if the byte order (``endianness'') is different.
 On the other hand,
-binary files created on a 16-bit platform cannot be read in a 32-bit platform.
+binary files created on a 16-bit platform cannot be read in a 32-bit platform,
+nor vice-versa.
 <P>
 In the command line,
 you can mix
@@ -66,15 +63,17 @@ into a single precompiled chunk.
 <P>
 You can use
 <B>"-"</B>
-to indicate
-<I>stdin</I>
-as a source file.
+to indicate the standard input as a source file
+and
+<B>"--"</B>
+to signal the end of options
+(that is,
+all remaining arguments will be treated as files even if they start with
+<B>"-"</B>).
 <P>
 The internal format of the binary files produced by
 <B>luac</B>
-may change when a new version of Lua is released.
-We try to maintain compatibility even for binary files,
-but it is not always possible.
+is likely to change when a new version of Lua is released.
 So,
 save the source files of all Lua programs that you precompile.
 <P>
@@ -95,26 +94,16 @@ output to
 <I>file</I>,
 instead of the default
 <B>luac.out</B>.
-The output file can be a source file because
+The output file may be a source file because
 all files are loaded before the output file is written.
+Be careful not to overwrite precious files.
 <P>
 <B>-p</B>
 load files but do not generate any output file.
-Used mainly for syntax checking or testing precompiled chunks:
+Used mainly for syntax checking and for testing precompiled chunks:
 corrupted files will probably generate errors when loaded.
-For a thourough integrity test,
-use
-<B>-t</B>.
-<P>
-<B>-s</B>
-strip debug information before writing the output file.
-This saves some space in very large chunks,
-but if errors occur when running these chunks,
-then the error messages might not contain the full information they usually do.
-<P>
-<B>-t</B>
-perform a thourough integrity test of precompiled chunks.
-Code that passes this test is completely safe,
+Lua always performs a thorough integrity test on precompiled chunks.
+Bytecode that passes this test is completely safe,
 in the sense that it will not break the interpreter.
 However,
 there is no guarantee that such code does anything sensible.
@@ -124,9 +113,17 @@ If no files are given, then
 loads
 <B>luac.out</B>
 and tests its contents.
+No messages are displayed if the file passes the integrity test.
+<P>
+<B>-s</B>
+strip debug information before writing the output file.
+This saves some space in very large chunks,
+but if errors occur when running these chunks,
+then the error messages may not contain the full information they usually do
+(line numbers and names of locals are lost).
 <P>
 <B>-v</B>
-print version information.
+show version information.
 <H1>FILES</H1>
 <P>
 <B>luac.out</B>
@@ -134,14 +131,14 @@ default output file
 <H1>SEE ALSO</H1>
 <B>lua</B>(1)
 <BR>
-<A HREF="http://www.tecgraf.puc-rio.br/lua/">http://www.tecgraf.puc-rio.br/lua/</A>
+<A HREF="http://www.lua.org/">http://www.lua.org/</A>
 <H1>DIAGNOSTICS</H1>
 Error messages should be self explanatory.
 <H1>AUTHORS</H1>
 L. H. de Figueiredo,
 R. Ierusalimschy and
 W. Celes
-(<A HREF="mailto:lua@tecgraf.puc-rio.br">lua@tecgraf.puc-rio.br</A>)
+(<A HREF="mailto:lua-NO-SPAM-THANKS@tecgraf.puc-rio.br">lua AT tecgraf.puc-rio.br</A>)
 <!-- EOF -->
 </BODY>
 </HTML>
diff --git a/doc/manual.html b/doc/manual.html
index 703bd165..17a932f2 100644
--- a/doc/manual.html
+++ b/doc/manual.html
@@ -1,948 +1,1025 @@
-<HTML>
-<HEAD>
-<TITLE>Lua: reference manual 4.0</TITLE>
-</HEAD>
-
-<BODY BGCOLOR="#FFFFFF">
-
-<HR>
-<H1>
-<IMG SRC="logo.gif" ALT="Lua" ALIGN="bottom">
-Reference Manual of the Programming Language
-<A HREF="http://www.tecgraf.puc-rio.br/lua/">Lua</A>
-4.0
-</H1>
-
-<!--  $Id: manual.tex,v 1.45 2000/10/31 18:20:01 roberto Exp roberto $ -->
-<P>
-<P>
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
+<html>
+
+<head>
+<title>Lua 5.0 Reference Manual</title>
+</head>
+
+<body BGCOLOR="#FFFFFF">
+
+<hr>
+<h1>
+<a HREF="http://www.lua.org/home.html">
+<img SRC="logo.gif" ALT="[Lua logo]" BORDER=0>
+</a>
+Lua 5.0 Reference Manual
+</h1>
+
+by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes
+<p>
+<small>
+<a HREF="http://www.lua.org/copyright.html">Copyright</a>
+&copy; 2003 TeCGraf, PUC-Rio.  All rights reserved.
+</small>
+<hr>
+
+<p>
+<p>
 <!-- ====================================================================== -->
-<HR>
-<A NAME="1."></A>
-<H1>1 - Introduction</H1>
-<P>
-Lua is an extension programming language designed to support
+
+
+
+<h1>1 - Introduction</h1>
+
+<p>Lua is an extension programming language designed to support
 general procedural programming with data description
 facilities.
+It also offers good suport for object-oriented programming,
+functional programming, and data-driven programming.
 Lua is intended to be used as a powerful, light-weight
 configuration language for any program that needs one.
-<P>
-Lua is implemented as a library, written in C.
-Being an extension language, Lua has no notion of a ``main'' program:
-it only works <EM>embedded</EM> in a host client,
-called the <EM>embedding</EM> program.
-This host program can invoke functions to execute a piece of
-code in Lua, can write and read Lua variables,
+Lua is implemented as a library, written in <em>clean</em> C
+(that is, in the common subset of ANSI C and C++).
+
+<p>Being an extension language, Lua has no notion of a "main" program:
+it only works <em>embedded</em> in a host client,
+called the <em>embedding program</em> or simply the <em>host</em>.
+This host program can invoke functions to execute a piece of Lua code,
+can write and read Lua variables,
 and can register C&nbsp;functions to be called by Lua code.
 Through the use of C&nbsp;functions, Lua can be augmented to cope with
 a wide range of different domains,
 thus creating customized programming languages sharing a syntactical framework.
-<P>
-Lua is free-distribution software,
+
+<p>The Lua distribuition includes a stand-alone embedding program,
+<code>lua</code>, that uses the Lua library to offer a complete Lua interpreter.
+
+<p>Lua is free software,
 and is provided as usual with no guarantees,
 as stated in its copyright notice.
 The implementation described in this manual is available
-at the following URL's:
-<PRE>
-       <A HREF="http://www.tecgraf.puc-rio.br/lua/">http://www.tecgraf.puc-rio.br/lua/</A>
-       <A HREF="ftp://ftp.tecgraf.puc-rio.br/pub/lua/">ftp://ftp.tecgraf.puc-rio.br/pub/lua/</A>
-</PRE>
-<P>
-Like any other reference manual,
+at Lua's official web site, <code>www.lua.org</code>.
+
+<p>Like any other reference manual,
 this document is dry in places.
 For a discussion of the decisions behind the design of Lua,
 see the papers below,
-which are available at the web site above.
-<UL>
-<LI>
+which are available at Lua's web site.
+<ul>
+<li>
 R.&nbsp;Ierusalimschy, L.&nbsp;H.&nbsp;de Figueiredo, and W.&nbsp;Celes.
-Lua-an extensible extension language.
-<EM>Software: Practice &amp; Experience</EM> <B>26</B> #6 (1996) 635--652.
-<LI>
+Lua---an extensible extension language.
+<em>Software: Practice &#038; Experience</em> <b>26</b> #6 (1996) 635-652.
+<li>
 L.&nbsp;H.&nbsp;de Figueiredo, R.&nbsp;Ierusalimschy, and W.&nbsp;Celes.
 The design and implementation of a language for extending applications.
-<EM>Proceedings of XXI Brazilian Seminar on Software and Hardware</EM> (1994) 273--283.
-<LI>
+<em>Proceedings of XXI Brazilian Seminar on Software and Hardware</em> (1994) 273-283.
+<li>
 L.&nbsp;H.&nbsp;de Figueiredo, R.&nbsp;Ierusalimschy, and W.&nbsp;Celes.
 Lua: an extensible embedded language.
-<EM>Dr. Dobb's Journal</EM> <B>21</B> #12 (Dec 1996) 26--33.
-</UL>
-<P>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="2."></A>
-<H1>2 - Environment and Chunks</H1>
-<P>
-All statements in Lua are executed in a <A NAME="global environment"><EM>global environment</EM></A>.
-This environment is initialized with a call from the embedding program to
-<CODE>lua_open</CODE> and
-persists until a call to <CODE>lua_close</CODE>,
-or the end of the embedding program.
-If necessary,
-the host programmer can create multiple independent global
-environments, and freely switch between them (see Section&nbsp;<A HREF="#mangstate">5.1</A>).
-<P>
-The global environment can be manipulated by Lua code or
-by the embedding program,
-which can read and write global variables
-using API functions from the library that implements Lua.
-<P>
-<A NAME="Global variables">Global variables</A> in Lua do not need to be declared.
-Any variable is assumed to be global unless explicitly declared local
-(see Section&nbsp;<A HREF="#localvar">4.4.6</A>).
-Before the first assignment, the value of a global variable is <B>nil</B> 
-(this default can be changed; see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-A table is used to keep all global names and values
-(tables are explained in Section&nbsp;<A HREF="#TypesSec">3</A>).
-<P>
-The unit of execution of Lua is called a <A NAME="chunk"><EM>chunk</EM></A>.
-A chunk is simply a sequence of statements,
-which are executed sequentially.
-Each statement can be optionally followed by a semicolon:
-<PRE>
-       chunk ::= {stat [`<B>;</B>']}
-</PRE>
-Statements are described in Section&nbsp;<A HREF="#stats">4.4</A>.
-(The notation above is the usual extended BNF,
+<em>Dr. Dobb's Journal</em> <b>21</b> #12 (Dec 1996) 26-33.
+<li>
+R.&nbsp;Ierusalimschy, L.&nbsp;H.&nbsp;de Figueiredo, and W.&nbsp;Celes.
+The evolution of an extension language: a history of Lua,
+<em>Proceedings of V Brazilian Symposium on Programming Languages</em> (2001) B-14-B-28.
+</ul>
+
+<p>Lua means "moon" in Portuguese and is pronounced LOO-ah.
+
+<p>
+<a name="language"><h1>2 - The Language</h1></a>
+
+<p>This section describes the lexis, the syntax, and the semantics of Lua.
+In other words,
+this section describes
+which tokens are valid,
+how they can be combined,
+and what their combinations mean.
+
+<p>The language constructs will be explained using the usual extended BNF,
 in which
-{<EM>a</EM>} means 0 or more <EM>a</EM>'s,
-[<EM>a</EM>] means an optional <EM>a</EM>, and
-(<EM>a</EM>)+ means one or more <EM>a</EM>'s.
-The complete syntax of Lua is given in <A HREF="BNF">BNF</A>).
-<P>
-A chunk may be stored in a file or in a string inside the host program.
-When a chunk is executed, first it is pre-compiled into bytecodes for
-a virtual machine, and then the statements are executed in sequential order,
-by simulating the virtual machine.
-All modifications a chunk effects on the global environment persist
-after the chunk ends.
-<P>
-Chunks may also be pre-compiled into binary form and stored in files;
-see program <A NAME="luac"><TT><A HREF="luac.html">luac</A></TT></A> for details.
-Text files with chunks and their binary pre-compiled forms
-are interchangeable.
-Lua automatically detects the file type and acts accordingly.
-<A NAME="pre-compilation"></A>
-<P>
-<A NAME="TypesSec"></A>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="3."></A>
-<H1>3 - Types and Tags</H1> 
-<P>
-Lua is a <EM>dynamically typed language</EM>.
-This means that
-variables do not have types; only values do.
-Therefore, there are no type definitions in the language.
-All values carry their own type.
-Besides a type, all values also have a <A NAME="tag"><EM>tag</EM></A>.
-<P>
-There are six <A NAME="basic types">basic types</A> in Lua: <A NAME="nil"><EM>nil</EM></A>, <A NAME="number"><EM>number</EM></A>,
-<A NAME="string"><EM>string</EM></A>, <A NAME="function"><EM>function</EM></A>, <A NAME="userdata"><EM>userdata</EM></A>, and <A NAME="table"><EM>table</EM></A>.
-<EM>Nil</EM> is the type of the value <B>nil</B>,
-whose main property is to be different from any other value.
-<EM>Number</EM> represents real (double-precision floating-point) numbers,
-while <EM>string</EM> has the usual meaning.
-<A NAME="eight-bit clean"></A>
-Lua is 8-bit clean,
-and so strings may contain any 8-bit character,
-including embedded zeros (<CODE>'\0'</CODE>) (see Section&nbsp;<A HREF="#lexical">4.1</A>).
-The <CODE>type</CODE> function returns a string describing the type
-of a given value (see Section&nbsp;<A HREF="#pdf-type">6.1</A>).
-<P>
-Functions are considered <EM>first-class values</EM> in Lua.
-This means that functions can be stored in variables,
-passed as arguments to other functions, and returned as results.
-Lua can call (and manipulate) functions written in Lua and
-functions written in C.
-The two kinds of functions can be distinguished by their tags:
-all Lua functions have the same tag,
-and all C&nbsp;functions have the same tag,
-which is different from the tag of Lua functions.
-The <CODE>tag</CODE> function returns the tag
-of a given value (see Section&nbsp;<A HREF="#pdf-tag">6.1</A>).
-<P>
-The type <EM>userdata</EM> is provided to allow
-arbitrary <A NAME="C pointers">C&nbsp;pointers</A> to be stored in Lua variables.
-This type corresponds to a <CODE>void*</CODE>
-and has no pre-defined operations in Lua,
-except assignment and equality test.
-However, by using <EM>tag methods</EM>,
-the programmer can define operations for <EM>userdata</EM> values
-(see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-<P>
-The type <EM>table</EM> implements <A NAME="associative arrays">associative arrays</A>,
-that is, <A NAME="arrays">arrays</A> that can be indexed not only with numbers,
-but with any value (except <B>nil</B>).
-Therefore, this type may be used not only to represent ordinary arrays,
-but also symbol tables, sets, records, graphs, trees, etc.
-Tables are the main data structuring mechanism in Lua.
-To represent <A NAME="records">records</A>, Lua uses the field name as an index.
-The language supports this representation by
-providing <CODE>a.name</CODE> as syntactic sugar for <CODE>a["name"]</CODE>.
-Tables may also carry <EM>methods</EM>:
-Because functions are first class values,
-table fields may contain functions.
-The form <CODE>t:f(x)</CODE> is syntactic sugar for <CODE>t.f(t,x)</CODE>,
-which calls the method <CODE>f</CODE> from the table <CODE>t</CODE> passing
-the table itself as the first parameter (see Section&nbsp;<A HREF="#func-def">4.5.9</A>).
-<P>
-Note that tables are <EM>objects</EM>, and not values.
-Variables do not contain tables, only <EM>references</EM> to them.
-Assignment, parameter passing, and returns always manipulate references
-to tables, and do not imply any kind of copy.
-Moreover, tables must be explicitly created before used
-(see Section&nbsp;<A HREF="#tableconstructor">4.5.7</A>).
-<P>
-Each of the types <EM>nil</EM>, <EM>number</EM>, and <EM>string</EM> has a different tag.
-All values of each of these types have the same pre-defined tag.
-As explained above,
-values of type <EM>function</EM> can have two different tags,
-depending on whether they are Lua functions or C&nbsp;functions.
-Finally,
-values of type <EM>userdata</EM> and <EM>table</EM> can have variable tags,
-assigned by the programmer (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-The <CODE>tag</CODE> function returns the tag of a given value.
-User tags are created with the function <CODE>newtag</CODE>.
-The <CODE>settag</CODE> function
-is used to change the tag of a table (see Section&nbsp;<A HREF="#pdf-newtag">6.1</A>).
-The tag of userdata values can only be set from&nbsp;C (see Section&nbsp;<A HREF="#C-tags">5.7</A>).
-Tags are mainly used to select <EM>tag methods</EM> when
-some events occur.
-Tag methods are the main mechanism for extending the
-semantics of Lua (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-<P>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="4."></A>
-<H1>4 - The Language</H1>
-<P>
-This section describes the lexis, the syntax, and the semantics of Lua.
-<P>
-<P>
-<A NAME="lexical"></A>
-<A NAME="4.1"></A>
-<H2>4.1 - Lexical Conventions</H2> 
-<P>
-<A NAME="Identifiers"><EM>Identifiers</EM></A> in Lua can be any string of letters,
+{<em>a</em>}&nbsp;means 0 or more <em>a</em>'s, and
+[<em>a</em>]&nbsp;means an optional <em>a</em>.
+Non-terminals are shown in <em>italics</em>,
+keywords are shown in <b>bold</b>,
+and other terminal symbols are shown in <code>typewriter</code> font,
+enclosed in single quotes.
+
+<p><a name="lexical"><h2>2.1 - Lexical Conventions</h2></a>
+
+<p><em>Identifiers</em> in Lua can be any string of letters,
 digits, and underscores,
 not beginning with a digit.
-This coincides with the definition of identifiers in most languages,
-except that
-the definition of letter depends on the current locale:
-Any character considered alphabetic by the current locale
-can be used in an identifier.
-The following words are <EM>reserved</EM>, and cannot be used as identifiers:
-<A NAME="reserved words"></A>
+This coincides with the definition of identifiers in most languages.
+(The definition of letter depends on the current locale:
+any character considered alphabetic by the current locale
+can be used in an identifier.)
+
+<p>The following <em>keywords</em> are reserved
+and cannot be used as identifiers:
+
 <PRE>
        and       break     do        else      elseif
-       end       for       function  if        in
-       local     nil       not       or        repeat
-       return    then      until     while
-</PRE>
-<P>
-Lua is a case-sensitive language:
-<TT>and</TT> is a reserved word, but <TT>And</TT> and <TT>ánd</TT>
-(if the locale permits) are two different, valid identifiers.
-As a convention, identifiers starting with underscore followed by
-uppercase letters (such as <CODE>_INPUT</CODE>)
-are reserved for internal variables.
-<P>
-The following strings denote other <A NAME="tokens">tokens</A>:
-<PRE>
-       ~=    &lt;=    &gt;=    &lt;     &gt;     ==    =     +     -     *     /     
-       (     )     {     }     [     ]     ;     ,     .     ..    ...
-</PRE>
-<P>
-<A NAME="Literal strings"><EM>Literal strings</EM></A>
+       end       false     for       function  if
+       in        local     nil       not       or
+       repeat    return    then      true      until
+       while
+</PRE>
+
+<p>Lua is a case-sensitive language:
+<code>and</code> is a reserved word, but <code>And</code> and <code>AND</code>
+are two different, valid identifiers.
+As a convention, identifiers starting with an underscore followed by
+uppercase letters (such as <code>_VERSION</code>)
+are reserved for internal variables used by Lua.
+
+<p>The following strings denote other tokens:
+<PRE>
+       +     -     *     /     ^     =
+       ~=    &#060;=    >=    &#060;     >     ==
+       (     )     {     }     [     ]
+       ;     :     ,     .     ..    ...
+</PRE>
+
+<p><em>Literal strings</em>
 can be delimited by matching single or double quotes,
-and can contain the C-like escape sequences
-`<CODE>\a</CODE>' (bell),
-`<CODE>\b</CODE>' (backspace),
-`<CODE>\f</CODE>' (form feed),
-`<CODE>\n</CODE>' (newline),
-`<CODE>\r</CODE>' (carriage return),
-`<CODE>\t</CODE>' (horizontal tab),
-`<CODE>\v</CODE>' (vertical tab),
-`<CODE>\\</CODE>' (backslash),
-`<CODE>\"</CODE>' (double quote),
-`<CODE>\'</CODE>' (single quote),
-and `<CODE>\</CODE><EM>newline</EM>' (that is, a backslash followed by a real newline,
-which  results in a newline in the string).
-A character in a string may also be specified by its numerical value,
-through the escape sequence `<CODE>\</CODE><EM>ddd</EM>',
-where <EM>ddd</EM> is a sequence of up to three <EM>decimal</EM> digits.
+and can contain the following C-like escape sequences:
+<ul>
+<li><b><code>\a</code></b> --- bell
+<li><b><code>\b</code></b> --- backspace
+<li><b><code>\f</code></b> --- form feed
+<li><b><code>\n</code></b> --- newline
+<li><b><code>\r</code></b> --- carriage return
+<li><b><code>\t</code></b> --- horizontal tab
+<li><b><code>\v</code></b> --- vertical tab
+<li><b><code>\\</code></b> --- backslash
+<li><b><code>\"</code></b> --- quotation mark
+<li><b><code>\'</code></b> --- apostrophe
+<li><b><code>\[</code></b> --- left square bracket
+<li><b><code>\]</code></b> --- right square bracket
+</ul>
+Moreover, a `<code>\</code><em>newline</em>&acute;
+(that is, a backslash followed by a real newline)
+results in a newline in the string.
+A character in a string may also be specified by its numerical value
+using the escape sequence `<code>\</code><em>ddd</em>&acute;,
+where <em>ddd</em> is a sequence of up to three decimal digits.
 Strings in Lua may contain any 8-bit value, including embedded zeros,
-which can be specified as `<CODE>\000</CODE>'.
-<P>
-Literal strings can also be delimited by matching <CODE>[[</CODE> ... <CODE>]]</CODE>.
+which can be specified as `<code>\0</code>&acute;.
+
+<p>Literal strings can also be delimited by matching double square brackets
+<code>[[</code> &middot; &middot; &middot; <code>]]</code>.
 Literals in this bracketed form may run for several lines,
-may contain nested <CODE>[[</CODE> ... <CODE>]]</CODE> pairs,
-and do not interpret escape sequences.
-This form is specially convenient for
-writing strings that contain program pieces or
-other quoted strings.
-As an example, in a system using ASCII,
-the following three literals are equivalent:
-<PRE>
-       1)   "alo\n123\""
-       2)   '\97lo\10\04923"'
-       3)   [[alo
+may contain nested <code>[[</code> &middot; &middot; &middot; <code>]]</code> pairs,
+and do not interpret any escape sequences.
+For convenience,
+when the opening `<code>[[</code>&acute; is immediately followed by a newline,
+the newline is not included in the string.  
+As an example, in a system using ASCII
+(in which `<code>a</code>&acute; is coded as&nbsp;97,
+newline is coded as&nbsp;10, and `<code>1</code>&acute; is coded as&nbsp;49),
+the four literals below denote the same string:
+<PRE>
+      (1)   "alo\n123\""
+      (2)   '\97lo\10\04923"'
+      (3)   [[alo
+            123"]]
+      (4)   [[
+            alo
             123"]]
 </PRE>
-<P>
-<A NAME="Comments"><EM>Comments</EM></A> start anywhere outside a string with a
-double hyphen (<CODE>--</CODE>) and run until the end of the line.
-Moreover,
-the first line of a chunk is skipped if it starts with <CODE>#</CODE>.
-This facility allows the use of Lua as a script interpreter
-in Unix systems (see Section&nbsp;<A HREF="#lua-sa">8</A>).
-<P>
-<A NAME="Numerical constants"><EM>Numerical constants</EM></A> may be written with an optional decimal part
+
+<p><em>Numerical constants</em> may be written with an optional decimal part
 and an optional decimal exponent.
 Examples of valid numerical constants are
 <PRE>
        3     3.0     3.1416  314.16e-2   0.31416E1
 </PRE>
-<P>
-<A NAME="coercion"></A>
-<A NAME="4.2"></A>
-<H2>4.2 - Coercion</H2> 
-<P>
-Lua provides some automatic conversions between values at run time.
+
+<p><em>Comments</em> start anywhere outside a string with a
+double hyphen (<code>--</code>).
+If the text immediately after <code>--</code> is different from <code>[[</code>,
+the comment is a <em>short comment</em>,
+which runs until the end of the line.
+Otherwise, it is a <em>long comment</em>,
+which runs until the corresponding <code>]]</code>.
+Long comments may run for several lines
+and may contain nested <code>[[</code> &middot; &middot; &middot; <code>]]</code> pairs.
+
+<p>For convenience,
+the first line of a chunk is skipped if it starts with <code>#</code>.
+This facility allows the use of Lua as a script interpreter
+in Unix systems (see <a href="#lua-sa">6</a>).
+
+<p><a name="TypesSec"><h2>2.2 - Values and Types</h2></a>
+
+<p>Lua is a <em>dynamically typed language</em>.
+That means that
+variables do not have types; only values do.
+There are no type definitions in the language.
+All values carry their own type.
+
+<p>There are eight basic types in Lua:
+<em>nil</em>, <em>boolean</em>, <em>number</em>,
+<em>string</em>, <em>function</em>, <em>userdata</em>, <em>thread</em>, and <em>table</em>.
+<em>Nil</em> is the type of the value <B>nil</B>,
+whose main property is to be different from any other value;
+usually it represents the absence of a useful value.
+<em>Boolean</em> is the type of the values <B>false</B> and <B>true</B>.
+In Lua, both <B>nil</B> and <B>false</B> make a condition false;
+any other value makes it true.
+<em>Number</em> represents real (double-precision floating-point) numbers.
+(It is easy to build Lua interpreters that use other
+internal representations for numbers,
+such as single-precision float or long integers.)
+<em>String</em> represents arrays of characters.
+
+Lua is 8-bit clean:
+Strings may contain any 8-bit character,
+including embedded zeros (<code>'\0'</code>) (see <a href="#lexical">2.1</a>).
+
+<p>Functions are <em>first-class values</em> in Lua.
+That means that functions can be stored in variables,
+passed as arguments to other functions, and returned as results.
+Lua can call (and manipulate) functions written in Lua and
+functions written in C
+(see <a href="#functioncall">2.5.7</a>).
+
+<p>The type <em>userdata</em> is provided to allow arbitrary C data to
+be stored in Lua variables.
+This type corresponds to a block of raw memory
+and has no pre-defined operations in Lua,
+except assignment and identity test.
+However, by using <em>metatables</em>,
+the programmer can define operations for userdata values
+(see <a href="#metatable">2.8</a>).
+Userdata values cannot be created or modified in Lua,
+only through the C&nbsp;API.
+This guarantees the integrity of data owned by the host program.
+
+<p>The type <em>thread</em> represents independent threads of execution
+and it is used to implement coroutines.
+
+<p>The type <em>table</em> implements associative arrays,
+that is, arrays that can be indexed not only with numbers,
+but with any value (except <B>nil</B>).
+Moreover,
+tables can be <em>heterogeneous</em>,
+that is, they can contain values of all types (except <B>nil</B>).
+Tables are the sole data structuring mechanism in Lua;
+they may be used to represent ordinary arrays,
+symbol tables, sets, records, graphs, trees, etc.
+To represent records, Lua uses the field name as an index.
+The language supports this representation by
+providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>.
+There are several convenient ways to create tables in Lua
+(see <a href="#tableconstructor">2.5.6</a>).
+
+<p>Like indices,
+the value of a table field can be of any type (except <B>nil</B>).
+In particular,
+because functions are first class values,
+table fields may contain functions.
+Thus tables may also carry <em>methods</em> (see <a href="#func-def">2.5.8</a>).
+
+<p>Tables, functions, and userdata values are <em>objects</em>:
+variables do not actually <em>contain</em> these values,
+only <em>references</em> to them.
+Assignment, parameter passing, and function returns
+always manipulate references to such values;
+these operations do not imply any kind of copy.
+
+<p>The library function <code>type</code> returns a string describing the type
+of a given value (see <a href="#pdf-type">5.1</a>).
+
+<p><a name="coercion"><h3>2.2.1 - Coercion</h3></a>
+
+<p>Lua provides automatic conversion between
+string and number values at run time.
 Any arithmetic operation applied to a string tries to convert
 that string to a number, following the usual rules.
-Conversely, whenever a number is used when a string is expected,
-that number is converted to a string, in a reasonable format.
-The format is chosen so that
-a conversion from number to string then back to number
-reproduces the original number <EM>exactly</EM>.
-Thus,
-the conversion does not necessarily produces nice-looking text for some numbers.
+Conversely, whenever a number is used where a string is expected,
+the number is converted to a string, in a reasonable format.
 For complete control of how numbers are converted to strings,
-use the <CODE>format</CODE> function (see Section&nbsp;<A HREF="#format">6.2</A>).
-<P>
-<P>
-<A NAME="adjust"></A>
-<A NAME="4.3"></A>
-<H2>4.3 - Adjustment</H2> 
-<P>
-Functions in Lua can return many values.
-Because there are no type declarations,
-when a function is called
-the system does not know how many values the function will return,
-or how many parameters it needs.
-Therefore, sometimes, a list of values must be <EM>adjusted</EM>, at run time,
-to a given length.
-If there are more values than are needed,
-then the excess values are thrown away.
-If there are less values than are needed,
-then the list is extended with as many  <B>nil</B>'s as needed.
-This adjustment occurs in multiple assignments (see Section&nbsp;<A HREF="#assignment">4.4.2</A>)
-and in function calls (see Section&nbsp;<A HREF="#functioncall">4.5.8</A>).
-<P>
-<P>
-<A NAME="stats"></A>
-<A NAME="4.4"></A>
-<H2>4.4 - Statements</H2>
-<P>
-Lua supports an almost conventional set of <A NAME="statements">statements</A>,
-similar to those in Pascal or C.
-The conventional commands include
-assignment, control structures, and procedure calls.
-Non-conventional commands include table constructors
-(see Section&nbsp;<A HREF="#tableconstructor">4.5.7</A>)
-and local variable declarations (see Section&nbsp;<A HREF="#localvar">4.4.6</A>).
-<P>
-<H3>4.4.1 - Blocks</H3>
-A <A NAME="block">block</A> is a list of statements;
-syntactically, a block is equal to a chunk:
-<PRE>
-       block ::= chunk
-</PRE>
-<P>
-A block may be explicitly delimited:
+use the <code>format</code> function from the string library (see <a href="#format">5.3</a>).
+
+<p><a name="variables"><h2>2.3 - Variables</h2></a>
+
+<p>Variables are places that store values.
+
+There are three kinds of variables in Lua:
+global variables, local variables, and table fields.
+
+<p>A single name can denote a global variable or a local variable
+(or a formal parameter of a function,
+which is a particular form of local variable):
+<pre>
+	var ::= Name
+</pre>
+Variables are assumed to be global unless explicitly declared local
+(see <a href="#localvar">2.4.7</a>).
+Local variables are <em>lexically scoped</em>:
+Local variables can be freely accessed by functions
+defined inside their scope (see <a href="#visibility">2.6</a>).
+
+<p>Before the first assignment to a variable, its value is <B>nil</B>.
+
+<p>Square brackets are used to index a table:
+<pre>
+	var ::= prefixexp `<b>[</b>&acute; exp `<b>]</b>&acute;
+</pre>
+The first expression (<em>prefixexp</em>)should result in a table value;
+the second expression (<em>exp</em>)
+identifies a specific entry inside that table.
+The expression denoting the table to be indexed has a restricted syntax;
+see <a href="#expressions">2.5</a> for details.
+
+<p>The syntax <code>var.NAME</code> is just syntactic sugar for
+<code>var["NAME"]</code>:
+<pre>
+	var ::= prefixexp `<b>.</b>&acute; Name
+</pre>
+
+<p>The meaning of accesses to global variables 
+and table fields can be changed via metatables.
+An access to an indexed variable <code>t[i]</code> is equivalent to
+a call <code>gettable_event(t,i)</code>.
+(See <a href="#metatable">2.8</a> for a complete description of the
+<code>gettable_event</code> function.
+This function is not defined or callable in Lua.
+We use it here only for explanatory purposes.)
+
+<p>All global variables live as fields in ordinary Lua tables,
+called <em>environment tables</em> or simply <em>environments</em>.
+Functions written in C and exported to Lua (<em>C functions</em>)
+all share a common <em>global environment</em>.
+Each function written in Lua (a <em>Lua function</em>)
+has its own reference to an environment,
+so that all global variables in that function
+will refer to that environment table.
+When a function is created,
+it inherits the environment from the function that created it.
+To change or get the environment table of a Lua function,
+you call <code>setfenv</code> or <code>getfenv</code> (see <a href="#setfenv">5.1</a>).
+
+<p>An access to a global variable <code>x</code>
+is equivalent to <code>_env.x</code>,
+which in turn is equivalent to
 <PRE>
-       stat ::= <B>do</B> block <B>end</B>
+       gettable_event(_env, "x")
 </PRE>
+where <code>_env</code> is the environment of the running function.
+(The <code>_env</code> variable is not defined in Lua.
+We use it here only for explanatory purposes.)
+
+<p><a name="stats"><h2>2.4 - Statements</h2></a>
+
+<p>Lua supports an almost conventional set of statements,
+similar to those in Pascal or C.
+This set includes
+assignment, control structures, procedure calls,
+table constructors, and variable declarations.
+
+<p><a name="chunks"><h3>2.4.1 - Chunks</h3></a>
+
+<p>The unit of execution of Lua is called a <em>chunk</em>.
+A chunk is simply a sequence of statements,
+which are executed sequentially.
+Each statement can be optionally followed by a semicolon:
+<pre>
+	chunk ::= {stat [`<b>;</b>&acute;]}
+</pre>
+
+<p>Lua handles a chunk as the body of an anonymous function (see <a href="#func-def">2.5.8</a>).
+As such, chunks can define local variables and return values.
+
+<p>A chunk may be stored in a file or in a string inside the host program.
+When a chunk is executed, first it is pre-compiled into opcodes for
+a virtual machine,
+and then the compiled code is executed
+by an interpreter for the virtual machine.
+
+<p>Chunks may also be pre-compiled into binary form;
+see program <code>luac</code> for details.
+Programs in source and compiled forms are interchangeable;
+Lua automatically detects the file type and acts accordingly.
+
+
+<p><h3>2.4.2 - Blocks</h3>
+A block is a list of statements;
+syntactically, a block is equal to a chunk:
+<pre>
+	block ::= chunk
+</pre>
+
+<p>A block may be explicitly delimited to produce a single statement:
+<pre>
+	stat ::= <b>do</b> block <b>end</b>
+</pre>
 Explicit blocks are useful
-to control the scope of local variables (see Section&nbsp;<A HREF="#localvar">4.4.6</A>).
+to control the scope of variable declarations.
 Explicit blocks are also sometimes used to
-add a <B>return</B> or <B>break</B> statement in the middle
-of another block (see Section&nbsp;<A HREF="#control">4.4.3</A>).
-<P>
-<A NAME="assignment"></A>
-<H3>4.4.2 - <A NAME="Assignment</H3>">Assignment</H3></A> 
-Lua allows <A NAME="multiple assignment">multiple assignment</A>.
+add a <b>return</b> or <b>break</b> statement in the middle
+of another block (see <a href="#control">2.4.4</a>).
+
+
+<p><a name="assignment"><h3>2.4.3 - Assignment</h3></a>
+
+<p>Lua allows multiple assignment.
 Therefore, the syntax for assignment
 defines a list of variables on the left side
 and a list of expressions on the right side.
 The elements in both lists are separated by commas:
-<PRE>
-       stat ::= varlist1 `<B>=</B>' explist1
-       varlist1 ::= var {`<B>,</B>' var}
-</PRE>
-This statement first evaluates all values on the right side
-and eventual indices on the left side,
-and then makes the assignments.
-So, the code
+<pre>
+	stat ::= varlist1 `<b>=</b>&acute; explist1
+	varlist1 ::= var {`<b>,</b>&acute; var}
+	explist1 ::= exp {`<b>,</b>&acute; exp}
+</pre>
+Expressions are discussed in <a href="#expressions">2.5</a>.
+
+<p>Before the assignment,
+the list of values is <em>adjusted</em> to the length of
+the list of variables.
+If there are more values than needed,
+the excess values are thrown away.
+If there are fewer values than needed,
+the list is extended with as many  <B>nil</B>'s as needed.
+If the list of expressions ends with a function call,
+then all values returned by that function call enter in the list of values,
+before the adjustment
+(except when the call is enclosed in parentheses; see <a href="#expressions">2.5</a>).
+
+<p>The assignment statement first evaluates all its expressions
+and only then are the assignments performed.
+Thus the code
 <PRE>
        i = 3
-       i, a[i] = 4, 20
+       i, a[i] = i+1, 20
 </PRE>
-sets <CODE>a[3]</CODE> to 20, but does not affect <CODE>a[4]</CODE>
-because the <CODE>i</CODE> in <CODE>a[i]</CODE> is evaluated
-before it is assigned <CODE>4</CODE>.
-<P>
-Multiple assignment can be used to exchange two values, as in
+sets <code>a[3]</code> to 20, without affecting <code>a[4]</code>
+because the <code>i</code> in <code>a[i]</code> is evaluated (to 3)
+before it is assigned 4.
+Similarly, the line
 <PRE>
        x, y = y, x
 </PRE>
-<P>
-The two lists in a multiple assignment may have different lengths.
-Before the assignment, the list of values is adjusted to
-the length of the list of variables (see Section&nbsp;<A HREF="#adjust">4.3</A>).
-<P>
-A single name can denote a global variable, a local variable,
-or a formal parameter:
-<PRE>
-       var ::= name
-</PRE>
-<P>
-Square brackets are used to index a table:
-<PRE>
-       var ::= varorfunc `<B>[</B>' exp1 `<B>]</B>'
-       varorfunc ::= var | functioncall
-</PRE>
-The <EM>varorfunc</EM> should result in a table value,
-from where the field indexed by the expression <EM>exp1</EM>
-value gets the assigned value.
-<P>
-The syntax <CODE>var.NAME</CODE> is just syntactic sugar for
-<CODE>var["NAME"]</CODE>:
-<PRE>
-       var ::= varorfunc `<B>.</B>' name
-</PRE>
-<P>
-The meaning of assignments and evaluations of global variables and
-indexed variables can be changed by tag methods (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-Actually,
-an assignment <CODE>x = val</CODE>, where <CODE>x</CODE> is a global variable,
-is equivalent to a call <CODE>setglobal("x", val)</CODE> and
-an assignment <CODE>t[i] = val</CODE> is equivalent to
-<CODE>settable_event(t,i,val)</CODE>.
-See Section&nbsp;<A HREF="#tag-method">4.8</A> for a complete description of these functions
-(<CODE>setglobal</CODE> is in the basic library;
-<TT>settable_event</TT> is used for explanatory purposes only).
-<P>
-<A NAME="control"></A>
-<H3>4.4.3 - Control Structures</H3>
-The control structures
-<B>if</B>, <B>while</B>, and <B>repeat</B> have the usual meaning and
-familiar syntax
-<A NAME="while-do statement"></A>
-<A NAME="repeat-until statement"></A>
-<A NAME="if-then-else statement"></A>
-<PRE>
-       stat ::= <B>while</B> exp1 <B>do</B> block <B>end</B>
-       stat ::= <B>repeat</B> block <B>until</B> exp1
-       stat ::= <B>if</B> exp1 <B>then</B> block {<B>elseif</B> exp1 <B>then</B> block} [<B>else</B> block] <B>end</B>
-</PRE>
-The <A NAME="condition expression">condition expression</A> <EM>exp1</EM> of a control structure may return any value.
-All values different from <B>nil</B> are considered true;
-only <B>nil</B> is considered false.
-<P>
-The <B>return</B> statement is used to return values
-from a function or from a chunk.
-<A NAME="return"></A>
+exchanges the values of <code>x</code> and <code>y</code>.
 
-<A NAME="return statement"></A>
-Because functions or chunks may return more than one value,
-the syntax for the <B>return</B> statement is
-<PRE>
-       stat ::= <B>return</B> [explist1]
-</PRE>
-<P>
-The <B>break</B> statement can be used to terminate the execution of a loop,
-skipping to the next statement after the loop:
-<A NAME="break statement"></A>
+<p>The meaning of assignments to global variables
+and table fields can be changed via metatables.
+An assignment to an indexed variable <code>t[i] = val</code> is equivalent to
+<code>settable_event(t,i,val)</code>.
+(See <a href="#metatable">2.8</a> for a complete description of the
+<code>settable_event</code> function.
+This function is not defined or callable in Lua.
+We use it here only for explanatory purposes.)
+
+<p>An assignment to a global variable <code>x = val</code>
+is equivalent to the assignment
+<code>_env.x = val</code>,
+which in turn is equivalent to
 <PRE>
-       stat ::= <B>break</B>
+       settable_event(_env, "x", val)
 </PRE>
-A <B>break</B> ends the innermost enclosing loop
-(<B>while</B>, <B>repeat</B>, or <B>for</B>).
-<P>
-For syntactic reasons, <B>return</B> and <B>break</B>
-statements can only be written as the <EM>last</EM> statements of a block.
-If it is really necessary to <B>return</B> or <B>break</B> in the
+where <code>_env</code> is the environment of the running function.
+(The <code>_env</code> variable is not defined in Lua.
+We use it here only for explanatory purposes.)
+
+<p><a name="control"><h3>2.4.4 - Control Structures</h3></a>
+The control structures
+<b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
+familiar syntax:
+
+
+
+<pre>
+	stat ::= <b>while</b> exp <b>do</b> block <b>end</b>
+	stat ::= <b>repeat</b> block <b>until</b> exp
+	stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b>
+</pre>
+Lua also has a <b>for</b> statement, in two flavors (see <a href="#for">2.4.5</a>).
+
+<p>The condition expression <em>exp</em> of a
+control structure may return any value.
+Both <B>false</B> and <B>nil</B> are considered false.
+All values different from <B>nil</B> and <B>false</B> are considered true
+(in particular, the number 0 and the empty string are also true).
+
+<p>The <b>return</b> statement is used to return values
+from a function or from a chunk.
+
+Functions and chunks may return more than one value,
+so the syntax for the <b>return</b> statement is
+<pre>
+	stat ::= <b>return</b> [explist1]
+</pre>
+
+<p>The <b>break</b> statement can be used to terminate the execution of a
+<b>while</b>, <b>repeat</b>, or <b>for</b> loop,
+skiping to the next statement after the loop:
+
+<pre>
+	stat ::= <b>break</b>
+</pre>
+A <b>break</b> ends the innermost enclosing loop.
+
+<p>For syntactic reasons, <b>return</b> and <b>break</b>
+statements can only be written as the <em>last</em> statement of a block.
+If it is really necessary to <b>return</b> or <b>break</b> in the
 middle of a block,
-an explicit inner block can used,
-as in the idiom `<CODE>do return end</CODE>',
-because now <B>return</B> is last statement in the inner block.
-<P>
-<A NAME="for"></A>
-<H3>4.4.4 - For Statement</H3> <A NAME="for statement"></A>
-<P>
-The <B>for</B> statement has two forms,
-one for numbers and one for tables.
-The numerical <B>for</B> loop has the following syntax:
-<PRE>
-       stat ::= <B>for</B> name `<B>=</B>' exp1 `<B>,</B>' exp1 [`<B>,</B>' exp1] <B>do</B> block <B>end</B>
-</PRE>
-A <B>for</B> statement like
+then an explicit inner block can be used,
+as in the idioms
+`<code>do return end</code>&acute; and
+`<code>do break end</code>&acute;,
+because now <b>return</b> and <b>break</b> are the last statements in
+their (inner) blocks.
+In practice,
+those idioms are only used during debugging.
+
+<p><a name="for"><h3>2.4.5 - For Statement</h3></a>
+
+<p>The <b>for</b> statement has two forms:
+one numeric and one generic.
+
+
+<p>The numeric <b>for</b> loop repeats a block of code while a
+control variable runs through an arithmetic progression.
+It has the following syntax:
+<pre>
+	stat ::= <b>for</b> Name `<b>=</b>&acute; exp `<b>,</b>&acute; exp [`<b>,</b>&acute; exp] <b>do</b> block <b>end</b>
+</pre>
+The <em>block</em> is repeated for <em>name</em> starting at the value of
+the first <em>exp</em>, until it passes the second <em>exp</em> by steps of the
+third <em>exp</em>.
+More precisely, a <b>for</b> statement like
 <PRE>
-       for var = e1 ,e2, e3 do block end
+       for var = e1, e2, e3 do block end
 </PRE>
 is equivalent to the code:
 <PRE>
        do
          local var, _limit, _step = tonumber(e1), tonumber(e2), tonumber(e3)
          if not (var and _limit and _step) then error() end
-         while (_step&gt;0 and var&lt;=_limit) or (_step&lt;=0 and var&gt;=_limit) do
+         while (_step>0 and var&#060;=_limit) or (_step&#060;=0 and var>=_limit) do
            block
-           var = var+_step
+           var = var + _step
          end
        end
 </PRE>
 Note the following:
-<UL><LI>sep=0pt
-<LI><CODE>_limit</CODE> and <CODE>_step</CODE> are invisible variables.
+<ul>
+<li> All three control expressions are evaluated only once,
+before the loop starts.
+They must all result in numbers.
+<li> <code>_limit</code> and <code>_step</code> are invisible variables.
 The names are here for explanatory purposes only.
-<LI>The behavior is <EM>undefined</EM> if you assign to <CODE>var</CODE> inside
+<li> The behavior is <em>undefined</em> if you assign to <code>var</code> inside
 the block.
-<LI>If the third expression (the step) is absent, then a step of&nbsp;1 is used.
-<LI>Both the limit and the step are evaluated only once,
-before the loop starts.
-<LI>The variable <CODE>var</CODE> is local to the statement;
-you cannot use its value after the <B>for</B> ends.
-<LI>You can use <B>break</B> to exit a <B>for</B>.
-If you need the value of the index,
-assign it to another variable before breaking.
-</UL>
-<P>
-The table <B>for</B> statement traverses all pairs
-(index,value) of a given table.
-It has the following syntax:
-<PRE>
-       stat ::= <B>for</B> name `<B>,</B>' name <B>in</B> exp1 <B>do</B> block <B>end</B>
-</PRE>
-A <B>for</B> statement like
-<PRE>
-       for index, value in exp do block end
+<li> If the third expression (the step) is absent, then a step of&nbsp;1 is used.
+<li> You can use <b>break</b> to exit a <b>for</b> loop.
+<li> The loop variable <code>var</code> is local to the statement;
+you cannot use its value after the <b>for</b> ends or is broken.
+If you need the value of the loop variable <code>var</code>,
+then assign it to another variable before breaking or exiting the loop.
+</ul>
+
+<p>The generic <b>for</b> statement works over functions,
+called <em>iterators</em>.
+For each iteration, it calls its iterator function to produce a new value,
+stopping when the new value is <B>nil</B>.
+The generic <b>for</b> loop has the following syntax:
+<pre>
+	stat ::= <b>for</b> Name {`<b>,</b>&acute; Name} <b>in</b> explist1 <b>do</b> block <b>end</b>
+</pre>
+A <b>for</b> statement like
+<PRE>
+       for var_1, ..., var_n in explist do block end
 </PRE>
 is equivalent to the code:
 <PRE>
        do
-         local _t = exp
-         local index, value = next(t, nil)
-         while index do
+         local _f, _s, var_1 = explist
+         local var_2, ... , var_n
+         while true do
+           var_1, ..., var_n = _f(_s, var_1)
+           if var_1 == nil then break end
            block
-           index, value = next(t, index)
          end
        end
 </PRE>
 Note the following:
-<UL><LI>sep=0pt
-<LI><CODE>_t</CODE> is an invisible variable.
-The name is here for explanatory purposes only.
-<LI>The behavior is <EM>undefined</EM> if you assign to <CODE>index</CODE> inside
-the block.
-<LI>The behavior is <EM>undefined</EM> if you change
-the table <CODE>_t</CODE> during the traversal.
-<LI>The variables <CODE>index</CODE> and <CODE>value</CODE> are local to the statement;
-you cannot use their values after the <B>for</B> ends.
-<LI>You can use <B>break</B> to exit a <B>for</B>.
-If you need the value of <CODE>index</CODE> or <CODE>value</CODE>,
-assign them to other variables before breaking.
-<LI>The order that table elements are traversed is undefined,
-<EM>even for numerical indices</EM>.
-If you want to traverse indices in numerical order,
-use a numerical <B>for</B>.
-</UL>
-<P>
-<P>
-<A NAME="funcstat"></A>
-<H3>4.4.5 - Function Calls as Statements</H3> 
-Because of possible side-effects,
+<ul>
+<li> <code>explist</code> is evaluated only once.
+Its results are an <em>iterator</em> function,
+a <em>state</em>, and an initial value for the first <em>iterator variable</em>.
+<li> <code>_f</code> and <code>_s</code> are invisible variables.
+The names are here for explanatory purposes only.
+<li> The behavior is <em>undefined</em> if you assign to
+<code>var_1</code> inside the block.
+<li> You can use <b>break</b> to exit a <b>for</b> loop.
+<li> The loop variables <code>var_i</code> are local to the statement;
+you cannot use their values after the <b>for</b> ends.
+If you need these values,
+then assign them to other variables before breaking or exiting the loop.
+</ul>
+
+<p><a name="funcstat"><h3>2.4.6 - Function Calls as Statements</h3></a>
+To allow possible side-effects,
 function calls can be executed as statements:
-<PRE>
-       stat ::= functioncall
-</PRE>
+<pre>
+	stat ::= functioncall
+</pre>
 In this case, all returned values are thrown away.
-Function calls are explained in Section&nbsp;<A HREF="#functioncall">4.5.8</A>.
-<P>
-<A NAME="localvar"></A>
-<H3>4.4.6 - Local Declarations</H3> 
-<A NAME="Local variables">Local variables</A> may be declared anywhere inside a block.
+Function calls are explained in <a href="#functioncall">2.5.7</a>.
+
+<p><a name="localvar"><h3>2.4.7 - Local Declarations</h3></a>
+Local variables may be declared anywhere inside a block.
 The declaration may include an initial assignment:
-<PRE>
-       stat ::= <B>local</B> declist [init]
-       declist ::= name {`<B>,</B>' name}
-       init ::= `<B>=</B>' explist1
-</PRE>
+<pre>
+	stat ::= <b>local</b> namelist [`<b>=</b>&acute; explist1]
+	namelist ::= Name {`<b>,</b>&acute; Name}
+</pre>
 If present, an initial assignment has the same semantics
-of a multiple assignment.
+of a multiple assignment (see <a href="#assignment">2.4.3</a>).
 Otherwise, all variables are initialized with <B>nil</B>.
-<P>
-A chunk is also a block,
-and so local variables can be declared outside any explicit block.
-<P>
-The scope of local variables begins <EM>after</EM>
-the declaration and lasts until the end of the block.
-Thus, the code
-<CODE>local print=print</CODE>
-creates a local variable called <CODE>print</CODE> whose
-initial value is that of the <EM>global</EM> variable of the same name.
-<P>
-<P>
-<A NAME="4.5"></A>
-<H2>4.5 - Expressions</H2>
-<P>
-<H3>4.5.1 - <A NAME="Basic Expressions</H3>">Basic Expressions</H3></A>
-The basic expressions in Lua are
-<PRE>
-       exp ::= `<B>(</B>' exp `<B>)</B>'
-       exp ::= <B>nil</B>
-       exp ::= number
-       exp ::= literal
-       exp ::= var
-       exp ::= upvalue
-       exp ::= function
-       exp ::= functioncall
-       exp ::= tableconstructor
-</PRE>
-<P>
-Numbers (numerical constants) and
-literal strings are explained in Section&nbsp;<A HREF="#lexical">4.1</A>;
-variables are explained in Section&nbsp;<A HREF="#assignment">4.4.2</A>;
-upvalues are explained in Section&nbsp;<A HREF="#upvalue">4.6</A>;
-function definitions are explained in Section&nbsp;<A HREF="#func-def">4.5.9</A>;
-function calls are explained in Section&nbsp;<A HREF="#functioncall">4.5.8</A>.
-Table constructors are explained in Section&nbsp;<A HREF="#tableconstructor">4.5.7</A>.
-<P>
-An access to a global variable <CODE>x</CODE> is equivalent to a
-call <CODE>getglobal("x")</CODE> and
-an access to an indexed variable <CODE>t[i]</CODE> is equivalent to
-a call <CODE>gettable_event(t,i)</CODE>.
-See Section&nbsp;<A HREF="#tag-method">4.8</A> for a description of these functions
-(<CODE>getglobal</CODE> is in the basic library;
-<TT>gettable_event</TT> is used for explanatory purposes only).
-<P>
-The non-terminal <EM>exp1</EM> is used to indicate that the values
-returned by an expression must be adjusted to one single value:
-<PRE>
-       exp1 ::= exp
-</PRE>
-<P>
-<H3>4.5.2 - Arithmetic Operators</H3>
-Lua supports the usual <A NAME="arithmetic operators">arithmetic operators</A>:
-the binary <CODE>+</CODE> (addition),
-<CODE>-</CODE> (subtraction), <CODE>*</CODE> (multiplication),
-<CODE>/</CODE> (division), and <CODE>^</CODE> (exponentiation);
-and unary <CODE>-</CODE> (negation).
+
+<p>A chunk is also a block (see <a href="#chunks">2.4.1</a>),
+so local variables can be declared in a chunk outside any explicit block.
+Such local variables die when the chunk ends.
+
+<p>The visibility rules for local variables are explained in <a href="#visibility">2.6</a>.
+
+<p><a name="expressions"><h2>2.5 - Expressions</h2></a>
+
+<p>
+The basic expressions in Lua are the following:
+<pre>
+	exp ::= prefixexp
+	exp ::= <b>nil</b> | <b>false</b> | <b>true</b>
+	exp ::= Number
+	exp ::= Literal
+	exp ::= function
+	exp ::= tableconstructor
+	prefixexp ::= var | functioncall | `<b>(</b>&acute; exp `<b>)</b>&acute;
+</pre>
+
+<p>Numbers and literal strings are explained in <a href="#lexical">2.1</a>;
+variables are explained in <a href="#variables">2.3</a>;
+function definitions are explained in <a href="#func-def">2.5.8</a>;
+function calls are explained in <a href="#functioncall">2.5.7</a>;
+table constructors are explained in <a href="#tableconstructor">2.5.6</a>.
+
+
+<p>An expression enclosed in parentheses always results in only one value.
+Thus,
+<code>(f(x,y,z))</code> is always a single value,
+even if <code>f</code> returns several values.
+(The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code>
+or <B>nil</B> if <code>f</code> does not return any values.)
+
+<p>Expressions can also be built with arithmetic operators, relational operators,
+and logical operators, all of which are explained below.
+
+<p><h3>2.5.1 - Arithmetic Operators</h3>
+Lua supports the usual arithmetic operators:
+the binary <code>+</code> (addition),
+<code>-</code> (subtraction), <code>*</code> (multiplication),
+<code>/</code> (division), and <code>^</code> (exponentiation);
+and unary <code>-</code> (negation).
 If the operands are numbers, or strings that can be converted to
-numbers (according to the rules given in Section&nbsp;<A HREF="#coercion">4.2</A>),
+numbers (see <a href="#coercion">2.2.1</a>),
 then all operations except exponentiation have the usual meaning.
-Otherwise, an appropriate tag method is called (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-An exponentiation always calls a tag method.
-The standard mathematical library redefines this method for numbers,
-giving the expected meaning to <A NAME="exponentiation">exponentiation</A>
-(see Section&nbsp;<A HREF="#mathlib">6.3</A>).
-<P>
-<H3>4.5.3 - Relational Operators</H3>
-The <A NAME="relational operators">relational operators</A> in Lua are
-<PRE>
-       ==    ~=    &lt;     &gt;     &lt;=    &gt;=
-</PRE>
-These operators return <B>nil</B> as false and a value different from <B>nil</B> as true.
-<P>
-Equality (<CODE>==</CODE>) first compares the tags of its operands.
-If they are different, then the result is <B>nil</B>.
-Otherwise, their values are compared.
+Exponentiation calls a global function <code>__pow</code>;
+otherwise, an appropriate metamethod is called (see <a href="#metatable">2.8</a>).
+The standard mathematical library defines function <code>__pow</code>,
+giving the expected meaning to exponentiation
+(see <a href="#mathlib">5.5</a>).
+
+<p><a name="rel-ops"><h3>2.5.2 - Relational Operators</h3></a>
+The relational operators in Lua are
+<PRE>
+       ==    ~=    &#060;     >     &#060;=    >=
+</PRE>
+These operators always result in <B>false</B> or <B>true</B>.
+
+<p>Equality (<code>==</code>) first compares the type of its operands.
+If the types are different, then the result is <B>false</B>.
+Otherwise, the values of the operands are compared.
 Numbers and strings are compared in the usual way.
-Tables, userdata, and functions are compared by reference,
-that is, two tables are considered equal only if they are the <EM>same</EM> table.
-The operator <CODE>~=</CODE> is exactly the negation of equality (<CODE>==</CODE>).
-<P>
-The conversion rules of Section&nbsp;<A HREF="#coercion">4.2</A>
-<EM>do not</EM> apply to equality comparisons.
-Thus, <CODE>"0"==0</CODE> evaluates to <EM>false</EM>,
-and <CODE>t[0]</CODE> and <CODE>t["0"]</CODE> denote different
+Objects (tables, userdata, threads, and functions)
+are compared by <em>reference</em>:
+Two objects are considered equal only if they are the <em>same</em> object.
+Every time you create a new object (a table, userdata, or function),
+this new object is different from any previously existing object.
+
+<p>You can change the way that Lua compares tables and userdata 
+using the "eq" metamethod (see <a href="#metatable">2.8</a>).
+
+<p>The conversion rules of <a href="#coercion">2.2.1</a>
+<em>do not</em> apply to equality comparisons.
+Thus, <code>"0"==0</code> evaluates to <B>false</B>,
+and <code>t[0]</code> and <code>t["0"]</code> denote different
 entries in a table.
-<P>
-The order operators work as follows.
+
+
+<p>The operator <code>~=</code> is exactly the negation of equality (<code>==</code>).
+
+<p>The order operators work as follows.
 If both arguments are numbers, then they are compared as such.
 Otherwise, if both arguments are strings,
-then their values are compared using lexicographical order.
-Otherwise, the ``lt'' tag method is called (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-<P>
-<H3>4.5.4 - Logical Operators</H3>
-The <A NAME="logical operators">logical operators</A> in Lua are
-<A NAME="and"></A><A NAME="or"></A><A NAME="not"></A>
+then their values are compared according to the current locale.
+Otherwise, Lua tries to call the "lt" or the "le"
+metamethod (see <a href="#metatable">2.8</a>).
+
+<p><h3>2.5.3 - Logical Operators</h3>
+The logical operators in Lua are
+
 <PRE>
        and   or    not
 </PRE>
-Like the control structures, all logical operators
-consider <B>nil</B> as false and anything else as true.
-<P>
-The conjunction operator <CODE>and</CODE> returns <B>nil</B> if its first argument is <B>nil</B>;
-otherwise, it returns its second argument.
-The disjunction operator <CODE>or</CODE> returns its first argument
-if it is different from <B>nil</B>;
-otherwise, it returns its second argument.
-Both <CODE>and</CODE> and <CODE>or</CODE> use <A NAME="short-cut evaluation">short-cut evaluation</A>,
+Like the control structures (see <a href="#control">2.4.4</a>),
+all logical operators consider both <B>false</B> and <B>nil</B> as false
+and anything else as true.
+
+
+<p>The operator <b>not</b> always return <B>false</B> or <B>true</B>.
+
+<p>The conjunction operator <b>and</b> returns its first argument
+if this value is <B>false</B> or <B>nil</B>;
+otherwise, <b>and</b> returns its second argument.
+The disjunction operator <b>or</b> returns its first argument
+if this value is different from <B>nil</B> and <B>false</B>;
+otherwise, <b>or</b> returns its second argument.
+Both <b>and</b> and <b>or</b> use short-cut evaluation,
 that is,
 the second operand is evaluated only if necessary.
-<P>
-There are two useful Lua idioms that use logical operators.
-The first idiom is
-<PRE>
-       x = x or v
-</PRE>
-which is equivalent to
-<PRE>
-       if x == nil then x = v end
-</PRE>
-This idiom sets <CODE>x</CODE> to a default value <CODE>v</CODE> when <CODE>x</CODE> is not set.
-<P>
-The second idiom is
-<PRE>
-       x = a and b or c
-</PRE>
-which should be read as <CODE>x = (a and b) or c</CODE>.
-This idiom is equivalent to
+For example,
 <PRE>
-       if a then x = b else x = c end
+       10 or error()       -> 10
+       nil or "a"          -> "a"
+       nil and 10          -> nil
+       false and error()   -> false
+       false and nil       -> false
+       false or nil        -> nil
+       10 and 20           -> 20
 </PRE>
-provided that <CODE>b</CODE> is not <B>nil</B>.
-<P>
-<A NAME="concat"></A>
-<H3>4.5.5 - Concatenation</H3> 
-The string <A NAME="concatenation">concatenation</A> operator in Lua is
-denoted by two dots (`<A NAME=".."><TT>..</TT></A>').
+
+<p><a name="concat"><h3>2.5.4 - Concatenation</h3></a>
+The string concatenation operator in Lua is
+denoted by two dots (`<code>..</code>&acute;).
 If both operands are strings or numbers, then they are converted to
-strings according to the rules in Section&nbsp;<A HREF="#coercion">4.2</A>.
-Otherwise, the ``concat'' tag method is called (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-<P>
-<H3>4.5.6 - Precedence</H3>
-<A NAME="Operator precedence">Operator precedence</A> in Lua follows the table below,
-from the lower to the higher priority:
-<PRE>
-       and   or
-       &lt;     &gt;     &lt;=    &gt;=    ~=    ==
+strings according to the rules mentioned in <a href="#coercion">2.2.1</a>.
+Otherwise, the "concat" metamethod is called (see <a href="#metatable">2.8</a>).
+
+<p><h3>2.5.5 - Precedence</h3>
+Operator precedence in Lua follows the table below,
+from lower to higher priority:
+<PRE>
+       or
+       and
+       &#060;     >     &#060;=    >=    ~=    ==
        ..
        +     -
        *     /
        not   - (unary)
        ^
 </PRE>
-All binary operators are left associative,
-except for <CODE>^</CODE> (exponentiation),
-which is right associative.
-The pre-compiler may rearrange the order of evaluation of
-associative operators (such as&nbsp;<CODE>..</CODE> or&nbsp;<CODE>+</CODE>),
-as long as these optimizations do not change normal results.
-However, these optimizations may change some results
-if you define non-associative
-tag methods for these operators.
-<P>
-<A NAME="tableconstructor"></A>
-<H3>4.5.7 - Table Constructors</H3> 
-Table <A NAME="constructors">constructors</A> are expressions that create tables;
-every time a constructor is evaluated, a new table is created.
+As usual, you can use parentheses to change the precedences of an expression.
+The concatenation (`<code>..</code>&acute;) and exponentiation (`<code>^</code>&acute;)
+operators are right associative.
+All other binary operators are left associative.
+
+<p><a name="tableconstructor"><h3>2.5.6 - Table Constructors</h3></a>
+Table constructors are expressions that create tables.
+Every time a constructor is evaluated, a new table is created.
 Constructors can be used to create empty tables,
 or to create a table and initialize some of its fields.
 The general syntax for constructors is
-<PRE>
-       tableconstructor ::= `<B>{</B>' fieldlist `<B>}</B>'
-       fieldlist ::= lfieldlist | ffieldlist | lfieldlist `<B>;</B>' ffieldlist | ffieldlist `<B>;</B>' lfieldlist
-       lfieldlist ::= [lfieldlist1]
-       ffieldlist ::= [ffieldlist1]
-</PRE>
-<P>
-The form <EM>lfieldlist1</EM> is used to initialize lists:
-<PRE>
-       lfieldlist1 ::= exp {`<B>,</B>' exp} [`<B>,</B>']
-</PRE>
-The expressions in the list are assigned to consecutive numerical indices,
-starting with&nbsp;1.
-For example,
-<PRE>
-       a = {"v1", "v2", 34}
-</PRE>
-is equivalent to
-<PRE>
-       do
-         local temp = {}
-         temp[1] = "v1"
-         temp[2] = "v2"
-         temp[3] = 34
-         a = temp
-       end
-</PRE>
-<P>
-The form <EM>ffieldlist1</EM> initializes other fields in a table:
-<PRE>
-       ffieldlist1 ::= ffield {`<B>,</B>' ffield} [`<B>,</B>']
-       ffield ::= `<B>[</B>' exp `<B>]</B>' `<B>=</B>' exp | name `<B>=</B>' exp
-</PRE>
+<pre>
+	tableconstructor ::= `<b>{</b>&acute; [fieldlist] `<b>}</b>&acute;
+	fieldlist ::= field {fieldsep field} [fieldsep]
+	field ::= `<b>[</b>&acute; exp `<b>]</b>&acute; `<b>=</b>&acute; exp | Name `<b>=</b>&acute; exp | exp
+	fieldsep ::= `<b>,</b>&acute; | `<b>;</b>&acute;
+</pre>
+
+<p>Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry
+with key <code>exp1</code> and value <code>exp2</code>.
+A field of the form <code>name = exp</code> is equivalent to
+<code>["name"] = exp</code>.
+Finally, fields of the form <code>exp</code> are equivalent to
+<code>[i] = exp</code>, where <code>i</code> are consecutive numerical integers,
+starting with 1.
+Fields in the other formats do not affect this counting.
 For example,
 <PRE>
-       a = {[f(k)] = g(y), x = 1, y = 3, [0] = b+c}
+       a = {[f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45}
 </PRE>
 is equivalent to
 <PRE>
        do
          local temp = {}
-         temp[f(k)] = g(y)
-         temp.x = 1    -- or temp["x"] = 1
-         temp.y = 3    -- or temp["y"] = 3
-         temp[0] = b+c
+         temp[f(1)] = g
+         temp[1] = "x"         -- 1st exp
+         temp[2] = "y"         -- 2nd exp
+         temp.x = 1            -- temp["x"] = 1
+         temp[3] = f(x)        -- 3rd exp
+         temp[30] = 23
+         temp[4] = 45          -- 4th exp
          a = temp
        end
 </PRE>
-An expression like <CODE>{x = 1, y = 4}</CODE> is
-in fact syntactic sugar for <CODE>{["x"] = 1, ["y"] = 4}</CODE>.
-<P>
-Both forms may have an optional trailing comma,
-and can be used in the same constructor separated by
-a semi-colon.
-For example, all forms below are correct.
-<PRE>
-       x = {;}
-       x = {"a", "b",}
-       x = {type="list"; "a", "b"}
-       x = {f(0), f(1), f(2),; n=3,}
-</PRE>
-<P>
-<A NAME="functioncall"></A>
-<H3>4.5.8 - Function Calls</H3>  
-A <A NAME="function call">function call</A> in Lua has the following syntax:
-<PRE>
-       functioncall ::= varorfunc args
-</PRE>
-First, <EM>varorfunc</EM> is evaluated.
-If its value has type <EM>function</EM>,
-then this function is called,
+
+<p>If the last field in the list has the form <code>exp</code>
+and the expression is a function call,
+then all values returned by the call enter the list consecutively
+(see <a href="#functioncall">2.5.7</a>).
+To avoid this,
+enclose the function call in parentheses (see <a href="#expressions">2.5</a>).
+
+<p>The field list may have an optional trailing separator,
+as a convenience for machine-generated code.
+
+<p><a name="functioncall"><h3>2.5.7 - Function Calls</h3></a>
+A function call in Lua has the following syntax:
+<pre>
+	functioncall ::= prefixexp args
+</pre>
+In a function call,
+first <em>prefixexp</em> and <em>args</em> are evaluated.
+If the value of <em>prefixexp</em> has type <em>function</em>,
+then that function is called
 with the given arguments.
-Otherwise, the ``function'' tag method is called,
-having as first parameter the value of <EM>varorfunc</EM>,
-and then the original call arguments
-(see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-<P>
-The form
-<PRE>
-       functioncall ::= varorfunc `<B>:</B>' name args
-</PRE>
-can be used to call ``methods''.
-A call <CODE>v:name(...)</CODE>
-is syntactic sugar for <CODE>v.name(v, ...)</CODE>,
-except that <CODE>v</CODE> is evaluated only once.
-<P>
-Arguments have the following syntax:
-<PRE>
-       args ::= `<B>(</B>' [explist1] `<B>)</B>'
-       args ::= tableconstructor
-       args ::= literal
-       explist1 ::= {exp1 `<B>,</B>'} exp
-</PRE>
+Otherwise, its "call" metamethod is called,
+having as first parameter the value of <em>prefixexp</em>,
+followed by the original call arguments
+(see <a href="#metatable">2.8</a>).
+
+<p>The form
+<pre>
+	functioncall ::= prefixexp `<b>:</b>&acute; Name args
+</pre>
+can be used to call "methods".
+A call <code>v:name(...)</code>
+is syntactic sugar for <code>v.name(v,...)</code>,
+except that <code>v</code> is evaluated only once.
+
+<p>Arguments have the following syntax:
+<pre>
+	args ::= `<b>(</b>&acute; [explist1] `<b>)</b>&acute;
+	args ::= tableconstructor
+	args ::= Literal
+</pre>
 All argument expressions are evaluated before the call.
-A call of the form <CODE>f{...}</CODE> is syntactic sugar for
-<CODE>f({...})</CODE>, that is,
+A call of the form <code>f{...}</code> is syntactic sugar for
+<code>f({...})</code>, that is,
 the argument list is a single new table.
-A call of the form <CODE>f'...'</CODE>
-(or <CODE>f"..."</CODE> or <CODE>f[[...]]</CODE>) is syntactic sugar for
-<CODE>f('...')</CODE>, that is,
+A call of the form <code>f'...'</code>
+(or <code>f"..."</code> or <code>f[[...]]</code>) is syntactic sugar for
+<code>f('...')</code>, that is,
 the argument list is a single literal string.
-<P>
-Because a function can return any number of results
-(see Section&nbsp;<A HREF="#return">4.4.3</A>),
-the number of results must be adjusted before they are used (see Section&nbsp;<A HREF="#adjust">4.3</A>).
-If the function is called as a statement (see Section&nbsp;<A HREF="#funcstat">4.4.5</A>),
-then its return list is adjusted to&nbsp;0,
+
+<p>Because a function can return any number of results
+(see <a href="#control">2.4.4</a>),
+the number of results must be adjusted before they are used.
+If the function is called as a statement (see <a href="#funcstat">2.4.6</a>),
+then its return list is adjusted to zero elements,
 thus discarding all returned values.
-If the function is called in a place that needs a single value
-(syntactically denoted by the non-terminal <EM>exp1</EM>),
-then its return list is adjusted to&nbsp;1,
-thus discarding all returned values but the first one.
-If the function is called in a place that can hold many values
-(syntactically denoted by the non-terminal <EM>exp</EM>),
-then no adjustment is made.
-The only places that can hold many values
-is the last (or the only) expression in an assignment,
-in an argument list, or in the <B>return</B> statement.
-Here are some examples:
+If the function is called inside another expression
+or in the middle of a list of expressions,
+then its return list is adjusted to one element,
+thus discarding all returned values except the first one.
+If the function is called as the last element of a list of expressions,
+then no adjustment is made
+(unless the call is enclosed in parentheses).
+
+<p>Here are some examples:
 <PRE>
        f()                -- adjusted to 0 results
        g(f(), x)          -- f() is adjusted to 1 result
        g(x, f())          -- g gets x plus all values returned by f()
        a,b,c = f(), x     -- f() is adjusted to 1 result (and c gets nil)
-       a,b,c = x, f()     -- f() is adjusted to 2
-       a,b,c = f()        -- f() is adjusted to 3
+       a,b,c = x, f()     -- f() is adjusted to 2 results
+       a,b,c = f()        -- f() is adjusted to 3 results
        return f()         -- returns all values returned by f()
-       return x,y,f()     -- returns a, b, and all values returned by f()
+       return x,y,f()     -- returns x, y, and all values returned by f()
+       {f()}              -- creates a list with all values returned by f()
+       {f(), nil}         -- f() is adjusted to 1 result
 </PRE>
-<P>
-<A NAME="func-def"></A>
-<H3>4.5.9 - <A NAME="Function Definitions</H3>">Function Definitions</H3></A> 
-<P>
-The syntax for function definition is
+
+<p>If you enclose a function call in parentheses,
+then it is adjusted to return exactly one value:
 <PRE>
-       function ::= <B>function</B> `<B>(</B>' [parlist1] `<B>)</B>' block <B>end</B>
-       stat ::= <B>function</B> funcname `<B>(</B>' [parlist1] `<B>)</B>' block <B>end</B>
-       funcname ::= name | name `<B>.</B>' name | name `<B>:</B>' name
+       return x,y,(f())   -- returns x, y, and the first value from f()
+       {(f())}            -- creates a table with exactly one element
 </PRE>
+
+<p>As an exception to the free-format syntax of Lua,
+you cannot put a line break before the `<code>(</code>&acute; in a function call.
+That restriction avoids some ambiguities in the language.
+If you write
+<PRE>
+       a = f
+       (g).x(a)
+</PRE>
+Lua would read that as <code>a = f(g).x(a)</code>.
+So, if you want two statements, you must add a semi-colon between them.
+If you actually want to call <code>f</code>,
+you must remove the line break before <code>(g)</code>.
+
+<p>A call of the form <code>return</code> <em>functioncall</em> is called
+a <em>tail call</em>.
+Lua implements <em>proper tail calls</em>
+(or <em>proper tail recursion</em>):
+In a tail call,
+the called function reuses the stack entry of the calling function.
+Therefore, there is no limit on the number of nested tail calls that
+a program can execute.
+However, a tail call erases any debug information about the
+calling function.
+Note that a tail call only happens with a particular syntax,
+where the <b>return</b> has one single function call as argument;
+this syntax makes the calling function returns exactly
+the returns of the called function.
+So, all the following examples are not tails calls:
+<PRE>
+  return (f(x))        -- results adjusted to 1
+  return 2 * f(x)
+  return x, f(x)       -- adicional results
+  f(x); return         -- results discarded
+  return x or f(x)     -- results adjusted to 1
+</PRE>
+
+<p><a name="func-def"><h3>2.5.8 - Function Definitions</h3></a>
+
+<p>The syntax for function definition is
+<pre>
+	function ::= <b>function</b> funcbody
+	funcbody ::= `<b>(</b>&acute; [parlist1] `<b>)</b>&acute; block <b>end</b>
+</pre>
+
+<p>The following syntactic sugar simplifies function definitions:
+<pre>
+	stat ::= <b>function</b> funcname funcbody
+	stat ::= <b>local</b> <b>function</b> Name funcbody
+	funcname ::= Name {`<b>.</b>&acute; Name} [`<b>:</b>&acute; Name]
+</pre>
 The statement
 <PRE>
        function f () ... end
 </PRE>
-is just syntactic sugar for
+translates to
 <PRE>
        f = function () ... end
 </PRE>
-and the statement
+The statement
 <PRE>
-       function v.f () ... end
+       function t.a.b.c.f () ... end
 </PRE>
-is syntactic sugar for
+translates to
+<PRE>
+       t.a.b.c.f = function () ... end
+</PRE>
+The statement
 <PRE>
-       v.f = function () ... end
+       local function f () ... end
 </PRE>
-<P>
-A function definition is an executable expression,
-whose value has type <EM>function</EM>.
+translates to
+<PRE>
+       local f; f = function () ... end
+</PRE>
+
+<p>A function definition is an executable expression,
+whose value has type <em>function</em>.
 When Lua pre-compiles a chunk,
 all its function bodies are pre-compiled too.
 Then, whenever Lua executes the function definition,
-its upvalues are fixed (see Section&nbsp;<A HREF="#upvalue">4.6</A>),
-and the function is <EM>instantiated</EM> (or <EM>closed</EM>).
-This function instance (or <EM>closure</EM>)
+the function is <em>instantiated</em> (or <em>closed</em>).
+This function instance (or <em>closure</em>)
 is the final value of the expression.
 Different instances of the same function
-may have different upvalues.
-<P>
-Parameters act as local variables,
-initialized with the argument values:
-<PRE>
-       parlist1 ::= `<B>...</B>'
-       parlist1 ::= name {`<B>,</B>' name} [`<B>,</B>' `<B>...</B>']
-</PRE>
-<A NAME="vararg"></A>
+may refer to different  external local variables
+and may have different environment tables.
 
+<p>Parameters act as local variables that are
+initialized with the argument values:
+<pre>
+	parlist1 ::= namelist [`<b>,</b>&acute; `<b>...</b>&acute;]
+	parlist1 ::= `<b>...</b>&acute;
+</pre>
 When a function is called,
-the list of <A NAME="arguments">arguments</A> is adjusted to
-the length of the list of parameters (see Section&nbsp;<A HREF="#adjust">4.3</A>),
-unless the function is a <A NAME="vararg function"><EM>vararg function</EM></A>,
+the list of arguments is adjusted to
+the length of the list of parameters,
+unless the function is a variadic or <em>vararg function</em>,
 which is
-indicated by three dots (`<CODE>...</CODE>') at the end of its parameter list.
+indicated by three dots (`<code>...</code>&acute;) at the end of its parameter list.
 A vararg function does not adjust its argument list;
 instead, it collects all extra arguments into an implicit parameter,
-called <A NAME="arg"><TT>arg</TT></A>.
-The value of <CODE>arg</CODE> is a table,
-with a field&nbsp;<CODE>n</CODE> whose value is the number of extra arguments,
-and the extra arguments at positions 1,&nbsp;2,&nbsp;...,&nbsp;<CODE>n</CODE>.
-<P>
-As an example, consider the following definitions:
+called <code>arg</code>.
+The value of <a name="vararg"><code>arg</code></a> is a table,
+with a field&nbsp;<code>n</code> that holds the number of extra arguments
+and with the extra arguments at positions 1,&nbsp;2,&nbsp;...,&nbsp;<code>n</code>.
+
+<p>As an example, consider the following definitions:
 <PRE>
        function f(a, b) end
        function g(a, b, ...) end
@@ -951,1200 +1028,1428 @@ As an example, consider the following definitions:
 Then, we have the following mapping from arguments to parameters:
 <PRE>
        CALL            PARAMETERS
-<P>
+
        f(3)             a=3, b=nil
        f(3, 4)          a=3, b=4
        f(3, 4, 5)       a=3, b=4
        f(r(), 10)       a=1, b=10
        f(r())           a=1, b=2
-<P>
+
        g(3)             a=3, b=nil, arg={n=0}
-       g(3, 4)          a=3, b=4, arg={n=0}
-       g(3, 4, 5, 8)    a=3, b=4, arg={5, 8; n=2}
-       g(5, r())        a=5, b=1, arg={2, 3; n=2}
+       g(3, 4)          a=3, b=4,   arg={n=0}
+       g(3, 4, 5, 8)    a=3, b=4,   arg={5, 8; n=2}
+       g(5, r())        a=5, b=1,   arg={2, 3; n=2}
 </PRE>
-<P>
-Results are returned using the <B>return</B> statement (see Section&nbsp;<A HREF="#return">4.4.3</A>).
+
+<p>Results are returned using the <b>return</b> statement (see <a href="#control">2.4.4</a>).
 If control reaches the end of a function
-without encountering a <B>return</B> statement,
+without encountering a <b>return</b> statement,
 then the function returns with no results.
-<P>
-The syntax
+
+<p>The <em>colon</em> syntax
+is used for defining <em>methods</em>,
+that is, functions that have an implicit extra parameter <code>self</code>.
+Thus, the statement
 <PRE>
-       funcname ::= name `<B>:</B>' name
+       function t.a.b.c:f (...) ... end
 </PRE>
-is used for defining <A NAME="methods"><EM>methods</EM></A>,
-that is, functions that have an implicit extra parameter <A NAME="self"><TT>self</TT></A>.
-<P>
-The statement
+is syntactic sugar for
 <PRE>
-       function v:f (...) ... end
-</PRE>
-is just syntactic sugar for
-<PRE>
-       v.f = function (self, ...) ... end
-</PRE>
-Note that the function gets an extra formal parameter called <CODE>self</CODE>.
-<P>
-<P>
-<A NAME="upvalue"></A>
-<A NAME="4.6"></A>
-<H2>4.6 - Visibility and Upvalues</H2> 
-<A NAME="visibility"></A><A NAME="upvalues"></A>
-<P>
-A function body may refer to its own local variables
-(which include its parameters) and to global variables,
-as long as they are not <EM>shadowed</EM> by local
-variables with the same name from enclosing functions.
-A function <EM>cannot</EM> access a local
-variable from an enclosing function,
-since such variables may no longer exist when the function is called.
-However, a function may access the <EM>value</EM> of a local variable
-from an enclosing function, using <EM>upvalues</EM>,
-whose syntax is
-<PRE>
-       upvalue ::= `<B>%</B>' name
-</PRE>
-<P>
-An upvalue is somewhat similar to a variable expression,
-but whose value is <EM>frozen</EM> when the function wherein it
-appears is instantiated.
-The name used in an upvalue may be the name of any variable visible
-at the point where the function is defined,
-that is,
-global variables and local variables
-from the <EM>immediately enclosing</EM> function.
-Note that when the upvalue is a table,
-only the <EM>reference</EM> to that table
-(which is the value of the upvalue) is frozen;
-the table contents can be changed at will.
-Using table values as upvalues is a technique for having
-writable but private state attached to functions.
-<P>
-Here are some examples:
-<PRE>
-       a,b,c = 1,2,3   -- global variables
-       local d
-       function f (x)
-         local b = {}  -- x and b are local to f; b shadows the global b
-         local g = function (a)
-           local y     -- a and y are local to g
-           p = a       -- OK, access local `a'
-           p = c       -- OK, access global `c'
-           p = b       -- ERROR: cannot access a variable in outer scope
-           p = %b      -- OK, access frozen value of `b' (local to `f')
-           %b = 3      -- ERROR: cannot change an upvalue
-           %b.x = 3    -- OK, change the table contents
-           p = %c      -- OK, access frozen value of global `c'
-           p = %y      -- ERROR: `y' is not visible where `g' is defined
-           p = %d      -- ERROR: `d' is not visible where `g' is defined
-         end           -- g
-       end             -- f
-</PRE>
-<P>
-<P>
-<A NAME="error"></A>
-<A NAME="4.7"></A>
-<H2>4.7 - Error Handling</H2> 
-<P>
-Because Lua is an extension language,
+       t.a.b.c.f = function (self, ...) ... end
+</PRE>
+
+<p><a name="visibility"><h2>2.6 - Visibility Rules</h2></a>
+
+
+<p>Lua is a lexically scoped language.
+The scope of variables begins at the first statement <em>after</em>
+their declaration and lasts until the end of the innermost block that
+includes the declaration.
+For instance:
+<PRE>
+  x = 10                -- global variable
+  do                    -- new block
+    local x = x         -- new `x', with value 10
+    print(x)            --> 10
+    x = x+1
+    do                  -- another block
+      local x = x+1     -- another `x'
+      print(x)          --> 12
+    end
+    print(x)            --> 11
+  end
+  print(x)              --> 10  (the global one)
+</PRE>
+Notice that, in a declaration like <code>local x = x</code>,
+the new <code>x</code> being declared is not in scope yet,
+and so the second <code>x</code> refers to the outside variable.
+
+<p>Because of the lexical scoping rules,
+local variables can be freely accessed by functions
+defined inside their scope.
+For instance:
+<PRE>
+  local counter = 0
+  function inc (x)
+    counter = counter + x
+    return counter
+  end
+</PRE>
+A local variable used by an inner function is called
+an <em>upvalue</em>, or <em>external local variable</em>,
+inside the inner function.
+
+<p>Notice that each execution of a <b>local</b> statement
+defines new local variables.
+Consider the following example:
+<PRE>
+  a = {}
+  local x = 20
+  for i=1,10 do
+    local y = 0
+    a[i] = function () y=y+1; return x+y end
+  end
+</PRE>
+The loop creates ten closures
+(that is, ten instances of the anonymous function).
+Each of these closures uses a different <code>y</code> variable,
+while all of them share the same <code>x</code>.
+
+<p><a name="error"><h2>2.7 - Error Handling</h2></a>
+
+<p>Because Lua is an extension language,
 all Lua actions start from C&nbsp;code in the host program
-calling a function from the Lua library.
+calling a function from the Lua library (see <a href="#lua_pcall">3.15</a>).
 Whenever an error occurs during Lua compilation or execution,
-the function <CODE>_ERRORMESSAGE</CODE> is called <A NAME="_ERRORMESSAGE"></A>
-(provided it is different from <B>nil</B>),
-and then the corresponding function from the library
-(<CODE>lua_dofile</CODE>, <CODE>lua_dostring</CODE>,
-<CODE>lua_dobuffer</CODE>, or <CODE>lua_call</CODE>)
-is terminated, returning an error condition.
-<P>
-Memory allocation errors are an exception to the previous rule.
-When memory allocation fails, Lua may not be able to execute the
-<CODE>_ERRORMESSAGE</CODE> function.
-So, for this kind of error, Lua does not call
-the <CODE>_ERRORMESSAGE</CODE> function;
-instead, the corresponding function from the library
-returns immediately with a special error code (<CODE>LUA_ERRMEM</CODE>).
-This and other error codes are defined in <CODE>lua.h</CODE>;
-Section&nbsp;<A HREF="#luado">5.8</A>.
-<P>
-The only argument to <CODE>_ERRORMESSAGE</CODE> is a string
-describing the error.
-The default definition for
-this function calls <CODE>_ALERT</CODE>, <A NAME="_ALERT"></A>
-which prints the message to <CODE>stderr</CODE> (see Section&nbsp;<A HREF="#alert">6.1</A>).
-The standard I/O library redefines <CODE>_ERRORMESSAGE</CODE>
-and uses the debug facilities (see Section&nbsp;<A HREF="#debugI">7</A>)
-to print some extra information,
-such as a call stack traceback.
-<P>
-Lua code can explicitly generate an error by calling the
-function <CODE>error</CODE> (see Section&nbsp;<A HREF="#pdf-error">6.1</A>).
-Lua code can ``catch'' an error using the function
-<CODE>call</CODE> (see Section&nbsp;<A HREF="#pdf-call">6.1</A>).
-<P>
-<P>
-<A NAME="tag-method"></A>
-<A NAME="4.8"></A>
-<H2>4.8 - Tag Methods</H2> 
-<P>
-Lua provides a powerful mechanism to extend its semantics,
-called <EM>tag methods</EM>.
-A tag method is a programmer-defined function
-that is called at specific key points during the execution of a Lua program,
-allowing the programmer to change the standard Lua behavior at these points.
-Each of these points is called an <A NAME="event"><EM>event</EM></A>.
-<P>
-The tag method called for any specific event is selected
-according to the tag of the values involved
-in the event (see Section&nbsp;<A HREF="#TypesSec">3</A>).
-The function <A NAME="settagmethod"><TT>settagmethod</TT></A> changes the tag method
-associated with a given pair <EM>(tag, event)</EM>.
-Its first parameter is the tag, the second parameter is the event name
-(a string; see below),
-and the third parameter is the new method (a function),
-or <B>nil</B> to restore the default behavior for the pair.
-The <CODE>settagmethod</CODE> function returns the previous tag method for that pair.
-A companion function <A NAME="gettagmethod"><TT>gettagmethod</TT></A>
-receives a tag and an event name and returns the
-current method associated with the pair.
-<P>
-Tag methods are called in the following events,
-identified by the given names.
-The semantics of tag methods is better explained by a Lua function
-describing the behavior of the interpreter at each event.
-This function not only shows when a tag method is called,
-but also its arguments, its results, and the default behavior.
-The code shown here is only <EM>illustrative</EM>;
-the real behavior is hard coded in the interpreter,
+control returns to C,
+which can take appropriate measures
+(such as print an error message).
+
+<p>Lua code can explicitly generate an error by calling the
+<code>error</code> function (see <a href="#pdf-error">5.1</a>).
+If you need to catch errors in Lua,
+you can use the <code>pcall</code> function (see <a href="#pdf-pcall">5.1</a>).
+
+<p><a name="metatable"><h2>2.8 - Metatables</h2></a>
+
+<p>Every table and userdata object in Lua may have a <em>metatable</em>.
+This <em>metatable</em> is an ordinary Lua table
+that defines the behavior of the original table and userdata
+under certain special operations.
+You can change several aspects of the behavior
+of an object by setting specific fields in its metatable.
+For instance, when an object is the operand of an addition,
+Lua checks for a function in the field <code>"__add"</code> in its metatable.
+If it finds one,
+Lua calls that function to perform the addition.
+
+<p>We call the keys in a metatable <em>events</em>
+and the values <em>metamethods</em>.
+In the previous example, the event is <code>"add"</code> 
+and the metamethod is the function that performs the addition.
+
+<p>You can query and change the metatable of an object
+through the <code>set/getmetatable</code>
+functions (see <a href="#pdf-getmetatable">5.1</a>).
+
+<p>A metatable may control how an object behaves in arithmetic operations,
+order comparisons, concatenation, and indexing.
+A metatable can also define a function to be called when a userdata
+is garbage collected.
+For each of those operations Lua associates a specific key
+called an <em>event</em>.
+When Lua performs one of those operations over a table or a userdata,
+it checks whether that object has a metatable with the corresponding event.
+If so, the value associated with that key (the <em>metamethod</em>)
+controls how Lua will perform the operation.
+
+<p>Metatables control the operations listed next.
+Each operation is identified by its corresponding name.
+The key for each operation is a string with its name prefixed by
+two underscores;
+for instance, the key for operation "add" is the
+string <code>"__add"</code>.
+The semantics of these operations is better explained by a Lua function
+describing how the interpreter executes that operation.
+
+<p>The code shown here in Lua is only illustrative;
+the real behavior is hard coded in the interpreter
 and it is much more efficient than this simulation.
 All functions used in these descriptions
-(<CODE>rawget</CODE>, <CODE>tonumber</CODE>, <CODE>call</CODE>, etc.)
-are described in Section&nbsp;<A HREF="#predefined">6.1</A>.
-<P>
-<DL>
-<P>
-<DT><B>``add'':</B><DD><A NAME="add event"></A>
-called when a <CODE>+</CODE> operation is applied to non-numerical operands.
-<P>
-The function <CODE>getbinmethod</CODE> below defines how Lua chooses a tag method
+(<code>rawget</code>, <code>tonumber</code>, etc.)
+are described in <a href="#predefined">5.1</a>.
+In particular, to retrieve the metamethod of a given object,
+we use the expression
+<PRE>
+  metatable(obj)[event]
+</PRE>
+This should be read as
+<PRE>
+  rawget(metatable(obj) or {}, event)
+</PRE>
+That is, the access to a metamethod does not invoke other metamethods,
+and the access to objects with no metatables does not fail
+(it simply results in <B>nil</B>).
+
+<p><ul>
+
+<p><li><b>"add":</b>
+the <code>+</code> operation.
+
+<p>The function <code>getbinhandler</code> below defines how Lua chooses a handler
 for a binary operation.
 First, Lua tries the first operand.
-If its tag does not define a tag method for the operation,
+If its type does not define a handler for the operation,
 then Lua tries the second operand.
-If it also fails, then it gets a tag method from tag&nbsp;0.
 <PRE>
-       function getbinmethod (op1, op2, event)
-         return gettagmethod(tag(op1), event) or
-                gettagmethod(tag(op2), event) or
-                gettagmethod(0, event)
-       end
-</PRE>
-Using this function,
-the tag method for the ``add'' event is
-<PRE>
-       function add_event (op1, op2)
-         local o1, o2 = tonumber(op1), tonumber(op2)
-         if o1 and o2 then  -- both operands are numeric
-           return o1+o2  -- '+' here is the primitive 'add'
-         else  -- at least one of the operands is not numeric
-           local tm = getbinmethod(op1, op2, "add")
-           if tm then
-             -- call the method with both operands and an extra
-             -- argument with the event name
-             return tm(op1, op2, "add")
-           else  -- no tag method available: default behavior
-             error("unexpected type at arithmetic operation")
-           end
-         end
-       end
-</PRE>
-<P>
-<DT><B>``sub'':</B><DD><A NAME="sub event"></A>
-called when a <CODE>-</CODE> operation is applied to non-numerical operands.
-Behavior similar to the ``add'' event.
-<P>
-<DT><B>``mul'':</B><DD><A NAME="mul event"></A>
-called when a <CODE>*</CODE> operation is applied to non-numerical operands.
-Behavior similar to the ``add'' event.
-<P>
-<DT><B>``div'':</B><DD><A NAME="div event"></A>
-called when a <CODE>/</CODE> operation is applied to non-numerical operands.
-Behavior similar to the ``add'' event.
-<P>
-<DT><B>``pow'':</B><DD><A NAME="pow event"></A>
-called when a <CODE>^</CODE> operation (exponentiation) is applied,
-even for numerical operands.
-<PRE>
-       function pow_event (op1, op2)
-         local tm = getbinmethod(op1, op2, "pow")
-         if tm then
-           -- call the method with both operands and an extra
-           -- argument with the event name
-           return tm(op1, op2, "pow")
-         else  -- no tag method available: default behavior
-           error("unexpected type at arithmetic operation")
-         end
-       end
-</PRE>
-<P>
-<DT><B>``unm'':</B><DD><A NAME="unm event"></A>
-called when a unary <CODE>-</CODE> operation is applied to a non-numerical operand.
-<PRE>
-       function unm_event (op)
-         local o = tonumber(op)
-         if o then  -- operand is numeric
-           return -o  -- '-' here is the primitive 'unm'
-         else  -- the operand is not numeric.
-           -- Try to get a tag method from the operand;
-           --  if it does not have one, try a "global" one (tag 0)
-           local tm = gettagmethod(tag(op), "unm") or
-                      gettagmethod(0, "unm")
-           if tm then
-             -- call the method with the operand, nil, and an extra
-             -- argument with the event name
-             return tm(op, nil, "unm")
-           else  -- no tag method available: default behavior
-             error("unexpected type at arithmetic operation")
-           end
-         end
-       end
+ function getbinhandler (op1, op2, event)
+   return metatable(op1)[event] or metatable(op2)[event]
+ end
+</PRE>
+Using that function,
+the behavior of the <code>op1 + op2</code> is
+<PRE>
+ function add_event (op1, op2)
+   local o1, o2 = tonumber(op1), tonumber(op2)
+   if o1 and o2 then  -- both operands are numeric?
+     return o1 + o2   -- `+' here is the primitive `add'
+   else  -- at least one of the operands is not numeric
+     local h = getbinhandler(op1, op2, "__add")
+     if h then
+       -- call the handler with both operands
+       return h(op1, op2)
+     else  -- no handler available: default behavior
+       error("...")
+     end
+   end
+ end
 </PRE>
-<P>
-<DT><B>``lt'':</B><DD><A NAME="lt event"></A>
-called when an order operation is applied to non-numerical
-or non-string operands.
-It corresponds to the <CODE>&lt;</CODE> operator.
-<PRE>
-       function lt_event (op1, op2)
-         if type(op1) == "number" and type(op2) == "number" then
-           return op1 &lt; op2   -- numeric comparison
-         elseif type(op1) == "string" and type(op2) == "string" then
-           return op1 &lt; op2   -- lexicographic comparison
-         else
-           local tm = getbinmethod(op1, op2, "lt")
-           if tm then
-             return tm(op1, op2, "lt")
-           else
-             error("unexpected type at comparison");
-           end
-         end
-       end
+
+<p><li><b>"sub":</b>
+the <code>-</code> operation.
+Behavior similar to the "add" operation.
+
+<p><li><b>"mul":</b>
+the <code>*</code> operation.
+Behavior similar to the "add" operation.
+
+<p><li><b>"div":</b>
+the <code>/</code> operation.
+Behavior similar to the "add" operation.
+
+<p><li><b>"pow":</b>
+the <code>^</code> (exponentiation) operation.
+<PRE>
+ function pow_event (op1, op2)
+   local o1, o2 = tonumber(op1), tonumber(op2)
+   if o1 and o2 then  -- both operands are numeric?
+     return __pow(o1, o2)   -- call global `__pow'
+   else  -- at least one of the operands is not numeric
+     local h = getbinhandler(op1, op2, "__pow")
+     if h then
+       -- call the handler with both operands
+       return h(op1, op2)
+     else  -- no handler available: default behavior
+       error("...")
+     end
+   end
+  end
 </PRE>
-The other order operators use this tag method according to the
-usual equivalences:
-<PRE>
-       a&gt;b    &lt;=&gt;  b&lt;a
-       a&lt;=b   &lt;=&gt;  not (b&lt;a)
-       a&gt;=b   &lt;=&gt;  not (a&lt;b)
-</PRE>
-<P>
-<DT><B>``concat'':</B><DD><A NAME="concatenation event"></A>
-called when a concatenation is applied to non-string operands.
-<PRE>
-       function concat_event (op1, op2)
-         if (type(op1) == "string" or type(op1) == "number") and
-            (type(op2) == "string" or type(op2) == "number") then
-           return op1..op2  -- primitive string concatenation
-         else
-           local tm = getbinmethod(op1, op2, "concat")
-           if tm then
-             return tm(op1, op2, "concat")
-           else
-             error("unexpected type for concatenation")
-           end
-         end
-       end
+
+<p><li><b>"unm":</b>
+the unary <code>-</code> operation.
+<PRE>
+ function unm_event (op)
+   local o = tonumber(op)
+   if o then  -- operand is numeric?
+     return -o  -- `-' here is the primitive `unm'
+   else  -- the operand is not numeric.
+     -- Try to get a handler from the operand
+     local h = metatable(op).__unm
+     if h then
+       -- call the handler with the operand and nil
+       return h(op, nil)
+     else  -- no handler available: default behavior
+       error("...")
+     end
+   end
+ end
 </PRE>
-<P>
-<DT><B>``index'':</B><DD><A NAME="index event"></A>
-called when Lua tries to retrieve the value of an index
-not present in a table.
-See the ``gettable'' event for its semantics.
-<P>
-<DT><B>``getglobal'':</B><DD><A NAME="getglobal event"></A>
-called whenever Lua needs the value of a global variable.
-This method can only be set for <B>nil</B> and for tags
-created by <CODE>newtag</CODE>.
-Note that
-the tag is that of the <EM>current value</EM> of the global variable.
-<PRE>
-       function getglobal (varname)
-         -- access the table of globals
-         local value = rawget(globals(), varname)
-         local tm = gettagmethod(tag(value), "getglobal")
-         if not tm then
-           return value
-         else
-           return tm(varname, value)
-         end
-       end
+
+<p><li><b>"concat":</b>
+the <code>..</code> (concatenation) operation.
+<PRE>
+ function concat_event (op1, op2)
+   if (type(op1) == "string" or type(op1) == "number") and
+      (type(op2) == "string" or type(op2) == "number") then
+     return op1 .. op2  -- primitive string concatenation
+   else
+     local h = getbinhandler(op1, op2, "__concat")
+     if h then
+       return h(op1, op2)
+     else
+       error("...")
+     end
+   end
+ end
 </PRE>
-The function <CODE>getglobal</CODE> is defined in the basic library&nbsp;(see Section&nbsp;<A HREF="#predefined">6.1</A>).
-<P>
-<DT><B>``setglobal'':</B><DD><A NAME="setglobal event"></A>
-called whenever Lua assigns to a global variable.
-This method cannot be set for numbers, strings, and tables and
-userdata with the default tag.
-<PRE>
-       function setglobal (varname, newvalue)
-         local oldvalue = rawget(globals(), varname)
-         local tm = gettagmethod(tag(oldvalue), "setglobal")
-         if not tm then
-           rawset(globals(), varname, newvalue)
-         else
-           tm(varname, oldvalue, newvalue)
-         end
+
+<p><li><b>"eq":</b>
+the <code>==</code> operation.
+The function <code>getcomphandler</code> defines how Lua chooses a metamethod
+for comparison operators.
+A metamethod only is selected when both objects
+being compared have the same type
+and the same metamethod for the selected operation.
+<PRE>
+ function getcomphandler (op1, op2, event)
+   if type(op1) ~= type(op2) then return nil end
+   local mm1 = metatable(op1)[event]
+   local mm2 = metatable(op2)[event]
+   if mm1 == mm2 then return mm1 else return nil end
+ end
+</PRE>
+The "eq" event is defined as follows:
+<PRE>
+ function eq_event (op1, op2)
+   if type(op1) ~= type(op2) then  -- diferent types?
+     return false   -- different objects
+   end
+   if op1 == op2 then   -- primitive equal?
+     return true   -- objects are equal
+   end
+   -- try metamethod
+   local h = getcomphandler(op1, op2, "__eq")
+   if h then
+     return h(op1, op2)
+   else
+     return false
+   end
+ end
+</PRE>
+<code>a ~= b</code> is equivalent to <code>not (a == b)</code>.
+
+<p><li><b>"lt":</b>
+the <code>&#060;</code> operation.
+<PRE>
+ function lt_event (op1, op2)
+   if type(op1) == "number" and type(op2) == "number" then
+     return op1 &#060; op2   -- numeric comparison
+   elseif type(op1) == "string" and type(op2) == "string" then
+     return op1 &#060; op2   -- lexicographic comparison
+   else
+     local h = getcomphandler(op1, op2, "__lt")
+     if h then
+       return h(op1, op2)
+     else
+       error("...");
+     end
+   end
+ end
+</PRE>
+<code>a > b</code> is equivalent to <code>b &#060; a</code>.
+
+<p><li><b>"le":</b>
+the <code>&#060;=</code> operation.
+<PRE>
+ function le_event (op1, op2)
+   if type(op1) == "number" and type(op2) == "number" then
+     return op1 &#060;= op2   -- numeric comparison
+   elseif type(op1) == "string" and type(op2) == "string" then
+     return op1 &#060;= op2   -- lexicographic comparison
+   else
+     local h = getcomphandler(op1, op2, "__le")
+     if h then
+       return h(op1, op2)
+     else
+       h = getcomphandler(op1, op2, "__lt")
+       if h then
+         return not h(op2, op1)
+       else
+         error("...");
        end
+     end
+   end
+ end
+</PRE>
+<code>a >= b</code> is equivalent to <code>b &#060;= a</code>.
+Note that, in the absence of a "le" metamethod,
+Lua tries the "lt", assuming that <code>a &#060;= b</code> is
+equivalent to <code>not (b &#060; a)</code>.
+
+<p><li><b>"index":</b>
+The indexing access <code>table[key]</code>.
+<PRE>
+ function gettable_event (table, key)
+   local h
+   if type(table) == "table" then
+     local v = rawget(table, key)
+     if v ~= nil then return v end
+     h = metatable(table).__index
+     if h == nil then return nil end
+   else
+     h = metatable(table).__index
+     if h == nil then
+       error("...");
+     end
+   end
+   if type(h) == "function" then
+     return h(table, key)      -- call the handler
+   else return h[key]          -- or repeat operation on it
+ end
 </PRE>
-The function <CODE>setglobal</CODE> is defined in the basic library&nbsp;(see Section&nbsp;<A HREF="#predefined">6.1</A>).
-<P>
-<DT><B>``gettable'':</B><DD><A NAME="gettable event"></A>
-called whenever Lua accesses an indexed variable.
-This method cannot be set for tables with the default tag.
-<PRE>
-       function gettable_event (table, index)
-         local tm = gettagmethod(tag(table), "gettable")
-         if tm then
-           return tm(table, index)
-         elseif type(table) ~= "table" then
-           error("indexed expression not a table");
-         else
-           local v = rawget(table, index)
-           tm = gettagmethod(tag(table), "index")
-           if v == nil and tm then
-             return tm(table, index)
-           else
-             return v
-           end
-         end
-       end
+
+<p><li><b>"newindex":</b>
+The indexing assignment <code>table[key] = value</code>.
+<PRE>
+ function settable_event (table, key, value)
+   local h
+   if type(table) == "table" then
+     local v = rawget(table, key)
+     if v ~= nil then rawset(table, key, value); return end
+     h = metatable(table).__newindex
+     if h == nil then rawset(table, key, value); return end
+   else
+     h = metatable(table).__newindex
+     if h == nil then
+       error("...");
+     end
+   end
+   if type(h) == "function" then
+     return h(table, key,value)    -- call the handler
+   else h[key] = value             -- or repeat operation on it
+ end
 </PRE>
-<P>
-<DT><B>``settable'':</B><DD><A NAME="settable event"></A>
-called when Lua assigns to an indexed variable.
-This method cannot be set for tables with the default tag.
-<PRE>
-       function settable_event (table, index, value)
-         local tm = gettagmethod(tag(table), "settable")
-         if tm then
-           tm(table, index, value)
-         elseif type(table) ~= "table" then
-           error("indexed expression not a table")
-         else
-           rawset(table, index, value)
-         end
-       end
+
+<p><li><b>"call":</b>
+called when Lua calls a value.
+<PRE>
+ function function_event (func, ...)
+   if type(func) == "function" then
+     return func(unpack(arg))   -- primitive call
+   else
+     local h = metatable(func).__call
+     if h then
+       return h(func, unpack(arg))
+     else
+       error("...")
+     end
+   end
+ end
 </PRE>
-<P>
-<DT><B>``function'':</B><DD><A NAME="function event"></A>
-called when Lua tries to call a non-function value.
-<PRE>
-       function function_event (func, ...)
-         if type(func) == "function" then
-           return call(func, arg)
-         else
-           local tm = gettagmethod(tag(func), "function")
-           if tm then
-             for i=arg.n,1,-1 do
-               arg[i+1] = arg[i]
-             end
-             arg.n = arg.n+1
-             arg[1] = func
-             return call(tm, arg)
-           else
-             error("call expression not a function")
-           end
-         end
-       end
+
+<p></ul>
+
+<p><a name="GC"><h2>2.9 - Garbage Collection</h2></a>
+
+<p>Lua does automatic memory management.
+That means that
+you do not have to worry about allocating memory for new objects
+and freeing it when the objects are no longer needed.
+Lua manages memory automatically by running
+a <em>garbage collector</em> from time to time
+to collect all <em>dead objects</em>
+(that is, those objects that are no longer accessible from Lua).
+All objects in Lua are subject to automatic management:
+tables, userdata, functions, threads, and strings.
+
+<p>Lua uses two numbers to control its garbage-collection cycles.
+One number counts how many bytes of dynamic memory Lua is using;
+the other is a threshold.
+When the number of bytes crosses the threshold,
+Lua runs the garbage collector,
+which reclaims the memory of all dead objects.
+The byte counter is adjusted,
+and then the threshold is reset to twice the new value of the byte counter.
+
+<p>Through the C&nbsp;API, you can query those numbers
+and change the threshold (see <a href="#GC-API">3.7</a>).
+Setting the threshold to zero actually forces an immediate
+garbage-collection cycle,
+while setting it to a huge number effectively stops the garbage collector.
+Using Lua code you have a more limited control over garbage-collection cycles,
+through the <code>gcinfo</code> and <code>collectgarbage</code> functions
+(see <a href="#predefined">5.1</a>).
+
+<p><h3>2.9.1 - Garbage-Collection Metamethods</h3>
+
+<p>Using the C&nbsp;API,
+you can set garbage-collector metamethods for userdata (see <a href="#metatable">2.8</a>).
+These metamethods are also called <em>finalizers</em>.
+Finalizers allow you to coordinate Lua's garbage collection
+with external resource management
+(such as closing files, network or database connections,
+or freeing your own memory).
+
+<p>Free userdata with a field <code>__gc</code> in their metatables are not
+collected immediately by the garbage collector.
+Instead, Lua puts them in a list.
+After the collection,
+Lua does the equivalent of the following function
+for each userdata in that list:
+<PRE>
+ function gc_event (udata)
+   local h = metatable(udata).__gc
+   if h then
+     h(udata)
+   end
+ end
 </PRE>
-<P>
-<DT><B>``gc'':</B><DD><A NAME="gc event"></A>
-called when Lua is ``garbage collecting'' a userdata.
-This tag method can be set only from&nbsp;C,
-and cannot be set for a userdata with the default tag.
-For each userdata to be collected,
-Lua does the equivalent of the following function:
-<PRE>
-       function gc_event (obj)
-         local tm = gettagmethod(tag(obj), "gc")
-         if tm then
-           tm(obj)
-         end
-       end
+
+<p>At the end of each garbage-collection cycle,
+the finalizers for userdata are called in <em>reverse</em>
+order of their creation,
+among those collected in that cycle.
+That is, the first finalizer to be called is the one associated
+with the userdata created last in the program.
+
+<p><a name="weak-table"><h3>2.9.2 - Weak Tables</h3></a>
+
+<p>A <em>weak table</em> is a table whose elements are
+<em>weak references</em>.
+A weak reference is ignored by the garbage collector.
+In other words,
+if the only references to an object are weak references,
+then the garbage collector will collect that object.
+
+<p>A weak table can have weak keys, weak values, or both.
+A table with weak keys allows the collection of its keys,
+but prevents the collection of its values.
+A table with both weak keys and weak values allows the collection of
+both keys and values.
+In any case, if either the key or the value is collected,
+the whole pair is removed from the table.
+The weakness of a table is controlled by the value of the
+<code>__mode</code> field of its metatable.
+If the <code>__mode</code> field is a string containing the character `<code>k</code>&acute;,
+the keys in the table are weak.
+If <code>__mode</code> contains `<code>v</code>&acute;,
+the values in the table are weak.
+
+<p>After you use a table as a metatable,
+you should not change the value of its field <code>__mode</code>.
+Otherwise, the weak behavior of the tables controlled by this
+metatable is undefined.
+
+<p><a name="coroutine"><h2>2.10 - Coroutines</h2></a>
+
+<p>Lua supports coroutines,
+also called <em>semi-coroutines</em>
+or <em>collaborative multithreading</em>.
+A coroutine in Lua represents an independent thread of execution.
+Unlike threads in multithread systems, however,
+a coroutine only suspends its execution by explicitly calling
+a yield function.
+
+<p>You create a coroutine with a call to <code>coroutine.create</code>.
+Its sole argument is a function
+that is the main function of the coroutine.
+The <code>create</code> function only creates a new coroutine and
+returns a handle to it (an object of type <em>thread</em>);
+it does not start the coroutine execution.
+
+<p>When you first call <code>coroutine.resume</code>,
+passing as argument the thread returned by <code>coroutine.create</code>,
+the coroutine starts its execution,
+at the first line of its main function.
+Extra arguments passed to <code>coroutine.resume</code> are given as
+parameters for the coroutine main function.
+After the coroutine starts running,
+it runs until it terminates or <em>yields</em>.
+
+<p>A coroutine can terminate its execution in two ways:
+Normally, when its main function returns
+(explicitly or implicitly, after the last instruction);
+and abnormally, if there is an unprotected error.
+In the first case, <code>coroutine.resume</code> returns <B>true</B>,
+plus any values returned by the coroutine main function.
+In case of errors, <code>coroutine.resume</code> returns <B>false</B>
+plus an error message.
+
+<p>A coroutine yields by calling <code>coroutine.yield</code>.
+When a coroutine yields,
+the corresponding <code>coroutine.resume</code> returns immediately,
+even if the yield happens inside nested function calls
+(that is, not in the main function,
+but in a function directly or indirectly called by the main function).
+In the case of a yield, <code>coroutine.resume</code> also returns <B>true</B>,
+plus any values passed to <code>coroutine.yield</code>.
+The next time you resume the same coroutine,
+it continues its execution from the point where it yielded,
+with the call to <code>coroutine.yield</code> returning any extra
+arguments passed to <code>coroutine.resume</code>.
+
+<p>The <code>coroutine.wrap</code> function creates a coroutine
+like <code>coroutine.create</code>,
+but instead of returning the coroutine itself,
+it returns a function that, when called, resumes the coroutine.
+Any arguments passed to that function
+go as extra arguments to resume.
+The function returns all the values returned by resume,
+except the first one (the boolean error code).
+Unlike <code>coroutine.resume</code>,
+this function does not catch errors;
+any error is propagated to the caller.
+
+<p>As an example,
+consider the next code:
+<PRE>
+function foo1 (a)
+  print("foo", a)
+  return coroutine.yield(2*a)
+end
+
+co = coroutine.create(function (a,b)
+      print("co-body", a, b)
+      local r = foo1(a+1)
+      print("co-body", r)
+      local r, s = coroutine.yield(a+b, a-b)
+      print("co-body", r, s)
+      return b, "end"
+end)
+       
+a, b = coroutine.resume(co, 1, 10)
+print("main", a, b)
+a, b, c = coroutine.resume(co, "r")
+print("main", a, b, c)
+a, b, c = coroutine.resume(co, "x", "y")
+print("main", a, b, c)
+a, b = coroutine.resume(co, "x", "y")
+print("main", a, b)
+</PRE>
+When you run it, it produces the following output:
+<PRE>
+co-body 1       10
+foo     2
+main    true    4
+co-body r
+main    true    11      -9
+co-body x       y
+main    true    10      end
+main    false   cannot resume dead coroutine
 </PRE>
-In a garbage-collection cycle,
-the tag methods for userdata are called in <EM>reverse</EM> order of tag creation,
-that is, the first tag methods to be called are those associated
-with the last tag created in the program.
-Moreover, at the end of the cycle,
-Lua does the equivalent of the call <CODE>gc_event(nil)</CODE>.
-<P>
-</DL>
-<P>
-<P>
-<P>
-<P>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="5."></A>
-<H1>5 - The Application Program Interface</H1>
-<A NAME="C API"></A>
-This section describes the API for Lua, that is,
+
+<p>
+<a name="API"><h1>3 - The Application Program Interface</h1></a>
+
+
+<p>This section describes the C API for Lua, that is,
 the set of C&nbsp;functions available to the host program to communicate
 with Lua.
 All API functions and related types and constants
-are declared in the header file <CODE>lua.h</CODE>.
-<P>
-Even when we use the term ``function'',
-any facility in the API may be provided as a <EM>macro</EM> instead.
-All such macros use each of its arguments exactly once,
+are declared in the header file <code>lua.h</code>.
+
+<p>Even when we use the term "function",
+any facility in the API may be provided as a <em>macro</em> instead.
+All such macros use each of its arguments exactly once
+(except for the first argument, which is always a Lua state),
 and so do not generate hidden side-effects.
-<P>
-<P>
-<A NAME="mangstate"></A>
-<A NAME="5.1"></A>
-<H2>5.1 - States</H2> 
-<P>
-The Lua library is fully reentrant:
-it does not have any global variables.
-<A NAME="state"></A>
+
+<p><a name="mangstate"><h2>3.1 - States</h2></a>
+
+<p>The Lua library is fully reentrant:
+it has no global variables.
+
 The whole state of the Lua interpreter
-(global variables, stack, tag methods, etc.)
-is stored in a dynamically allocated structure of type <CODE>lua_State</CODE>; <A NAME="lua_State"></A>
-this state must be passed as the first argument to
-every function in the library (except <CODE>lua_open</CODE> below).
-<P>
-Before calling any API function,
-you must create a state by calling
-<A NAME="lua_open"></A>
-<PRE>
-       lua_State *lua_open (int stacksize);
-</PRE>
-The sole argument to this function is the stack size for the interpreter.
-(Each function call needs one stack position for each argument, local variable,
-and temporary value, plus one position for book-keeping.
-The stack must also have some 20 extra positions available.
-For very small implementations, without recursive functions,
-a stack size of&nbsp;100 should be enough.)
-If <CODE>stacksize</CODE> is zero,
-then a default size of&nbsp;1024 is used.
-<P>
-To release a state created with <CODE>lua_open</CODE>, call
-<A NAME="lua_close"></A>
+(global variables, stack, etc.)
+is stored in a dynamically allocated structure of type <code>lua_State</code>.
+
+A pointer to this state must be passed as the first argument to
+every function in the library, except to <code>lua_open</code>,
+which creates a Lua state from scratch.
+
+<p>Before calling any API function,
+you must create a state by calling <code>lua_open</code>:
+<PRE>
+       lua_State *lua_open (void);
+</PRE>
+
+
+<p>To release a state created with <code>lua_open</code>, call <code>lua_close</code>:
 <PRE>
        void lua_close (lua_State *L);
 </PRE>
-This function destroys all objects in the given Lua environment
-(calling the corresponding garbage-collection tag methods, if any)
+
+This function destroys all objects in the given Lua state
+(calling the corresponding garbage-collection metamethods, if any)
 and frees all dynamic memory used by that state.
-Usually, you do not need to call this function,
-because all resources are naturally released when your program ends.
+On several platforms, you may not need to call this function,
+because all resources are naturally released when the host program ends.
 On the other hand,
-long-running programs -
-like a daemon or a web server -
+long-running programs,
+such as a daemon or a web server,
 might need to release states as soon as they are not needed,
-to avoid growing too big.
-<P>
-With the exception of <CODE>lua_open</CODE>,
-all functions in the Lua API need a state as their first argument.
-<P>
-<P>
-<A NAME="5.2"></A>
-<H2>5.2 - The Stack and Indices</H2>
-<P>
-Lua uses a <EM>stack</EM> to pass values to and from C.
+to avoid growing too large.
+
+<p><h2>3.2 - The Stack and Indices</h2>
+
+<p>Lua uses a <em>virtual stack</em> to pass values to and from C.
 Each element in this stack represents a Lua value
-(nil, number, string, etc.).
-<P>
-For convenience,
+(<B>nil</B>, number, string, etc.).
+
+<p>Whenever Lua calls C, the called function gets a new stack,
+which is independent of previous stacks and of stacks of
+C functions that are still active.
+That stack initially contains any arguments to the C function,
+and it is where the C function pushes its results (see <a href="#LuacallC">3.16</a>)
+to be returned to the caller.
+
+<p>For convenience,
 most query operations in the API do not follow a strict stack discipline.
-Instead, they can refer to any element in the stack by using an <EM>index</EM>:
-A positive index represents an <EM>absolute</EM> stack position
-(starting at&nbsp;1, not 0 as in C);
-a negative index represents an <EM>offset</EM> from the top of the stack.
-More specifically, if the stack has <EM>n</EM> elements,
-index&nbsp;1 represents the first element
-(that is, the first element pushed onto the stack),
+Instead, they can refer to any element in the stack by using an <em>index</em>:
+A positive index represents an <em>absolute</em> stack position
+(starting at&nbsp;1);
+a negative index represents an <em>offset</em> from the top of the stack.
+More specifically, if the stack has <em>n</em> elements,
+then index&nbsp;1 represents the first element
+(that is, the element that was pushed onto the stack first)
 and
-index&nbsp;<EM>n</EM> represents the last element;
-index&nbsp;<I>-1</I> also represents the last element
-(that is, the element at the top),
-and index <I>-n</I> represents the first element.
-We say that an index is <EM>valid</EM>
-if it lays between&nbsp;1 and the stack top
-(that is, if <CODE>1 &lt;= abs(index) &lt;= top</CODE>).
-<A NAME="stack index"></A> <A NAME="valid index"></A>
-<P>
-At any time, you can get the index of the top element by calling
-<A NAME="lua_gettop"></A>
+index&nbsp;<em>n</em> represents the last element;
+index&nbsp;<em>-1</em> also represents the last element
+(that is, the element at the top)
+and index <em>-n</em> represents the first element.
+We say that an index is <em>valid</em>
+if it lies between&nbsp;1 and the stack top
+(that is, if <code>1 &#060;= abs(index) &#060;= top</code>).
+ 
+
+<p>At any time, you can get the index of the top element by calling
+<code>lua_gettop</code>:
 <PRE>
        int lua_gettop (lua_State *L);
 </PRE>
 Because indices start at&nbsp;1,
-the result of <CODE>lua_gettop</CODE> is equal to the number of elements in the stack
+the result of <code>lua_gettop</code> is equal to the number of elements in the stack
 (and so 0&nbsp;means an empty stack).
-<P>
-When you interact with Lua API,
-<EM>you are responsible for controlling stack overflow</EM>.
-The function <A NAME="lua_stackspace"></A>
-<PRE>
-       int lua_stackspace (lua_State *L);
-</PRE>
-returns the number of stack positions still available.
-Whenever Lua calls C, <A NAME="LUA_MINSTACK"></A>
-it ensures that
-at least <CODE>LUA_MINSTACK</CODE> positions are still available.
-<CODE>LUA_MINSTACK</CODE> is defined in <CODE>lua.h</CODE> and is at least&nbsp;16,
-and so you have to worry about stack space only
-when your code has loops pushing elements onto the stack.
-<P>
-Most query functions accept as indices any value inside the
-available stack space.
-Such indices are called <EM>acceptable indices</EM>.
-More formally, we can define an <A NAME="acceptable index"><EM>acceptable index</EM></A>
-as
-<PRE>
-     (index &lt; 0 &amp;&amp; abs(index) &lt;= top) || (index &gt; 0 &amp;&amp; index &lt;= top + stackspace)
-</PRE>
-Note that 0 is not an acceptable index.
-<P>
-<A NAME="5.3"></A>
-<H2>5.3 - Stack Manipulation</H2>
+
+<p>When you interact with Lua API,
+<em>you are responsible for controlling stack overflow</em>.
+The function
+<PRE>
+       int lua_checkstack (lua_State *L, int extra);
+</PRE>
+
+grows the stack size to <code>top + extra</code> elements;
+it returns false if it cannot grow the stack to that size.
+This function never shrinks the stack;
+if the stack is already larger than the new size,
+it is left unchanged.
+
+<p>Whenever Lua calls C, 
+it ensures that at least <code>LUA_MINSTACK</code> positions are available.
+<code>LUA_MINSTACK</code> is defined in <code>lua.h</code> as 20,
+so that usually you do not have to worry about stack space
+unless your code has loops pushing elements onto the stack.
+
+<p>Most query functions accept as indices any value inside the
+available stack space, that is, indices up to the maximum stack size
+you have set through <code>lua_checkstack</code>.
+Such indices are called <em>acceptable indices</em>.
+More formally, we define an <em>acceptable index</em>
+as follows:
+<PRE>
+     (index &#060; 0 &#038;&#038; abs(index) &#060;= top) || (index > 0 &#038;&#038; index &#060;= stackspace)
+</PRE>
+Note that 0 is never an acceptable index.
+
+<p>Unless otherwise noted,
+any function that accepts valid indices can also be called with
+<em>pseudo-indices</em>,
+which represent some Lua values that are accessible to the C&nbsp;code
+but are not in the stack.
+Pseudo-indices are used to access the global environment,
+the registry, and the upvalues of a C&nbsp;function (see <a href="#c-closure">3.17</a>).
+
+<p><h2>3.3 - Stack Manipulation</h2>
 The API offers the following functions for basic stack manipulation:
-<A NAME="lua_settop"></A><A NAME="lua_pushvalue"></A>
-<A NAME="lua_remove"></A><A NAME="lua_insert"></A>
 <PRE>
        void lua_settop    (lua_State *L, int index);
        void lua_pushvalue (lua_State *L, int index);
        void lua_remove    (lua_State *L, int index);
        void lua_insert    (lua_State *L, int index);
+       void lua_replace   (lua_State *L, int index);
 </PRE>
-<P>
-<CODE>lua_settop</CODE> accepts any acceptable index,
+
+
+
+<p><code>lua_settop</code> accepts any acceptable index,
 or 0,
 and sets the stack top to that index.
 If the new top is larger than the old one,
 then the new elements are filled with <B>nil</B>.
-If <CODE>index</CODE> is 0, then all stack elements are removed.
-A useful macro defined in the API is
+If <code>index</code> is 0, then all stack elements are removed.
+A useful macro defined in the <code>lua.h</code> is
 <PRE>
-       #define lua_pop(L,n) lua_settop(L, -(n)-1)
+       #define lua_pop(L,n)   lua_settop(L, -(n)-1)
 </PRE>
-which pops <CODE>n</CODE> elements from the stack.
-<P>
-<CODE>lua_pushvalue</CODE> pushes onto the stack a <EM>copy</EM> of the element
+
+which pops <code>n</code> elements from the stack.
+
+<p><code>lua_pushvalue</code> pushes onto the stack a copy of the element
 at the given index.
-<CODE>lua_remove</CODE> removes the element at the given position,
-shifting down the elements on top of that position to fill in the gap.
-<CODE>lua_insert</CODE> moves the top element into the given position,
-shifting up the elements on top of that position to open space.
-These functions accept only valid indices.
-As an example, if the stack starts as <CODE>10 20 30 40 50</CODE>
-(from bottom to top),
+<code>lua_remove</code> removes the element at the given position,
+shifting down the elements above that position to fill the gap.
+<code>lua_insert</code> moves the top element into the given position,
+shifting up the elements above that position to open space.
+<code>lua_replace</code> moves the top element into the given position,
+without shifting any element (therefore replacing the value at
+the given position).
+All these functions accept only valid indices.
+(You cannot call <code>lua_remove</code> or <code>lua_insert</code> with
+pseudo-indices, as they do not represent a stack position.)
+
+<p>As an example, if the stack starts as <code>10 20 30 40 50*</code>
+(from bottom to top; the `<code>*</code>&acute; marks the top),
 then
 <PRE>
-       lua_pushvalue(L, 3)    --&gt; 10 20 30 40 50 30
-       lua_pushvalue(L, -1)   --&gt; 10 20 30 40 50 30 30
-       lua_remove(L, -3)      --&gt; 10 20 30 40 30 30
-       lua_remove(L,  6)      --&gt; 10 20 30 40 30
-       lua_insert(L,  1)      --&gt; 30 10 20 30 40
-       lua_insert(L, -1)      --&gt; 30 10 20 30 40  (no effect)
-       lua_settop(L, -3)      --&gt; 30 10 20
-       lua_settop(L, 6)       --&gt; 30 10 20 nil nil nil
-</PRE>
-<P>
-<P>
-<A NAME="5.4"></A>
-<H2>5.4 - Querying the Stack</H2>
-<P>
-To check the type of a stack element,
+       lua_pushvalue(L, 3)    --> 10 20 30 40 50 30*
+       lua_pushvalue(L, -1)   --> 10 20 30 40 50 30 30*
+       lua_remove(L, -3)      --> 10 20 30 40 30 30*
+       lua_remove(L,  6)      --> 10 20 30 40 30*
+       lua_insert(L,  1)      --> 30 10 20 30 40*
+       lua_insert(L, -1)      --> 30 10 20 30 40*  (no effect)
+       lua_replace(L, 2)      --> 30 40 20 30*
+       lua_settop(L, -3)      --> 30 40*
+       lua_settop(L,  6)      --> 30 40 nil nil nil nil*
+</PRE>
+
+<p><h2>3.4 - Querying the Stack</h2>
+
+<p>To check the type of a stack element,
 the following functions are available:
-<A NAME="lua_type"></A><A NAME="lua_tag"></A>
-<A NAME="lua_isnil"></A><A NAME="lua_isnumber"></A><A NAME="lua_isstring"></A>
-<A NAME="lua_istable"></A>
-<A NAME="lua_isfunction"></A><A NAME="lua_iscfunction"></A><A NAME="lua_isuserdata"></A>
-<PRE>
-       int         lua_type        (lua_State *L, int index);
-       int         lua_tag         (lua_State *L, int index);
-       int         lua_isnil       (lua_State *L, int index);
-       int         lua_isnumber    (lua_State *L, int index);
-       int         lua_isstring    (lua_State *L, int index);
-       int         lua_istable     (lua_State *L, int index);
-       int         lua_isfunction  (lua_State *L, int index);
-       int         lua_iscfunction (lua_State *L, int index);
-       int         lua_isuserdata  (lua_State *L, int index);
+<PRE>
+       int lua_type            (lua_State *L, int index);
+       int lua_isnil           (lua_State *L, int index);
+       int lua_isboolean       (lua_State *L, int index);
+       int lua_isnumber        (lua_State *L, int index);
+       int lua_isstring        (lua_State *L, int index);
+       int lua_istable         (lua_State *L, int index);
+       int lua_isfunction      (lua_State *L, int index);
+       int lua_iscfunction     (lua_State *L, int index);
+       int lua_isuserdata      (lua_State *L, int index);
+       int lua_islightuserdata (lua_State *L, int index);
 </PRE>
+
+
+
+
+
 These functions can be called with any acceptable index.
-<P>
-<CODE>lua_type</CODE> returns one of the following constants,
-according to the type of the given object:
-<CODE>LUA_TNIL</CODE>,
-<CODE>LUA_TNUMBER</CODE>,
-<CODE>LUA_TSTRING</CODE>,
-<CODE>LUA_TTABLE</CODE>,
-<CODE>LUA_TFUNCTION</CODE>,
-<CODE>LUA_TUSERDATA</CODE>.
-If the index is non-valid
-(that is, if that stack position is ``empty''),
-then <CODE>lua_type</CODE> returns <CODE>LUA_TNONE</CODE>.
-These constants can be converted to strings with
-<A NAME="lua_typename"></A>
-<PRE>
-       const char *lua_typename (lua_State *L, int t);
-</PRE>
-where <CODE>t</CODE> is a type returned by <CODE>lua_type</CODE>.
-The strings returned by <CODE>lua_typename</CODE> are
-<CODE>"nil"</CODE>, <CODE>"number"</CODE>, <CODE>"string"</CODE>, <CODE>"table"</CODE>,
-<CODE>"function"</CODE>, <CODE>"userdata"</CODE>, and <CODE>"no value"</CODE>,
-<P>
-<CODE>lua_tag</CODE> returns the tag of a value,
-or <CODE>LUA_NOTAG</CODE> for a non-valid index.
-<P>
-The <CODE>lua_is*</CODE> functions return&nbsp;1 if the object is compatible
+
+<p><code>lua_type</code> returns the type of a value in the stack,
+or <code>LUA_TNONE</code> for a non-valid index
+(that is, if that stack position is "empty").
+The types returned by <code>lua_type</code> are coded by the following constants
+defined in <code>lua.h</code>:
+<code>LUA_TNIL</code>,
+<code>LUA_TNUMBER</code>,
+<code>LUA_TBOOLEAN</code>,
+<code>LUA_TSTRING</code>,
+<code>LUA_TTABLE</code>,
+<code>LUA_TFUNCTION</code>,
+<code>LUA_TUSERDATA</code>,
+<code>LUA_TTHREAD</code>,
+<code>LUA_TLIGHTUSERDATA</code>.
+The following function translates these constants to strings:
+<PRE>
+       const char *lua_typename  (lua_State *L, int type);
+</PRE>
+
+
+<p>The <code>lua_is*</code> functions return&nbsp;1 if the object is compatible
 with the given type, and 0 otherwise.
+<code>lua_isboolean</code> is an exception to this rule:
+It succeeds only for boolean values
+(otherwise it would be useless,
+as any value has a boolean value).
 They always return 0 for a non-valid index.
-<CODE>lua_isnumber</CODE> accepts numbers and numerical strings,
-<CODE>lua_isstring</CODE> accepts strings and numbers (see Section&nbsp;<A HREF="#coercion">4.2</A>),
-and <CODE>lua_isfunction</CODE> accepts both Lua functions and C&nbsp;functions.
+<code>lua_isnumber</code> accepts numbers and numerical strings;
+<code>lua_isstring</code> accepts strings and numbers (see <a href="#coercion">2.2.1</a>);
+<code>lua_isfunction</code> accepts both Lua functions and C&nbsp;functions;
+and <code>lua_isuserdata</code> accepts both full and light userdata.
 To distinguish between Lua functions and C&nbsp;functions,
-you should use <CODE>lua_iscfunction</CODE>.
+you can use <code>lua_iscfunction</code>.
+To distinguish between full and light userdata,
+you can use <code>lua_islightuserdata</code>.
 To distinguish between numbers and numerical strings,
-you can use <CODE>lua_type</CODE>.
-<P>
-The API also has functions to compare two values in the stack:
-<A NAME="lua_equal"></A>
-<A NAME="lua_lessthan"></A>
+you can use <code>lua_type</code>.
+
+<p>The API also contains functions to compare two values in the stack:
 <PRE>
        int lua_equal    (lua_State *L, int index1, int index2);
+       int lua_rawequal (lua_State *L, int index1, int index2);
        int lua_lessthan (lua_State *L, int index1, int index2);
 </PRE>
-These functions are equivalent to their counterparts in Lua.
-Specifically, <CODE>lua_lessthan</CODE> is equivalent to the <CODE>lt_event</CODE>
-described in Section&nbsp;<A HREF="#tag-method">4.8</A>.
-Both functions return 0 if any of the indices are non-valid.
-<P>
-To translate a value in the stack to a specific C&nbsp;type,
+
+<code>lua_equal</code> and <code>lua_lessthan</code>
+are equivalent to their counterparts in Lua (see <a href="#rel-ops">2.5.2</a>).
+<code>lua_rawequal</code> compares the values for primitive equality,
+without metamethods.
+These functions return 0 (false) if any of the indices are non-valid.
+
+<p><a name="lua-to"><h2>3.5 - Getting Values from the Stack</h2></a>
+
+<p>To translate a value in the stack to a specific C&nbsp;type,
 you can use the following conversion functions:
-<A NAME="lua_tonumber"></A><A NAME="lua_tostring"></A><A NAME="lua_strlen"></A>
-<A NAME="lua_tocfunction"></A><A NAME="lua_touserdata"></A>
 <PRE>
-       double         lua_tonumber    (lua_State *L, int index);
+       int            lua_toboolean   (lua_State *L, int index);
+       lua_Number     lua_tonumber    (lua_State *L, int index);
        const char    *lua_tostring    (lua_State *L, int index);
        size_t         lua_strlen      (lua_State *L, int index);
        lua_CFunction  lua_tocfunction (lua_State *L, int index);
        void          *lua_touserdata  (lua_State *L, int index);
+       lua_State     *lua_tothread    (lua_State *L, int index);
+       void          *lua_topointer   (lua_State *L, int index);
 </PRE>
+
+
+
 These functions can be called with any acceptable index.
 When called with a non-valid index,
 they act as if the given value had an incorrect type.
-<P>
-<CODE>lua_tonumber</CODE> converts the value at the given index
-to a floating-point number.
-This value must be a number or a string convertible to number
-(see Section&nbsp;<A HREF="#coercion">4.2</A>); otherwise, <CODE>lua_tonumber</CODE> returns&nbsp;0.
-<P>
-<CODE>lua_tostring</CODE> converts a Lua value to a string
-(<CODE>const char*</CODE>).
-This value must be a string or a number;
-otherwise, the function returns <CODE>NULL</CODE>.
-This function returns a pointer to a string inside the Lua environment.
-Those strings always have a zero (<CODE>'\0'</CODE>) after their last character (as in C),
-but may contain other zeros in their body.
+
+<p><code>lua_toboolean</code> converts the Lua value at the given index
+to a C "boolean" value (0&nbsp;or&nbsp;1).
+Like all tests in Lua, <code>lua_toboolean</code> returns 1 for any Lua value
+different from <B>false</B> and <B>nil</B>;
+otherwise it returns 0.
+It also returns 0 when called with a non-valid index.
+(If you want to accept only real boolean values,
+use <code>lua_isboolean</code> to test the type of the value.)
+
+<p><code>lua_tonumber</code> converts the Lua value at the given index
+to a number (by default, <code>lua_Number</code> is <code>double</code>).
+
+The Lua value must be a number or a string convertible to number
+(see <a href="#coercion">2.2.1</a>); otherwise, <code>lua_tonumber</code> returns&nbsp;0.
+
+<p><code>lua_tostring</code> converts the Lua value at the given index to a string
+(<code>const char*</code>).
+The Lua value must be a string or a number;
+otherwise, the function returns <code>NULL</code>.
+If the value is a number,
+then <code>lua_tostring</code> also
+<em>changes the actual value in the stack to a string</em>.
+(This change confuses <code>lua_next</code>
+when <code>lua_tostring</code> is applied to keys.)
+<code>lua_tostring</code> returns a fully aligned pointer
+to a string inside the Lua state.
+This string always has a zero (<code>'\0'</code>)
+after its last character (as in&nbsp;C),
+but may contain other zeros in its body.
 If you do not know whether a string may contain zeros,
-you should use <CODE>lua_strlen</CODE> to get its actual length.
+you can use <code>lua_strlen</code> to get its actual length.
 Because Lua has garbage collection,
-there is no guarantee that the pointer returned by <CODE>lua_tostring</CODE>
-will be valid after the respective value is removed from the stack.
-<P>
-<CODE>lua_tocfunction</CODE> converts a value in the stack to a C&nbsp;function.
+there is no guarantee that the pointer returned by <code>lua_tostring</code>
+will be valid after the corresponding value is removed from the stack.
+If you need the string after the current function returns,
+then you should duplicate it or put it into the registry (see <a href="#registry">3.18</a>).
+
+<p><code>lua_tocfunction</code> converts a value in the stack to a C&nbsp;function.
 This value must be a C&nbsp;function;
-otherwise, <CODE>lua_tocfunction</CODE> returns <CODE>NULL</CODE>.
-The type <CODE>lua_CFunction</CODE> is explained in Section&nbsp;<A HREF="#LuacallC">5.13</A>.
-<P>
-<CODE>lua_touserdata</CODE> converts a value to <CODE>void*</CODE>.
-This value must have type <EM>userdata</EM>;
-otherwise, <CODE>lua_touserdata</CODE> returns <CODE>NULL</CODE>.
-<P>
-<P>
-<P>
-<A NAME="5.5"></A>
-<H2>5.5 - Pushing values onto the Stack</H2>
-<P>
-The API has the following functions to
+otherwise, <code>lua_tocfunction</code> returns <code>NULL</code>.
+The type <code>lua_CFunction</code> is explained in <a href="#LuacallC">3.16</a>.
+
+<p><code>lua_tothread</code> converts a value in the stack to a Lua thread
+(represented as <code>lua_State *</code>).
+This value must be a thread;
+otherwise, <code>lua_tothread</code> returns <code>NULL</code>.
+
+<p><code>lua_topointer</code> converts a value in the stack to a generic
+C pointer (<code>void *</code>).
+The value may be a userdata, a table, a thread, or a function;
+otherwise, <code>lua_topointer</code> returns <code>NULL</code>.
+Lua ensures that different objects of the
+same type return different pointers.
+There is no direct way to convert the pointer back to its original value.
+Typically this function is used for debug information.
+
+<p><code>lua_touserdata</code> is explained in <a href="#userdata">3.8</a>.
+
+<p><a name="pushing"><h2>3.6 - Pushing Values onto the Stack</h2></a>
+
+<p>The API has the following functions to
 push C&nbsp;values onto the stack:
-<A NAME="lua_pushnumber"></A><A NAME="lua_pushlstring"></A><A NAME="lua_pushstring"></A>
-<A NAME="lua_pushcfunction"></A><A NAME="lua_pushusertag"></A>
-<A NAME="pushing"></A>
-<A NAME="lua_pushnil"></A><A NAME="lua_pushuserdata"></A>
-<PRE>
-       void lua_pushnumber    (lua_State *L, double n);
-       void lua_pushlstring   (lua_State *L, const char *s, size_t len);
-       void lua_pushstring    (lua_State *L, const char *s);
-       void lua_pushusertag   (lua_State *L, void *u, int tag);
-       void lua_pushnil       (lua_State *L);
-       void lua_pushcfunction (lua_State *L, lua_CFunction f);
+<PRE>
+       void lua_pushboolean       (lua_State *L, int b);
+       void lua_pushnumber        (lua_State *L, lua_Number n);
+       void lua_pushlstring       (lua_State *L, const char *s, size_t len);
+       void lua_pushstring        (lua_State *L, const char *s);
+       void lua_pushnil           (lua_State *L);
+       void lua_pushcfunction     (lua_State *L, lua_CFunction f);
+       void lua_pushlightuserdata (lua_State *L, void *p);
 </PRE>
+
+<p>
+
+
 These functions receive a C&nbsp;value,
 convert it to a corresponding Lua value,
 and push the result onto the stack.
-In particular, <CODE>lua_pushlstring</CODE> and <CODE>lua_pushstring</CODE>
-make an <EM>internal copy</EM> of the given string.
-<CODE>lua_pushstring</CODE> can only be used to push proper C&nbsp;strings
+In particular, <code>lua_pushlstring</code> and <code>lua_pushstring</code>
+make an internal copy of the given string.
+<code>lua_pushstring</code> can only be used to push proper C&nbsp;strings
 (that is, strings that end with a zero and do not contain embedded zeros);
-otherwise you should use the more general <CODE>lua_pushlstring</CODE>,
+otherwise, you should use the more general <code>lua_pushlstring</code>,
 which accepts an explicit size.
-<P>
-<P>
-<A NAME="GC"></A>
-<A NAME="5.6"></A>
-<H2>5.6 - Garbage Collection</H2>
-<P>
-Lua uses two numbers to control its garbage collection.
-One number counts how many bytes of dynamic memory Lua is using,
-and the other is a threshold.
-(This internal byte counter kept by Lua is not completely acurate;
-it is just a lower bound, usually within&nbsp;10% of the correct value.)
-When the number of bytes crosses the threshold,
-Lua runs a garbage-collection cycle,
-which reclaims the memory of all ``dead'' objects
-(that is, objects no longer accessible from Lua).
-The byte counter is corrected,
-and then the threshold is reset to twice the value of the byte counter.
-<P>
-You can access the current values of these two numbers through the
+
+<p>You can also push "formatted" strings:
+<PRE>
+       const char *lua_pushfstring  (lua_State *L, const char *fmt, ...);
+       const char *lua_pushvfstring (lua_State *L, const char *fmt,
+                                                   va_list argp);
+</PRE>
+
+These functions push onto the stack a formatted string
+and return a pointer to that string.
+They are similar to <code>sprintf</code> and <code>vsprintf</code>,
+but with some important differences:
+<ul>
+<li> You do not have to allocate the space for the result:
+The result is a Lua string and Lua takes care of memory allocation
+(and deallocation, through garbage collection).
+<li> The conversion specifiers are quite restricted.
+There are no flags, widths, or precisions.
+The conversion specifiers can be simply
+`<code>%%</code>&acute; (inserts a `<code>%</code>&acute; in the string),
+`<code>%s</code>&acute; (inserts a zero-terminated string, with no size restrictions),
+`<code>%f</code>&acute; (inserts a <code>lua_Number</code>),
+`<code>%d</code>&acute; (inserts an <code>int</code>), and
+`<code>%c</code>&acute; (inserts an <code>int</code> as a character).
+</ul>
+
+<p>The function
+<PRE>
+       void lua_concat (lua_State *L, int n);
+</PRE>
+
+concatenates the <code>n</code> values at the top of the stack,
+pops them, and leaves the result at the top.
+If <code>n</code> is 1, the result is that single string
+(that is, the function does nothing);
+if <code>n</code> is 0, the result is the empty string.
+Concatenation is done following the usual semantics of Lua
+(see <a href="#concat">2.5.4</a>).
+
+<p><a name="GC-API"><h2>3.7 - Controlling Garbage Collection</h2></a>
+
+<p>Lua uses two numbers to control its garbage collection:
+the <em>count</em> and the <em>threshold</em> (see <a href="#GC">2.9</a>).
+The first counts the amount of memory in use by Lua;
+when the count reaches the threshold,
+Lua runs its garbage collector.
+After the collection, the count is updated
+and the threshold  is set to twice the count value.
+
+<p>You can access the current values of these two numbers through the
 following functions:
-<A NAME="lua_getgcthreshold"></A> <A NAME="lua_getgccount"></A>
 <PRE>
        int  lua_getgccount (lua_State *L);
        int  lua_getgcthreshold (lua_State *L);
 </PRE>
+ 
 Both return their respective values in Kbytes.
 You can change the threshold value with
-<A NAME="lua_setgcthreshold"></A>
 <PRE>
        void  lua_setgcthreshold (lua_State *L, int newthreshold);
 </PRE>
-Again, the <CODE>newthreshold</CODE> value is given in Kbytes.
+
+Again, the <code>newthreshold</code> value is given in Kbytes.
 When you call this function,
 Lua sets the new threshold and checks it against the byte counter.
-If the new threshold is smaller than the byte counter,
-then Lua immediately runs the garbage collector;
-after the collection, 
+If the new threshold is less than the byte counter,
+then Lua immediately runs the garbage collector.
+In particular
+<code>lua_setgcthreshold(L,0)</code> forces a garbage collection.
+After the collection,
 a new threshold is set according to the previous rule.
-<P>
-If you want to change the adaptative behavior of the garbage collector,
-you can use the garbage-collection tag method for <B>nil</B> 
-to set your own threshold
-(the tag method is called after Lua resets the threshold).
-<P>
-<P>
-<A NAME="C-tags"></A>
-<A NAME="5.7"></A>
-<H2>5.7 - Userdata and Tags</H2>
-<P>
-Because userdata are objects,
-the function <CODE>lua_pushusertag</CODE> may create a new userdata.
-If Lua has a userdata with the given value (<CODE>void*</CODE>) and tag,
-then that userdata is pushed.
-Otherwise, a new userdata is created, with the given value and tag.
-If this function is called with
-<CODE>tag</CODE> equal to <CODE>LUA_ANYTAG</CODE><A NAME="LUA_ANYTAG"></A>,
-then Lua will try to find any userdata with the given value,
-regardless of its tag.
-If there is no userdata with that value, then a new one is created,
-with tag equal to 0.
-<P>
-Userdata can have different tags,
-whose semantics are only known to the host program.
-Tags are created with the function
-<A NAME="lua_newtag"></A>
-<PRE>
-       int lua_newtag (lua_State *L);
-</PRE>
-The function <CODE>lua_settag</CODE> changes the tag of
-the object on top of the stack (without popping it):
-<A NAME="lua_settag"></A>
-<PRE>
-       void lua_settag (lua_State *L, int tag);
-</PRE>
-The object must be a userdata or a table;
-the given <CODE>tag</CODE> must be a value created with <CODE>lua_newtag</CODE>.
-<P>
-<A NAME="luado"></A>
-<A NAME="5.8"></A>
-<H2>5.8 - Executing Lua Code</H2>
-A host program can execute Lua chunks written in a file or in a string
-by using the following functions:
-<A NAME="lua_dofile"></A><A NAME="lua_dostring"></A><A NAME="lua_dobuffer"></A>
-<PRE>
-       int lua_dofile   (lua_State *L, const char *filename);
-       int lua_dostring (lua_State *L, const char *string);
-       int lua_dobuffer (lua_State *L, const char *buff,
-                         size_t size, const char *name);
-</PRE>
-These functions return
-0 in case of success, or one of the following error codes if they fail:
-<UL>
-<LI><A NAME="LUA_ERRRUN"><TT>LUA_ERRRUN</TT></A> -
-error while running the chunk.
-<LI><A NAME="LUA_ERRSYNTAX"><TT>LUA_ERRSYNTAX</TT></A> -
+
+<p><a name="userdata"><h2>3.8 - Userdata</h2></a>
+
+<p>Userdata represents C values in Lua.
+Lua supports two types of userdata:
+<em>full userdata</em> and <em>light userdata</em>.
+
+<p>A full userdata represents a block of memory.
+It is an object (like a table):
+You must create it, it can have its own metatable,
+and you can detect when it is being collected.
+A full userdata is only equal to itself (under raw equality).
+
+<p>A light userdata represents a pointer.
+It is a value (like a number):
+You do not create it, it has no metatables,
+it is not collected (as it was never created).
+A light userdata is equal to "any"
+light userdata with the same C address.
+
+<p>In Lua code, there is no way to test whether a userdata is full or light;
+both have type <code>userdata</code>.
+In C code, <code>lua_type</code> returns <code>LUA_TUSERDATA</code> for full userdata,
+and <code>LUA_TLIGHTUSERDATA</code> for light userdata.
+
+<p>You can create a new full userdata with the following function:
+<PRE>
+       void *lua_newuserdata (lua_State *L, size_t size);
+</PRE>
+
+This function allocates a new block of memory with the given size,
+pushes on the stack a new userdata with the block address,
+and returns this address.
+
+<p>To push a light userdata into the stack you use
+<code>lua_pushlightuserdata</code> (see <a href="#pushing">3.6</a>).
+
+<p><code>lua_touserdata</code> (see <a href="#lua-to">3.5</a>) retrieves the value of a userdata.
+When applied on a full userdata, it returns the address of its block;
+when applied on a light userdata, it returns its pointer;
+when applied on a non-userdata value, it returns <code>NULL</code>.
+
+<p>When Lua collects a full userdata,
+it calls the userdata's <code>gc</code> metamethod, if any,
+and then it frees the userdata's corresponding memory.
+
+<p><h2>3.9 - Metatables</h2>
+
+<p>The following functions allow you to manipulate the metatables
+of an object:
+<PRE>
+       int lua_getmetatable (lua_State *L, int index);
+       int lua_setmetatable (lua_State *L, int index);
+</PRE>
+
+<code>lua_getmetatable</code> pushes on the stack the metatable of a given object.
+If the index is not valid,
+or if the object does not have a metatable,
+<code>lua_getmetatable</code> returns 0 and pushes nothing on the stack.
+
+<p><code>lua_setmetatable</code> pops a table from the stack and
+sets it as the new metatable for the given object.
+<code>lua_setmetatable</code> returns 0 when it cannot
+set the metatable of the given object
+(that is, when the object is neither a userdata nor a table);
+even then it pops the table from the stack.
+
+<p><h2>3.10 - Loading Lua Chunks</h2>
+
+<p>You can load a Lua chunk with <code>lua_load</code>:
+<PRE>
+       typedef const char * (*lua_Chunkreader)
+                                (lua_State *L, void *data, size_t *size);
+
+       int lua_load (lua_State *L, lua_Chunkreader reader, void *data,
+                                   const char *chunkname);
+</PRE>
+
+The return values of <code>lua_load</code> are:
+<ul>
+<li> 0 --- no errors;
+<li> <code>LUA_ERRSYNTAX</code> ---
 syntax error during pre-compilation.
-<LI><A NAME="LUA_ERRMEM"><TT>LUA_ERRMEM</TT></A> -
+<li> <code>LUA_ERRMEM</code> ---
 memory allocation error.
-For such errors, Lua does not call <CODE>_ERRORMESSAGE</CODE> (see Section&nbsp;<A HREF="#error">4.7</A>).
-<LI><A NAME="LUA_ERRERR"><TT>LUA_ERRERR</TT></A> -
-error while running <CODE>_ERRORMESSAGE</CODE>.
-For such errors, Lua does not call <CODE>_ERRORMESSAGE</CODE> again, to avoid loops.
-<LI><A NAME="LUA_ERRFILE"><TT>LUA_ERRFILE</TT></A> -
-error opening the file (only for <CODE>lua_dofile</CODE>).
-In this case,
-you may want to
-check <CODE>errno</CODE>,
-call <CODE>strerror</CODE>,
-or call <CODE>perror</CODE> to tell the user what went wrong.
-</UL>
-These constants are defined in <CODE>lua.h</CODE>.
-<P>
-When called with argument <CODE>NULL</CODE>,
-<CODE>lua_dofile</CODE> executes the <CODE>stdin</CODE> stream.
-<CODE>lua_dofile</CODE> and <CODE>lua_dobuffer</CODE>
-are both able to execute pre-compiled chunks.
-They automatically detect whether the chunk is text or binary,
-and load it accordingly (see program <A NAME="luac"><TT><A HREF="luac.html">luac</A></TT></A>).
-<CODE>lua_dostring</CODE> executes only source code,
-given in textual form.
-<P>
-The third parameter to <CODE>lua_dobuffer</CODE>
-is the ``name of the chunk'',
-which is used in error messages and debug information.
-If <CODE>name</CODE> is <CODE>NULL</CODE>,
-then Lua gives a default name to the chunk.
-<P>
-These functions push onto the stack
-any values eventually returned by the chunk.
-A chunk may return any number of values;
-Lua takes care that these values fit into the stack space,
-but after the call the responsibility is back to you.
-If you need to push other elements after calling any of these functions,
-and you want to ``play safe'',
-you must either check the stack space
-with <CODE>lua_stackspace</CODE>
-or remove the returned elements
-from the stack (if you do not need them).
-For instance, the following code
-loads a chunk in a file and discards all results returned by this chunk,
-leaving the stack as it was before the call:
-<PRE>
-      {
-       int oldtop = lua_gettop(L);
-       lua_dofile(L, filename);
-       lua_settop(L, oldtop);
-      }
-</PRE>
-<P>
-<P>
-<A NAME="5.9"></A>
-<H2>5.9 - Manipulating Global Variables in Lua</H2>
-<P>
-To read the value of a global Lua variable,
-you call
-<A NAME="lua_getglobal"></A>
-<PRE>
-       void lua_getglobal (lua_State *L, const char *varname);
-</PRE>
-which pushes onto the stack the value of the given variable.
-As in Lua, this function may trigger a tag method
-for the ``getglobal'' event (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-To read the real value of a global variable,
-without invoking any tag method,
-use <CODE>lua_rawget</CODE> over the table of globals
-(see below).
-<P>
-To store a value in a global variable,
-you call
-<A NAME="lua_setglobal"></A>
-<PRE>
-       void lua_setglobal (lua_State *L, const char *varname);
-</PRE>
-which pops from the stack the value to be stored in the given variable.
-As in Lua, this function may trigger a tag method
-for the ``setglobal'' event (see Section&nbsp;<A HREF="#tag-method">4.8</A>).
-To set the real value of a global variable,
-without invoking any tag method,
-use <CODE>lua_rawset</CODE> over the table of globals
-(see below).
-<P>
-All global variables are kept in an ordinary Lua table.
-You can get this table calling
-<A NAME="lua_getglobals"></A>
-<PRE>
-       void lua_getglobals (lua_State *L);
-</PRE>
-which pushes the current table of globals onto the stack.
-To set another table as the table of globals,
-you call
-<A NAME="lua_setglobals"></A>
-<PRE>
-       void lua_setglobals (lua_State *L);
-</PRE>
-The table to be used is popped from the stack.
-<P>
-<A NAME="5.10"></A>
-<H2>5.10 - Manipulating Tables in Lua</H2>
-Lua tables can also be manipulated through the API.
-<P>
-To read the value of in a table,
-the table must reside somewhere in the stack.
-With this set,
-you call
-<A NAME="lua_gettable"></A>
+</ul>
+If there are no errors,
+<code>lua_load</code> pushes the compiled chunk as a Lua
+function on top of the stack.
+Otherwise, it pushes an error message.
+
+<p><code>lua_load</code> automatically detects whether the chunk is text or binary,
+and loads it accordingly (see program <code>luac</code>).
+
+<p><code>lua_load</code> uses an user-supplied <em>reader</em> function to read the chunk.
+Everytime it needs another piece of the chunk,
+it calls the reader,
+passing along its <code>data</code> parameter.
+The reader must return a pointer to a block of memory
+with a new piece of the chunk
+and set <code>size</code> to the block size.
+To signal the end of the chunk, the reader returns <code>NULL</code>.
+The reader function may return pieces of any size greater than zero.
+
+<p>In the current implementation,
+the reader function cannot call any Lua function;
+to ensure that, it always receives <code>NULL</code> as the Lua state.
+
+<p>The <em>chunkname</em> is used for error messages
+and debug information (see <a href="#debugI">4</a>).
+
+<p>See the auxiliary library (<code>lauxlib.c</code>)
+for examples of how to use <code>lua_load</code>
+and for some ready-to-use functions to load chunks
+from files and strings.
+
+<p><h2>3.11 - Manipulating Tables</h2>
+
+<p>Tables are created by calling
+the function
+<PRE>
+       void lua_newtable (lua_State *L);
+</PRE>
+
+This function creates a new, empty table and pushes it onto the stack.
+
+<p>To read a value from a table that resides somewhere in the stack,
+call
 <PRE>
        void lua_gettable (lua_State *L, int index);
 </PRE>
-where <CODE>index</CODE> refers to the table.
-<CODE>lua_gettable</CODE> pops a key from the stack,
+
+where <code>index</code> points to the table.
+<code>lua_gettable</code> pops a key from the stack
 and returns (on the stack) the contents of the table at that key.
-As in Lua, this operation may trigger a tag method
-for the ``gettable'' event.
+The table is left where it was in the stack.
+As in Lua, this function may trigger a metamethod
+for the "index" event (see <a href="#metatable">2.8</a>).
 To get the real value of any table key,
-without invoking any tag method,
-use the <EM>raw</EM> version:
-<A NAME="lua_rawget"></A>
+without invoking any metamethod,
+use the <em>raw</em> version:
 <PRE>
        void lua_rawget (lua_State *L, int index);
 </PRE>
-<P>
-To store a value into a table that resides somewhere in the stack,
-you push the key and the value onto the stack
-(in this order),
-and then call
-<A NAME="lua_settable"></A>
+
+
+<p>To store a value into a table that resides somewhere in the stack,
+you push the key and then the value onto the stack,
+and call
 <PRE>
        void lua_settable (lua_State *L, int index);
 </PRE>
-where <CODE>index</CODE> refers to the table.
-<CODE>lua_settable</CODE> pops from the stack both the key and the value.
-As in Lua, this operation may trigger a tag method
-for the ``settable'' event.
+
+where <code>index</code> points to the table.
+<code>lua_settable</code> pops from the stack both the key and the value.
+The table is left where it was in the stack.
+As in Lua, this operation may trigger a metamethod
+for the "settable" or "newindex" events.
 To set the real value of any table index,
-without invoking any tag method,
-use the <EM>raw</EM> version:
-<A NAME="lua_rawset"></A>
+without invoking any metamethod,
+use the <em>raw</em> version:
 <PRE>
        void lua_rawset (lua_State *L, int index);
 </PRE>
-<P>
-Finally, the function
-<A NAME="lua_newtable"></A>
+
+
+<p>You can traverse a table with the function
 <PRE>
-       void lua_newtable (lua_State *L);
+       int lua_next (lua_State *L, int index);
+</PRE>
+
+where <code>index</code> points to the table to be traversed.
+The function pops a key from the stack,
+and pushes a key-value pair from the table
+(the "next" pair after the given key).
+If there are no more elements, then <code>lua_next</code> returns 0
+(and pushes nothing).
+Use a <B>nil</B> key to signal the start of a traversal.
+
+<p>A typical traversal looks like this:
+<PRE>
+       /* table is in the stack at index `t' */
+       lua_pushnil(L);  /* first key */
+       while (lua_next(L, t) != 0) {
+         /* `key' is at index -2 and `value' at index -1 */
+         printf("%s - %s\n",
+           lua_typename(L, lua_type(L, -2)), lua_typename(L, lua_type(L, -1)));
+         lua_pop(L, 1);  /* removes `value'; keeps `key' for next iteration */
+       }
+</PRE>
+
+<p>While traversing a table,
+do not call <code>lua_tostring</code> directly on a key,
+unless you know that the key is actually a string.
+Recall that <code>lua_tostring</code> <em>changes</em> the value at the given index;
+this confuses the next call to <code>lua_next</code>.
+
+<p><a name="globals"><h2>3.12 - Manipulating Environments</h2></a>
+
+<p>All global variables are kept in ordinary Lua tables,
+called environments.
+The initial environment is called the global environment.
+This table is always at pseudo-index <code>LUA_GLOBALSINDEX</code>.
+
+<p>To access and change the value of global variables,
+you can use regular table operations over an environment table.
+For instance, to access the value of a global variable, do
+<PRE>
+       lua_pushstring(L, varname);
+       lua_gettable(L, LUA_GLOBALSINDEX);
+</PRE>
+
+<p>You can change the global environment of a Lua thread using <code>lua_replace</code>.
+
+<p>The following functions get and set the environment of Lua functions:
+<PRE>
+       void lua_getfenv (lua_State *L, int index);
+       int  lua_setfenv (lua_State *L, int index);
 </PRE>
-creates a new, empty table and pushes it onto the stack.
-<P>
-<A NAME="5.11"></A>
-<H2>5.11 - Using Tables as Arrays</H2>
+
+<code>lua_getfenv</code> pushes on the stack the environment table of
+the function at index <code>index</code> in the stack.
+If the function is a C function,
+<code>lua_getfenv</code> pushes the global environment.
+<code>lua_setfenv</code> pops a table from the stack and sets it as
+the new environment for the function at index <code>index</code> in the stack.
+If the object at the given index is not a Lua function,
+<code>lua_setfenv</code> returns 0.
+
+<p><h2>3.13 - Using Tables as Arrays</h2>
 The API has functions that help to use Lua tables as arrays,
 that is,
 tables indexed by numbers only:
-<A NAME="lua_rawgeti"></A>
-<A NAME="lua_rawseti"></A>
-<A NAME="lua_getn"></A>
 <PRE>
        void lua_rawgeti (lua_State *L, int index, int n);
        void lua_rawseti (lua_State *L, int index, int n);
-       int  lua_getn    (lua_State *L, int index);
-</PRE>
-<P>
-<CODE>lua_rawgeti</CODE> gets the value of the <EM>n</EM>-th element of the table
-at stack position <CODE>index</CODE>.
-<P>
-<CODE>lua_rawseti</CODE> sets the value of the <EM>n</EM>-th element of the table
-at stack position <CODE>index</CODE> to the value at the top of the stack.
-<P>
-<CODE>lua_getn</CODE> returns the number of elements in the table
-at stack position <CODE>index</CODE>.
-This number is the value of the table field <CODE>n</CODE>,
-if it has a numeric value,
-or
-the largest numerical index with a non-nil value in the table.
-<P>
-<A NAME="5.12"></A>
-<H2>5.12 - Calling Lua Functions</H2>
-<P>
-Functions defined in Lua
-(and C&nbsp;functions registered in Lua)
+</PRE>
+
+
+
+<p><code>lua_rawgeti</code> pushes the value of the <em>n</em>-th element of the table
+at stack position <code>index</code>.
+<code>lua_rawseti</code> sets the value of the <em>n</em>-th element of the table
+at stack position <code>index</code> to the value at the top of the stack,
+removing this value from the stack.
+
+<p><h2>3.14 - Calling Functions</h2>
+
+<p>Functions defined in Lua
+and C&nbsp;functions registered in Lua
 can be called from the host program.
 This is done using the following protocol:
 First, the function to be called is pushed onto the stack;
 then, the arguments to the function are pushed
-(see Section&nbsp;<A HREF="#pushing">5.5</A>) in <EM>direct order</EM>, that is, the first argument is pushed first.
+in <em>direct order</em>, that is, the first argument is pushed first.
 Finally, the function is called using
-<A NAME="lua_call"></A>
 <PRE>
-       int lua_call (lua_State *L, int nargs, int nresults);
+       void lua_call (lua_State *L, int nargs, int nresults);
 </PRE>
-This function returns the same error codes as <CODE>lua_dostring</CODE> and
-friends (see Section&nbsp;<A HREF="#luado">5.8</A>).
-If you want to propagate the error,
-instead of returning an error code,
-use
-<A NAME="lua_rawcall"></A>
-<PRE>
-       void lua_rawcall (lua_State *L, int nargs, int nresults);
-</PRE>
-<P>
-In both functions,
-<CODE>nargs</CODE> is the number of arguments that you pushed onto the stack.
+
+<code>nargs</code> is the number of arguments that you pushed onto the stack.
 All arguments and the function value are popped from the stack,
 and the function results are pushed.
-The number of results are adjusted (see Section&nbsp;<A HREF="#adjust">4.3</A>) to <CODE>nresults</CODE>,
-unless <CODE>nresults</CODE> is <A NAME="LUA_MULTRET"><TT>LUA_MULTRET</TT></A>.
-In that case, <EM>all</EM> results from the function are pushed.
-The function results are pushed in direct order
+The number of results are adjusted to <code>nresults</code>,
+unless <code>nresults</code> is <code>LUA_MULTRET</code>.
+In that case, <em>all</em> results from the function are pushed.
+Lua takes care that the returned values fit into the stack space.
+The function results are pushed onto the stack in direct order
 (the first result is pushed first),
 so that after the call the last result is on the top.
-<P>
-The following example shows how the host program may do the
-equivalent to the Lua code:
+
+<p>The following example shows how the host program may do the
+equivalent to this Lua code:
 <PRE>
-       a,b = f("how", t.x, 4)
+       a = f("how", t.x, 14)
 </PRE>
 Here it is in&nbsp;C:
 <PRE>
-    lua_getglobal(L, "t");                      /* global `t' (for later use) */
-    lua_getglobal(L, "f");                           /* function to be called */
+    lua_pushstring(L, "t");
+    lua_gettable(L, LUA_GLOBALSINDEX);          /* global `t' (for later use) */
+    lua_pushstring(L, "a");                                       /* var name */
+    lua_pushstring(L, "f");                                  /* function name */
+    lua_gettable(L, LUA_GLOBALSINDEX);               /* function to be called */
     lua_pushstring(L, "how");                                 /* 1st argument */
-    lua_pushstring(L, "x");                            /* push the string `x' */
-    lua_gettable(L, -4);                      /* push result of t.x (2nd arg) */
-    lua_pushnumber(L, 4);                                     /* 3rd argument */
-    lua_call(L, 3, 2);        /* call function with 3 arguments and 2 results */
-    lua_setglobal(L, "b");                         /* set global variable `b' */
-    lua_setglobal(L, "a");                         /* set global variable `a' */
+    lua_pushstring(L, "x");                            /* push the string "x" */
+    lua_gettable(L, -5);                      /* push result of t.x (2nd arg) */
+    lua_pushnumber(L, 14);                                    /* 3rd argument */
+    lua_call(L, 3, 1);         /* call function with 3 arguments and 1 result */
+    lua_settable(L, LUA_GLOBALSINDEX);             /* set global variable `a' */
     lua_pop(L, 1);                               /* remove `t' from the stack */
 </PRE>
-Notice that the code above is ``balanced'':
-at its end ,the stack is back to its original configuration.
+Note that the code above is "balanced":
+at its end, the stack is back to its original configuration.
 This is considered good programming practice.
-<P>
-<P>
-<P>
-Some special Lua functions have their own C&nbsp;interfaces.
-The host program can generate a Lua error calling the function
-<A NAME="lua_error"></A>
-<PRE>
-       void lua_error (lua_State *L, const char *message);
-</PRE>
-This function never returns.
-If <CODE>lua_error</CODE> is called from a C&nbsp;function that has been called from Lua,
-then the corresponding Lua execution terminates,
-as if an error had occurred inside Lua code.
-Otherwise, the whole host program terminates with a call to
-<CODE>exit(EXIT_FAILURE)</CODE>.
-Before terminating execution,
-the <CODE>message</CODE> is passed to the error handler function,
-<CODE>_ERRORMESSAGE</CODE> (see Section&nbsp;<A HREF="#error">4.7</A>).
-If <CODE>message</CODE> is <CODE>NULL</CODE>,
-then <CODE>_ERRORMESSAGE</CODE> is not called.
-<P>
-<P>
-Tag methods can be changed with <A NAME="lua_settagmethod"></A>
-<PRE>
-       void lua_settagmethod (lua_State *L, int tag, const char *event);
-</PRE>
-The second parameter is the tag,
-and the third is the event name (see Section&nbsp;<A HREF="#tag-method">4.8</A>);
-the new method is popped from the stack.
-To get the current value of a tag method,
-use the function <A NAME="lua_gettagmethod"></A>
-<PRE>
-       void lua_gettagmethod (lua_State *L, int tag, const char *event);
-</PRE>
-<P>
-It is also possible to copy all tag methods from one tag
-to another: <A NAME="lua_copytagmethods"></A>
-<PRE>
-       int lua_copytagmethods (lua_State *L, int tagto, int tagfrom);
-</PRE>
-This function returns <CODE>tagto</CODE>.
-<P>
-<P>
-You can traverse a table with the function <A NAME="lua_next"></A>
-<PRE>
-       int lua_next (lua_State *L, int index);
-</PRE>
-where <CODE>index</CODE> refers to the table to be traversed.
-The function pops a key from the stack,
-and pushes a key-value pair from the table
-(the ``next'' pair after the given key).
-If there are no more elements, then the function returns 0
-(and pushes nothing).
-A typical traversal looks like this:
-<PRE>
-       /* table is in the stack at index `t' */
-       lua_pushnil(L);  /* first key */
-       while (lua_next(L, t) != 0) {
-         /* `key' is at index -2 and `value' at index -1 */
-         printf("%s - %s\n",
-           lua_typename(L, lua_type(L, -2)), lua_typename(L, lua_type(L, -1)));
-         lua_pop(L, 1);  /* removes `value'; keeps `index' for next iteration */
-       }
-</PRE>
-<P>
-The function <A NAME="lua_concat"></A>
-<PRE>
-       void lua_concat (lua_State *L, int n);
-</PRE>
-concatenates the <CODE>n</CODE> values at the top of the stack,
-pops them, and leaves the result at the top;
-<CODE>n</CODE>&nbsp;must be at least 2.
-Concatenation is done following the usual semantics of Lua
-(see Section&nbsp;<A HREF="#concat">4.5.5</A>).
-<P>
-<P>
-<A NAME="LuacallC"></A>
-<A NAME="5.13"></A>
-<H2>5.13 - Defining C Functions</H2> 
-To register a C&nbsp;function to Lua,
-there is the following convenience macro:
-<A NAME="lua_register"></A>
-<PRE>
-     #define lua_register(L, n, f) (lua_pushcfunction(L, f), lua_setglobal(L, n))
-     /* const char *n;   */
-     /* lua_CFunction f; */
-</PRE>
-which receives the name the function will have in Lua,
-and a pointer to the function.
-This pointer must have type <CODE>lua_CFunction</CODE>,
+
+<p>(We did this example using only the raw functions provided by Lua's API,
+to show all the details.
+Usually programmers define and use several macros and auxiliary functions
+that provide higher level access to Lua.
+See the source code of the standard libraries for examples.)
+
+<p><a name="lua_pcall"><h2>3.15 - Protected Calls</h2></a>
+
+<p>When you call a function with <code>lua_call</code>,
+any error inside the called function is propagated upwards
+(with a <code>longjmp</code>).
+If you need to handle errors,
+then you should use <code>lua_pcall</code>:
+<PRE>
+       int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc);
+</PRE>
+Both <code>nargs</code> and <code>nresults</code> have the same meaning as
+in <code>lua_call</code>.
+If there are no errors during the call,
+<code>lua_pcall</code> behaves exactly like <code>lua_call</code>.
+However, if there is any error,
+<code>lua_pcall</code> catches it,
+pushes a single value at the stack (the error message),
+and returns an error code.
+Like <code>lua_call</code>,
+<code>lua_pcall</code> always removes the function
+and its arguments from the stack.
+
+<p>If <code>errfunc</code> is 0,
+then the error message returned is exactly the original error message.
+Otherwise, <code>errfunc</code> gives the stack index for an
+<em>error handler function</em>.
+(In the current implementation, that index cannot be a pseudo-index.)
+In case of runtime errors,
+that function will be called with the error message
+and its return value will be the message returned by <code>lua_pcall</code>.
+
+<p>Typically, the error handler function is used to add more debug
+information to the error message, such as a stack traceback.
+Such information cannot be gathered after the return of <code>lua_pcall</code>,
+since by then the stack has unwound.
+
+<p>The <code>lua_pcall</code> function returns 0 in case of success
+or one of the following error codes
+(defined in <code>lua.h</code>):
+<ul>
+<li> <code>LUA_ERRRUN</code> --- a runtime error.
+<li> <code>LUA_ERRMEM</code> --- memory allocation error.
+For such errors, Lua does not call the error handler function.
+<li> <code>LUA_ERRERR</code> ---
+error while running the error handler function.
+</ul>
+
+<p><a name="LuacallC"><h2>3.16 - Defining C Functions</h2></a>
+
+<p>Lua can be extended with functions written in&nbsp;C.
+These functions must be of type <code>lua_CFunction</code>,
 which is defined as
-<A NAME="lua_CFunction"></A>
 <PRE>
        typedef int (*lua_CFunction) (lua_State *L);
 </PRE>
-that is, a pointer to a function with integer result and a single argument,
-a Lua environment.
-<P>
-In order to communicate properly with Lua,
+
+A C&nbsp;function receives a Lua state and returns an integer,
+the number of values it wants to return to Lua.
+
+<p>In order to communicate properly with Lua,
 a C&nbsp;function must follow the following protocol,
 which defines the way parameters and results are passed:
-A C&nbsp;function receives its arguments from Lua in the stack,
+A C&nbsp;function receives its arguments from Lua in its stack
 in direct order (the first argument is pushed first).
+So, when the function starts,
+its first argument (if any) is at index 1.
 To return values to Lua, a C&nbsp;function just pushes them onto the stack,
 in direct order (the first result is pushed first),
 and returns the number of results.
+Any other value in the stack below the results will be properly
+discharged by Lua.
 Like a Lua function, a C&nbsp;function called by Lua can also return
 many results.
-<P>
-As an example, the following function receives a variable number
+
+<p>As an example, the following function receives a variable number
 of numerical arguments and returns their average and sum:
 <PRE>
        static int foo (lua_State *L) {
          int n = lua_gettop(L);    /* number of arguments */
-         double sum = 0;
+         lua_Number sum = 0;
          int i;
-         for (i = 1; i &lt;= n; i++) {
-           if (!lua_isnumber(L, i))
-             lua_error(L, "incorrect argument to function `average'");
+         for (i = 1; i &#060;= n; i++) {
+           if (!lua_isnumber(L, i)) {
+             lua_pushstring(L, "incorrect argument to function `average'");
+             lua_error(L);
+           }
            sum += lua_tonumber(L, i);
          }
          lua_pushnumber(L, sum/n);        /* first result */
@@ -2152,1648 +2457,2157 @@ of numerical arguments and returns their average and sum:
          return 2;                   /* number of results */
        }
 </PRE>
-This function may be registered in Lua as `<CODE>average</CODE>' by calling
+
+<p>To register a C&nbsp;function to Lua,
+there is the following convenience macro:
+<PRE>
+       #define lua_register(L,n,f) \
+               (lua_pushstring(L, n), \
+                lua_pushcfunction(L, f), \
+                lua_settable(L, LUA_GLOBALSINDEX))
+     /* lua_State *L;    */
+     /* const char *n;   */
+     /* lua_CFunction f; */
+</PRE>
+
+which receives the name the function will have in Lua
+and a pointer to the function.
+Thus,
+the C&nbsp;function <code>foo</code> above may be registered in Lua as
+<code>average</code> by calling
 <PRE>
        lua_register(L, "average", foo);
 </PRE>
-<P>
-<P>
-When a C&nbsp;function is created,
-it is possible to associate some <EM>upvalues</EM> to it
-(see Section&nbsp;<A HREF="#upvalue">4.6</A>),
-thus creating a <A NAME="C closure"><EM>C&nbsp;closure</EM></A>;
-these values are passed to the function whenever it is called,
-as ordinary arguments.
-To associate upvalues to a C&nbsp;function,
-first these values should be pushed onto the stack.
-Then the function <A NAME="lua_pushcclosure"></A>
+
+<p><a name="c-closure"><h2>3.17 - Defining C Closures</h2></a>
+
+<p>When a C&nbsp;function is created,
+it is possible to associate some values with it,
+thus creating a <em>C&nbsp;closure</em>;
+these values are then accessible to the function whenever it is called.
+To associate values with a C&nbsp;function,
+first these values should be pushed onto the stack
+(when there are multiple values, the first value is pushed first).
+Then the function
 <PRE>
        void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);
 </PRE>
+
 is used to push the C&nbsp;function onto the stack,
-with the argument <CODE>n</CODE> telling how many upvalues should be
+with the argument <code>n</code> telling how many values should be
 associated with the function
-(these upvalues are popped from the stack);
-in fact, the macro <CODE>lua_pushcfunction</CODE> is defined as
-<CODE>lua_pushcclosure</CODE> with <CODE>n</CODE> set to 0.
-Then, whenever the C&nbsp;function is called,
-these upvalues are inserted as the <EM>last</EM> arguments to the function,
-after the actual arguments provided in the call.
-This makes it easy to get the upvalues without knowing how many arguments
-the function received (recall that functions in Lua can receive any number of
-arguments): The <EM>i</EM>-th upvalue is in the stack at index <I>i-(n+1)</I>,
-where <EM>n</EM> is the number of upvalues.
-<P>
-For more examples of C&nbsp;functions and closures, see files
-<CODE>lbaselib.c</CODE>, <CODE>liolib.c</CODE>, <CODE>lmathlib.c</CODE>, and <CODE>lstrlib.c</CODE>
-in the official Lua distribution.
-<P>
-<A NAME="5.14"></A>
-<H2>5.14 - References to Lua Objects</H2>
-<P>
-If the C&nbsp;code needs to keep a Lua value
-outside the life span of a C&nbsp;function,
-then it must create a <A NAME="reference"><EM>reference</EM></A> to the value.
-The functions to manipulate references are the following:
-<A NAME="lua_ref"></A><A NAME="lua_getref"></A>
-<A NAME="lua_unref"></A>
-<PRE>
-       int   lua_ref    (lua_State *L, int lock);
-       int   lua_getref (lua_State *L, int ref);
-       void  lua_unref  (lua_State *L, int ref);
-</PRE>
-<P>
-<CODE>lua_ref</CODE> pops a value from
-the stack, creates a reference to it,
-and returns this reference.
-For a <B>nil</B> value,
-the reference is always <CODE>LUA_REFNIL</CODE>.<A NAME="LUA_REFNIL"></A>
-(<CODE>lua.h</CODE> also defines a constant <CODE>LUA_NOREF</CODE> <A NAME="LUA_NOREF"></A>
-that
-is different from any valid reference.)
-If <CODE>lock</CODE> is not zero, then the object is <EM>locked</EM>:
-this means the object will not be garbage collected.
-<EM>Unlocked references may be garbage collected</EM>.
-<P>
-Whenever the referenced object is needed in&nbsp;C,
-a call to <CODE>lua_getref</CODE>
-pushes that object onto the stack;
-if the object has been collected,
-<CODE>lua_getref</CODE> returns 0 (and does not push anything).
-<P>
-When a reference is no longer needed,
-it should be released with a call to <CODE>lua_unref</CODE>.
-<P>
-<P>
-<h3>Registry</h3>
-<P>
-When Lua starts, it registers a table at position
-<A NAME="LUA_REFREGISTRY"><TT>LUA_REFREGISTRY</TT></A>.
-It can be accessed through the macro<A NAME="lua_getregistry"></A>
-<PRE>
-  #define lua_getregistry(L)      lua_getref(L, LUA_REFREGISTRY)
-</PRE>
-This table can be used by C&nbsp;libraries as a general registry mechanism.
+(<code>lua_pushcclosure</code> also pops these values from the stack);
+in fact, the macro <code>lua_pushcfunction</code> is defined as
+<code>lua_pushcclosure</code> with <code>n</code> set to 0.
+
+<p>Then, whenever the C&nbsp;function is called,
+those values are located at specific pseudo-indices.
+Those pseudo-indices are produced by a macro <code>lua_upvalueindex</code>.
+The first value associated with a function is at position
+<code>lua_upvalueindex(1)</code>, and so on.
+Any access to <code>lua_upvalueindex(<em>n</em>)</code>,
+where <em>n</em> is greater than the number of upvalues of the
+current function,
+produces an acceptable (but invalid) index.
+
+<p>For examples of C&nbsp;functions and closures,
+see the standard libraries in the official Lua distribution
+(<code>src/lib/*.c</code>).
+
+<p><a name="registry"><h2>3.18 - Registry</h2></a>
+
+<p>Lua provides a registry,
+a pre-defined table that can be used by any C&nbsp;code to
+store whatever Lua value it needs to store,
+specially if the C&nbsp;code needs to keep that Lua value
+outside the life span of a C&nbsp;function.
+This table is always located at pseudo-index
+<code>LUA_REGISTRYINDEX</code>.
 Any C&nbsp;library can store data into this table,
-as long as it chooses a key different from other libraries.
-<P>
-<P>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="6."></A>
-<H1>6 - Standard Libraries</H1>
-<P>
-The standard libraries provide useful functions
-that are implemented directly through the standard API.
-Therefore, they are not necessary to the language,
+as long as it chooses keys different from other libraries.
+Typically, you should use as key a string containing your library name
+or a light userdata with the address of a C object in your code.
+
+<p>The integer keys in the registry are used by the reference mechanism,
+implemented by the auxiliary library,
+and therefore should not be used by other purposes.
+
+<p><h2>3.19 - Error Handling in C</h2>
+
+<p>Internally, Lua uses the C <code>longjmp</code> facility to handle errors.
+When Lua faces any error
+(such as memory allocation errors, type errors, syntax errors)
+it <em>raises</em> an error, that is, it does a long jump.
+A <em>protected environment</em> uses <code>setjmp</code>
+to set a recover point,
+and any error jumps to the most recent active recover point.
+
+<p>If an error happens outside any protected environment,
+Lua calls a <em>panic function</em>,
+and then calls <code>exit(EXIT_FAILURE)</code>.
+You can change the panic function with
+<PRE>
+       lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);
+</PRE>
+Your new panic function may avoid the application exit by
+never returning (e.g. doing a long jump).
+Nevertheless, the corresponding Lua will not be consistent;
+the only safe operation with it is to close it.
+
+<p>Almost any function in the API may raise an error,
+for instance due to a memory allocation error.
+The following functions run in protected mode
+(that is, they create a protected environment to run),
+so they never raise an error:
+<code>lua_open</code>, <code>lua_close</code>, <code>lua_load</code>,
+and <code>lua_pcall</code>.
+
+<p>There is yet another function that runs a given C function in protected mode:
+<PRE>
+       int lua_cpcall (lua_State *L, lua_CFunction func, void *ud);
+</PRE>
+
+<code>lua_cpcall</code> calls <code>func</code> in protected mode.
+<code>func</code> starts with only one element in its stack,
+a light userdata containing <code>ud</code>.
+In case of errors,
+<code>lua_cpcall</code> returns the same error codes as <code>lua_pcall</code>
+(see <a href="#lua_pcall">3.15</a>),
+plus the error object on the top of the stack;
+otherwise, it returns zero, and does not change the stack.
+Any value returned by <code>func</code> is dicarded.
+
+<p>C code can generate a Lua error calling the function
+<PRE>
+       void lua_error (lua_State *L);
+</PRE>
+
+The error message (which actually can be any type of object)
+must be on the stack top.
+This function does a long jump,
+and therefore never returns.
+
+<p><h2>3.20 - Threads</h2>
+
+<p>Lua offers partial support for multiple threads of execution.
+If you have a C&nbsp;library that offers multi-threading, 
+then Lua can cooperate with it to implement the equivalent facility in Lua.
+Also, Lua implements its own coroutine system on top of threads.
+The following function creates a new thread in Lua:
+<PRE>
+       lua_State *lua_newthread (lua_State *L);
+</PRE>
+
+This function pushes the thread on the stack and returns a pointer to
+a <code>lua_State</code> that represents this new thread.
+The new state returned by this function shares with the original state
+all global objects (such as tables),
+but has an independent run-time stack.
+
+<p>Each thread has an independent global environment table.
+When you create a thread, this table is the same as that of the given state,
+but you can change each one independently.
+
+<p>You destroy threads with <code>lua_closethread</code>:
+<PRE>
+       void lua_closethread (lua_State *L, lua_State *thread);
+</PRE>
+You cannot close the sole (or last) thread of a state.
+Instead, you must close the state itself.
+
+<p>To manipulate threads as coroutines,
+Lua offers the following functions:
+<PRE>
+       int lua_resume (lua_State *L, int narg);
+       int lua_yield (lua_State *L, int nresults);
+</PRE>
+
+To start a coroutine, you first create a new thread;
+then you push on its stack the body function plus any eventual arguments;
+then you call <code>lua_resume</code>,
+with <code>narg</code> being the number of arguments.
+This call returns when the coroutine suspends or finishes its execution.
+When it returns, the stack contains all values passed to <code>lua_yield</code>,
+or all values returned by the body function.
+<code>lua_resume</code> returns 0 if there is no errors running the coroutine,
+or an error code (see <a href="#lua_pcall">3.15</a>).
+In case of errors,
+the stack contains only the error message.
+To restart a coroutine, you put on its stack only the values to
+be passed as results from <code>yield</code>,
+and then call <code>lua_resume</code>.
+
+<p>The <code>lua_yield</code> function can only be called as the
+return expression of a C function, as follows:
+<PRE>
+       return lua_yield (L, nresults);
+</PRE>
+When a C function calls <code>lua_yield</code> in that way,
+the running coroutine suspends its execution,
+and the call to <code>lua_resume</code> that started this coroutine returns.
+The parameter <code>nresults</code> is the number of values from the stack
+that are passed as results to <code>lua_resume</code>.
+
+<p>To exchange values between different threads,
+you may use <code>lua_xmove</code>:
+<PRE>
+       void lua_xmove (lua_State *from, lua_State *to, int n);
+</PRE>
+It pops <code>n</code> values from the stack <code>from</code>,
+and puhses them into the stack <code>to</code>.
+
+<p>
+<a name="debugI"><h1>4 - The Debug Interface</h1></a>
+
+<p>Lua has no built-in debugging facilities.
+Instead, it offers a special interface
+by means of functions and <em>hooks</em>.
+This interface allows the construction of different
+kinds of debuggers, profilers, and other tools
+that need "inside information" from the interpreter.
+
+<p><h2>4.1 - Stack and Function Information</h2>
+
+<p>The main function to get information about the interpreter runtime stack is
+<PRE>
+       int lua_getstack (lua_State *L, int level, lua_Debug *ar);
+</PRE>
+
+This function fills parts of a <code>lua_Debug</code> structure with
+an identification of the <em>activation record</em>
+of the function executing at a given level.
+Level&nbsp;0 is the current running function,
+whereas level <em>n+1</em> is the function that has called level <em>n</em>.
+When there is no errors, <code>lua_getstack</code> returns 1;
+when called with a level greater than the stack depth,
+it returns 0.
+
+<p>The structure <code>lua_Debug</code> is used to carry different pieces of
+information about an active function:
+<PRE>
+      typedef struct lua_Debug {
+        int event;
+        const char *name;      /* (n) */
+        const char *namewhat;  /* (n) `global', `local', `field', `method' */
+        const char *what;      /* (S) `Lua' function, `C' function, Lua `main' */
+        const char *source;    /* (S) */
+        int currentline;       /* (l) */
+        int nups;              /* (u) number of upvalues */
+        int linedefined;       /* (S) */
+        char short_src[LUA_IDSIZE]; /* (S) */
+
+        /* private part */
+        ...
+      } lua_Debug;
+</PRE>
+
+<code>lua_getstack</code> fills only the private part
+of this structure, for later use.
+To fill the other fields of <code>lua_Debug</code> with useful information,
+call
+<PRE>
+       int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
+</PRE>
+
+This function returns 0 on error
+(for instance, an invalid option in <code>what</code>).
+Each character in the string <code>what</code>
+selects some fields of the structure <code>ar</code> to be filled,
+as indicated by the letter in parentheses in the definition of <code>lua_Debug</code>
+above:
+`<code>S</code>&acute; fills in the fields <code>source</code>, <code>linedefined</code>,
+and <code>what</code>;
+`<code>l</code>&acute; fills in the field <code>currentline</code>, etc.
+Moreover, `<code>f</code>&acute; pushes onto the stack the function that is
+running at the given level.
+
+<p>To get information about a function that is not active
+(that is, not in the stack),
+you push it onto the stack
+and start the <code>what</code> string with the character `<code>></code>&acute;.
+For instance, to know in which line a function <code>f</code> was defined,
+you can write
+<PRE>
+       lua_Debug ar;
+       lua_pushstring(L, "f");
+       lua_gettable(L, LUA_GLOBALSINDEX);  /* get global `f' */
+       lua_getinfo(L, ">S", &#038;ar);
+       printf("%d\n", ar.linedefined);
+</PRE>
+The fields of <code>lua_Debug</code> have the following meaning:
+<ul>
+
+<p><li><b><code>source</code></b>
+If the function was defined in a string,
+then <code>source</code> is that string.
+If the function was defined in a file,
+then <code>source</code> starts with a `<code>@</code>&acute; followed by the file name.
+
+<p><li><b><code>short_src</code></b>
+A "printable" version of <code>source</code>, to be used in error messages.
+
+<p><li><b><code>linedefined</code></b>
+the line number where the definition of the function starts.
+
+<p><li><b><code>what</code></b> the string <code>"Lua"</code> if this is a Lua function,
+<code>"C"</code> if this is a C&nbsp;function,
+<code>"main"</code> if this is the main part of a chunk,
+and <code>"tail"</code> if this was a function that did a tail call.
+In the latter case,
+Lua has no other information about this function.
+
+<p><li><b><code>currentline</code></b>
+the current line where the given function is executing.
+When no line information is available,
+<code>currentline</code> is set to <em>-1</em>.
+
+<p><li><b><code>name</code></b>
+a reasonable name for the given function.
+Because functions in Lua are first class values,
+they do not have a fixed name:
+Some functions may be the value of multiple global variables,
+while others may be stored only in a table field.
+The <code>lua_getinfo</code> function checks how the function was
+called or whether it is the value of a global variable to
+find a suitable name.
+If it cannot find a name,
+then <code>name</code> is set to <code>NULL</code>.
+
+<p><li><b><code>namewhat</code></b>
+Explains the <code>name</code> field.
+The value of <code>namewhat</code> can be
+<code>"global"</code>, <code>"local"</code>, <code>"method"</code>,
+<code>"field"</code>, or <code>""</code> (the empty string),
+according to how the function was called.
+(Lua uses the empty string when no other option seems to apply.)
+
+<p><li><b><code>nups</code></b>
+The number of upvalues of the function.
+
+<p></ul>
+
+<p><h2>4.2 - Manipulating Local Variables and Upvalues</h2>
+
+<p>For the manipulation of local variables and upvalues,
+the debug interface uses indices:
+The first parameter or local variable has index&nbsp;1, and so on,
+until the last active local variable.
+Upvalues have no particular order,
+as they are active through the whole function.
+
+<p>The following functions allow the manipulation of the
+local variables of a given activation record:
+<PRE>
+       const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);
+       const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);
+</PRE>
+
+The parameter <code>ar</code> must be a valid activation record that was
+filled by a previous call to <code>lua_getstack</code> or
+given as argument to a hook (see <a href="#sub-hooks">4.3</a>).
+<code>lua_getlocal</code> gets the index <code>n</code> of a local variable,
+pushes the variable's value onto the stack,
+and returns its name.
+<code>lua_setlocal</code> assigns the value at the top of the stack
+to the variable and returns its name.
+Both functions return <code>NULL</code>
+when the index is greater than
+the number of active local variables.
+
+<p>The following functions allow the manipulation of the
+upvalues of a given function
+(unlike local variables,
+the upvalues of a function are accessible even when the
+function is not active):
+<PRE>
+       const char *lua_getupvalue (lua_State *L, int funcindex, int n);
+       const char *lua_setupvalue (lua_State *L, int funcindex, int n);
+</PRE>
+
+These functions operate both on Lua functions and on C&nbsp;functions.
+(For Lua functions,
+upvalues are the external local variables that the function uses,
+and that consequently are included in its closure.)
+<code>funcindex</code> points to a function in the stack.
+<code>lua_getpuvalue</code> gets the index <code>n</code> of an upvalue,
+pushes the upvalue's value onto the stack,
+and returns its name.
+<code>lua_setupvalue</code> assigns the value at the top of the stack
+to the upvalue and returns its name.
+Both functions return <code>NULL</code>
+when the index is greater than the number of upvalues.
+For C&nbsp;functions, these functions use the empty string <code>""</code>
+as a name for all upvalues.
+
+<p>As an example, the following function lists the names of all
+local variables and upvalues for a function at a given level of the stack:
+<PRE>
+       int listvars (lua_State *L, int level) {
+         lua_Debug ar;
+         int i;
+         const char *name;
+         if (lua_getstack(L, level, &#038;ar) == 0)
+           return 0;  /* failure: no such level in the stack */
+         i = 1;
+         while ((name = lua_getlocal(L, &#038;ar, i++)) != NULL) {
+           printf("local %d %s\n", i-1, name);
+           lua_pop(L, 1);  /* remove variable value */
+         }
+         lua_getinfo(L, "f", &#038;ar);  /* retrieves function */
+         i = 1;
+         while ((name = lua_getpuvalue(L, -1, i++)) != NULL) {
+           printf("upvalue %d %s\n", i-1, name);
+           lua_pop(L, 1);  /* remove upvalue value */
+         }
+         return 1;
+       }
+</PRE>
+
+<p><a name="sub-hooks"><h2>4.3 - Hooks</h2></a>
+
+<p>Lua offers a mechanism of hooks, which are
+user-defined C functions that are called during the program execution.
+A hook may be called in four different events:
+a <em>call</em> event, when Lua calls a function;
+a <em>return</em> event, when Lua returns from a function;
+a <em>line</em> event, when Lua starts executing a new line of code;
+and a <em>count</em> event, which happens every "count" instructions.
+Lua identifies these events with the following constants:
+<code>LUA_HOOKCALL</code>,
+<code>LUA_HOOKRET</code> (or <code>LUA_HOOKTAILRET</code>, see below),
+<code>LUA_HOOKLINE</code>,
+and <code>LUA_HOOKCOUNT</code>.
+
+<p>A hook has type <code>lua_Hook</code>, defined as follows:
+<PRE>
+       typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
+</PRE>
+
+You can set the hook with the following function:
+<PRE>
+       int lua_sethook (lua_State *L, lua_Hook func, int mask, int count);
+</PRE>
+
+<code>func</code> is the hook.
+<code>mask</code> specifies on which events the hook will be called:
+It is formed by a disjunction of the constants
+<code>LUA_MASKCALL</code>,
+<code>LUA_MASKRET</code>,
+<code>LUA_MASKLINE</code>,
+and <code>LUA_MASKCOUNT</code>.
+The <code>count</code> argument is only meaningful when the mask
+includes <code>LUA_MASKCOUNT</code>.
+For each event, the hook is called as explained below:
+<ul>
+<li><b>The call hook</b> is called when the interpreter calls a function.
+The hook is called just after Lua enters the new function.
+<li><b>The return hook</b> is called when the interpreter returns from a function.
+The hook is called just before Lua leaves the function.
+<li><b>The line hook</b> is called when the interpreter is about to
+start the execution of a new line of code,
+or when it jumps back in the code (even to the same line).
+(This event only happens while Lua is executing a Lua function.)
+<li><b>The count hook</b> is called after the interpreter executes every
+<code>count</code> instructions.
+(This event only happens while Lua is executing a Lua function.)
+</ul>
+
+<p>A hook is disabled by setting <code>mask</code> to zero.
+
+<p>You can get the current hook, the current mask,
+and the current count with the next functions:
+<PRE>
+       lua_Hook lua_gethook      (lua_State *L);
+       int      lua_gethookmask  (lua_State *L);
+       int      lua_gethookcount (lua_State *L);
+</PRE>
+
+
+<p>Whenever a hook is called, its <code>ar</code> argument has its field
+<code>event</code> set to the specific event that triggered the hook.
+Moreover, for line events, the field <code>currentline</code> is also set.
+To get the value of any other field in <code>ar</code>,
+the hook must call <code>lua_getinfo</code>.
+For return events, <code>event</code> may be <code>LUA_HOOKRET</code>,
+the normal value, or <code>LUA_HOOKTAILRET</code>.
+In the latter case, Lua is simulating a return from
+a function that did a tail call;
+in this case, it is useless to call <code>lua_getinfo</code>.
+
+<p>While Lua is running a hook, it disables other calls to hooks.
+Therefore, if a hook calls back Lua to execute a function or a chunk,
+that execution occurs without any calls to hooks.
+
+<p>
+<a name="libraries"><h1>5 - Standard Libraries</h1></a>
+
+<p>The standard libraries provide useful functions
+that are implemented directly through the C API.
+Some of these functions provide essential services to the language
+(e.g., <code>type</code> and <code>getmetatable</code>);
+others provide access to "outside" services (e.g., I/O);
+and others could be implemented in Lua itself,
+but are quite useful or have critical performance to
+deserve an implementation in C (e.g., <code>sort</code>).
+
+<p>All libraries are implemented through the official C API
 and are provided as separate C&nbsp;modules.
 Currently, Lua has the following standard libraries:
-<UL>
-<LI>basic library;
-<LI>string manipulation;
-<LI>mathematical functions (sin, log, etc);
-<LI>input and output (plus some system facilities).
-</UL>
-To have access to these libraries,
-the C&nbsp;host program must call the functions
-<CODE>lua_baselibopen</CODE>,
-<CODE>lua_strlibopen</CODE>, <CODE>lua_mathlibopen</CODE>,
-and <CODE>lua_iolibopen</CODE>, which are declared in <CODE>lualib.h</CODE>.
-<A NAME="lua_baselibopen"></A>
-<A NAME="lua_strlibopen"></A>
-<A NAME="lua_mathlibopen"></A>
-<A NAME="lua_iolibopen"></A>
-<P>
-<A NAME="predefined"></A>
-<A NAME="6.1"></A>
-<H2>6.1 - Basic Functions</H2> 
-<P>
-The basic library provides some core functions to Lua.
-Therefore, if you do not include this library in your application,
+<ul>
+<li> basic library;
+<li> string manipulation;
+<li> table manipulation;
+<li> mathematical functions (sin, log, etc.);
+<li> input and output;
+<li> operating system facilities;
+<li> debug facilities.
+</ul>
+Except for the basic library,
+each library provides all its functions as fields of a global table
+or as methods of its objects.
+
+<p>To have access to these libraries,
+the C&nbsp;host program must first call the functions
+<code>luaopen_base</code> (for the basic library),
+<code>luaopen_string</code> (for the string library),
+<code>luaopen_table</code> (for the table library),
+<code>luaopen_math</code> (for the mathematical library),
+<code>luaopen_io</code> (for the I/O and the Operating System libraries),
+and <code>luaopen_debug</code> (for the debug library).
+These functions are declared in <code>lualib.h</code>.
+
+
+
+
+
+
+
+<p><a name="predefined"><h2>5.1 - Basic Functions</h2></a>
+
+<p>The basic library provides some core functions to Lua.
+If you do not include this library in your application,
 you should check carefully whether you need to provide some alternative
-implementation for some facilities.
-(For instance,
-without function <CODE>_ERRORMESSAGE</CODE>,
-Lua is unable to show error messages.)
-<P>
-<A NAME="alert"></A>
-<h3> <TT>_ALERT (message)</TT></h3><A NAME="alert"></A>
-Prints its only string argument to <A NAME="stderr"><TT>stderr</TT></A>.
-All error messages in Lua are printed through the function stored
-in the <CODE>_ALERT</CODE> global variable
-(see Section&nbsp;<A HREF="#error">4.7</A>).
-Therefore, a program may assign another function to this variable
-to change the way such messages are shown
-(for instance, for systems without <CODE>stderr</CODE>).
-<P>
-<h3> <TT>assert (v [, message])</TT></h3><A NAME="assert"></A>
-Issues an <EM>``assertion failed!''</EM> error
-when its argument <CODE>v</CODE> is <B>nil</B>.
-This function is equivalent to the following Lua function:
-<PRE>
-       function assert (v, m)
-         if not v then
-           m = m or ""
-           error("assertion failed!  " .. m)
-         end
-       end
-</PRE>
-<P>
-<h3> <TT>call (func, arg [, mode [, errhandler]])</TT></h3><A NAME="call"></A>
-<A NAME="pdf-call"></A>
-
-Calls function <CODE>func</CODE> with
-the arguments given by the table <CODE>arg</CODE>.
-The call is equivalent to
-<PRE>
-       func(arg[1], arg[2], ..., arg[n])
-</PRE>
-where <CODE>n</CODE> is the result of <CODE>getn(arg)</CODE> (see Section&nbsp;<A HREF="#getn">6.1</A>).
-All results from <CODE>func</CODE> are simply returned by <CODE>call</CODE>.
-<P>
-By default,
-if an error occurs during the call to <CODE>func</CODE>,
-the error is propagated.
-If the string <CODE>mode</CODE> contains <CODE>"x"</CODE>,
-then the call is <EM>protected</EM>.<A NAME="protected calls"></A>
-In this mode, function <CODE>call</CODE> does not propagate an error,
-regardless of what happens during the call.
-Instead, it returns <B>nil</B> to signal the error
-(besides calling the appropriated error handler).
-<P>
-If <CODE>errhandler</CODE> is provided,
-the error function <CODE>_ERRORMESSAGE</CODE> is temporarily set to <CODE>errhandler</CODE>,
-while <CODE>func</CODE> runs.
-In particular, if <CODE>errhandler</CODE> is <B>nil</B>,
-no error messages will be issued during the execution of the called function.
-<P>
-<h3> <TT>collectgarbage ([limit])</TT></h3><A NAME="collectgarbage"></A>
-<P>
-Sets the garbage-collection threshold for the given limit
-(in Kbytes), and checks it against the byte counter.
+implementation for some of its facilities.
+
+<p><h3><code>assert (v [, message])</code></h3>
+Issues an  error when
+the value of its argument <code>v</code> is <B>nil</B> or <B>false</B>;
+otherwise, returns this value.
+<code>message</code> is an error message;
+when absent, it defaults to "assertion failed!"
+
+<p><h3><code>collectgarbage ([limit])</code></h3>
+
+<p>Sets the garbage-collection threshold to the given limit
+(in Kbytes) and checks it against the byte counter.
 If the new threshold is smaller than the byte counter,
-then Lua immediately runs the garbage collector (see Section&nbsp;<A HREF="#GC">5.6</A>).
-If <CODE>limit</CODE> is absent, it defaults to zero
+then Lua immediately runs the garbage collector (see <a href="#GC">2.9</a>).
+If <code>limit</code> is absent, it defaults to zero
 (thus forcing a garbage-collection cycle).
-<P>
-<h3> <TT>copytagmethods (tagto, tagfrom)</TT></h3>
-<A NAME="copytagmethods"></A>
-Copies all tag methods from one tag to another;
-returns <CODE>tagto</CODE>.
-<P>
-<h3> <TT>dofile (filename)</TT></h3><A NAME="dofile"></A>
-Receives a file name,
-opens the named file, and executes its contents as a Lua chunk,
-or as pre-compiled chunks.
+
+<p><h3><code>dofile (filename)</code></h3>
+Opens the named file and executes its contents as a Lua chunk.
 When called without arguments,
-<CODE>dofile</CODE> executes the contents of the standard input (<CODE>stdin</CODE>).
-If there is any error executing the file,
-then <CODE>dofile</CODE> returns <B>nil</B>.
-Otherwise, it returns the values returned by the chunk,
-or a non-<B>nil</B> value if the chunk returns no values.
-It issues an error when called with a non-string argument.
-<P>
-<h3> <TT>dostring (string [, chunkname])</TT></h3><A NAME="dostring"></A>
-Executes a given string as a Lua chunk.
-If there is any error executing the string,
-then <CODE>dostring</CODE> returns <B>nil</B>.
-Otherwise, it returns the values returned by the chunk,
-or a non-<B>nil</B> value if the chunk returns no values.
-The optional parameter <CODE>chunkname</CODE>
-is the ``name of the chunk'',
-used in error messages and debug information.
-<P>
-<A NAME="pdf-error"></A>
-<h3> <TT>error (message)</TT></h3><A NAME="error"></A>
-Calls the error handler (see Section&nbsp;<A HREF="#error">4.7</A>) and then terminates
-the last protected function called
-(in&nbsp;C: <CODE>lua_dofile</CODE>, <CODE>lua_dostring</CODE>,
-<CODE>lua_dobuffer</CODE>, or <CODE>lua_callfunction</CODE>;
-in Lua: <CODE>dofile</CODE>, <CODE>dostring</CODE>, or <CODE>call</CODE> in protected mode).
-If <CODE>message</CODE> is <B>nil</B>, then the error handler is not called.
-Function <CODE>error</CODE> never returns.
-<P>
-<h3> <TT>foreach (table, func)</TT></h3><A NAME="foreach"></A>
-Executes the given <CODE>func</CODE> over all elements of <CODE>table</CODE>.
-For each element, the function is called with the index and
-respective value as arguments.
-If the function returns any non-<B>nil</B> value,
-then the loop is broken, and this value is returned
-as the final value of <CODE>foreach</CODE>.
-This function could be defined in Lua:
+<code>dofile</code> executes the contents of the standard input (<code>stdin</code>).
+Returns any value returned by the chunk.
+In case of errors, <code>dofile</code> propagates the error
+to its caller (that is, it does not run in protected mode).
+
+<p><a name="pdf-error"><h3><code>error (message [, level])</code></h3></a>
+
+Terminates the last protected function called,
+and returns <code>message</code> as the error message.
+Function <code>error</code> never returns.
+
+<p>The <code>level</code> argument specifies where the error
+message points the error.
+With level 1 (the default), the error position is where the
+<code>error</code> function was called.
+Level 2 points the error to where the function
+that called <code>error</code> was called; and so on.
+
+<p><h3><code>_G</code></h3>
+A global variable (not a function) that
+holds the global environment (that is, <code>_G._G = _G</code>).
+Lua itself does not use this variable;
+changing its value does not affect any environment.
+(Use <code>setfenv</code> to change environments.)
+
+<p><h3><code>getfenv (f)</code></h3>
+Returns the current environment in use by the function.
+<code>f</code> can be a Lua function or a number,
+which specifies the function at that stack level:
+Level 1 is the function calling <code>getfenv</code>.
+If the given function is not a Lua function,
+or if <code>f</code> is 0,
+<code>getfenv</code> returns the global environment.
+The default for <code>f</code> is 1.
+
+<p>if the environment has a <code>"__fenv"</code> field,
+returns the associated value, instead of the environment.
+
+<p><a name="pdf-getmetatable"><h3><code>getmetatable (object)</code></h3></a>
+
+
+<p>If the object does not have a metatable, returns <B>nil</B>.
+Otherwise,
+if the object's metatable has a <code>"__metatable"</code> field,
+returns the associated value.
+Otherwise, returns the metatable of the given object.
+
+<p><h3><code>gcinfo ()</code></h3>
+
+<p>Returns two results:
+the number of Kbytes of dynamic memory that Lua is using
+and the current garbage collector threshold (also in Kbytes).
+
+<p><h3><code>ipairs (t)</code></h3>
+
+<p>Returns an iterator function, the table <code>t</code>, and 0,
+so that the construction
 <PRE>
-       function foreach (t, f)
-         for i, v in t do
-           local res = f(i, v)
-           if res then return res end
-         end
-       end
+       for i,v in ipairs(t) do ... end
 </PRE>
-<P>
-The behavior of <CODE>foreach</CODE> is <EM>undefined</EM> if you change
-the table <CODE>t</CODE> during the traversal.
-<P>
-<P>
-<h3> <TT>foreachi (table, func)</TT></h3><A NAME="foreachi"></A>
-Executes the given <CODE>func</CODE> over the
-numerical indices of <CODE>table</CODE>.
-For each index, the function is called with the index and
-respective value as arguments.
-Indices are visited in sequential order,
-from&nbsp;1 to <CODE>n</CODE>,
-where <CODE>n</CODE> is the result of <CODE>getn(table)</CODE> (see Section&nbsp;<A HREF="#getn">6.1</A>).
-If the function returns any non-<B>nil</B> value,
-then the loop is broken, and this value is returned
-as the final value of <CODE>foreachi</CODE>.
-This function could be defined in Lua:
+will iterate over the pairs (<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
+up to the first integer key with a nil value in the table.
+
+<p><h3><code>loadfile (filename)</code></h3>
+
+<p>Loads a file as a Lua chunk (without running it).
+If there are no errors, 
+returns the compiled chunk as a function;
+otherwise, returns <B>nil</B> plus the error message.
+The environment of the returned function is the global environment.
+
+<p><h3><code>loadlib (libname, funcname)</code></h3>
+
+<p>Links the program with the dynamic C library <code>libname</code>.
+Inside this library, looks for a function <code>funcname</code>
+and returns this function as a C function.
+
+<p><code>libname</code> must be the complete file name of the C library,
+including any eventual path and extension.
+
+<p>This function is not supported by ANSI C.
+As such, it is only available on some platforms
+(Windows, Linux, Solaris, BSD, plus other Unix systems that
+support the <code>dlfcn</code> standard).
+
+<p><h3><code>loadstring (string [, chunkname])</code></h3>
+Loads a string as a Lua chunk (without running it).
+If there are no errors, 
+returns the compiled chunk as a function;
+otherwise, returns <B>nil</B> plus the error message.
+The environment of the returned function is the global environment.
+
+<p>The optional parameter <code>chunkname</code>
+is the name to be used in error messages and debug information.
+
+<p>To load and run a given string, use the idiom
 <PRE>
-       function foreachi (t, f)
-         for i=1,getn(t) do
-           local res = f(i, t[i])
-           if res then return res end
-         end
-       end
-</PRE>
-<P>
-<P>
-<h3> <TT>getglobal (name)</TT></h3><A NAME="getglobal"></A>
-Gets the value of a global variable,
-or calls a tag method for ``getglobal''.
-Its full semantics is explained in Section&nbsp;<A HREF="#tag-method">4.8</A>.
-The string <CODE>name</CODE> does not need to be a
-syntactically valid variable name.
-<P>
-<A NAME="getn"></A>
-<h3> <TT>getn (table)</TT></h3><A NAME="getn"></A>
-Returns the ``size'' of a table, when seen as a list.
-If the table has an <CODE>n</CODE> field with a numeric value,
-this value is the ``size'' of the table.
-Otherwise, the ``size'' is the largest numerical index with a non-nil
-value in the table.
-This function could be defined in Lua:
-<PRE>
-       function getn (t)
-         if type(t.n) == "number" then return t.n end
-         local max = 0
-         for i, _ in t do
-           if type(i) == "number" and i&gt;max then max=i end
-         end
-         return max
-       end
+      assert(loadstring(s))()
 </PRE>
-<P>
-<h3> <TT>gettagmethod (tag, event)</TT></h3>
-<A NAME="gettagmethod"></A>
-Returns the current tag method
-for a given pair <EM>(tag, event)</EM>.
-This function cannot be used to get a tag method for the ``gc'' event.
-(Such tag methods can only be manipulated by C&nbsp;code.)
-<P>
-<h3> <TT>globals ([table])</TT></h3><A NAME="globals"></A>
-Returns the current table of globals.
-If the argument <CODE>table</CODE> is given,
-then it also sets this table as the table of globals.
-<P>
-<A NAME="pdf-newtag"></A>
-<h3> <TT>newtag ()</TT></h3><A NAME="newtag"></A>
-Returns a new tag.
-<P>
-<h3> <TT>next (table, [index])</TT></h3><A NAME="next"></A>
+
+<p><h3><code>next (table [, index])</code></h3>
 Allows a program to traverse all fields of a table.
 Its first argument is a table and its second argument
 is an index in this table.
-<CODE>next</CODE> returns the next index of the table and the
+<code>next</code> returns the next index of the table and the
 value associated with the index.
 When called with <B>nil</B> as its second argument,
-<CODE>next</CODE> returns the first index
+<code>next</code> returns the first index
 of the table and its associated value.
 When called with the last index,
 or with <B>nil</B> in an empty table,
-<CODE>next</CODE> returns <B>nil</B>.
+<code>next</code> returns <B>nil</B>.
 If the second argument is absent, then it is interpreted as <B>nil</B>.
-<P>
-Lua has no declaration of fields;
-semantically, there is no difference between a
+
+<p>Lua has no declaration of fields;
+There is no difference between a
 field not present in a table or a field with value <B>nil</B>.
-Therefore, <CODE>next</CODE> only considers fields with non-<B>nil</B> values.
+Therefore, <code>next</code> only considers fields with non-<B>nil</B> values.
 The order in which the indices are enumerated is not specified,
-<EM>even for numeric indices</EM>
-(to traverse a table in numeric order,
-use a numerical <B>for</B> or the function <CODE>foreachi</CODE>).
-<P>
-The behavior of <CODE>next</CODE> is <EM>undefined</EM> if you change
-the table during the traversal.
-<P>
-<h3> <TT>print (e1, e2, ...)</TT></h3><A NAME="print"></A>
+<em>even for numeric indices</em>.
+(To traverse a table in numeric order,
+use a numerical <b>for</b> or the <code>ipairs</code> function.)
+
+<p>The behavior of <code>next</code> is <em>undefined</em> if,
+during the traversal,
+you assign any value to a non-existent field in the table.
+
+<p><h3><code>pairs (t)</code></h3>
+
+<p>Returns the <code>next</code> function and the table <code>t</code> (plus a <B>nil</B>),
+so that the construction
+<PRE>
+       for k,v in pairs(t) do ... end
+</PRE>
+will iterate over all key-value pairs of table <code>t</code>.
+
+<p><a name="pdf-pcall"><h3><code>pcall (f, arg1, arg2, ...)</code></h3></a>
+
+<p>Calls function <code>f</code> with
+the given arguments in protected mode.
+That means that any error inside <code>f</code> is not propagated;
+instead, <code>pcall</code> catches the error
+and returns a status code.
+Its first result is the status code (a boolean),
+which is true if the call succeeds without errors.
+In such case, <code>pcall</code> also returns all results from the call,
+after this first result.
+In case of any error, <code>pcall</code> returns <B>false</B> plus the error message.
+
+<p><h3><code>print (e1, e2, ...)</code></h3>
 Receives any number of arguments,
-and prints their values using the strings returned by <CODE>tostring</CODE>.
+and prints their values in <code>stdout</code>,
+using the <code>tostring</code> function to convert them to strings.
 This function is not intended for formatted output,
 but only as a quick way to show a value,
-for instance for debugging.
-See Section&nbsp;<A HREF="#libio">6.4</A> for functions for formatted output.
-<P>
-<h3> <TT>rawget (table, index)</TT></h3><A NAME="rawget"></A>
-Gets the real value of <CODE>table[index]</CODE>,
-without invoking any tag method.
-<CODE>table</CODE> must be a table,
-and <CODE>index</CODE> is any value different from <B>nil</B>.
-<P>
-<h3> <TT>rawset (table, index, value)</TT></h3><A NAME="rawset"></A>
-Sets the real value of <CODE>table[index]</CODE> to <CODE>value</CODE>,
-without invoking any tag method.
-<CODE>table</CODE> must be a table,
-<CODE>index</CODE> is any value different from <B>nil</B>,
-and <CODE>value</CODE> is any Lua value.
-<P>
-<h3> <TT>setglobal (name, value)</TT></h3><A NAME="setglobal"></A>
-Sets the named global variable to the given value,
-or calls a tag method for ``setglobal''.
-Its full semantics is explained in Section&nbsp;<A HREF="#tag-method">4.8</A>.
-The string <CODE>name</CODE> does not need to be a
-syntactically valid variable name.
-<P>
-<h3> <TT>settag (t, tag)</TT></h3><A NAME="settag"></A>
-Sets the tag of a given table (see Section&nbsp;<A HREF="#TypesSec">3</A>).
-<CODE>tag</CODE> must be a value created with <CODE>newtag</CODE>
-(see Section&nbsp;<A HREF="#pdf-newtag">6.1</A>).
-<CODE>settag</CODE> returns the value of its first argument (the table).
-For the safety of host programs,
-it is impossible to change the tag of a userdata from Lua.
-<P>
-<h3> <TT>settagmethod (tag, event, newmethod)</TT></h3>
-<A NAME="settagmethod"></A>
-Sets a new tag method to the given pair <EM>(tag, event)</EM> and
-returns the old method.
-If <CODE>newmethod</CODE> is <B>nil</B>,
-then <CODE>settagmethod</CODE> restores the default behavior for the given event.
-This function cannot be used to set a tag method for the ``gc'' event.
-(Such tag methods can only be manipulated by C&nbsp;code.)
-<P>
-<h3> <TT>sort (table [, comp])</TT></h3><A NAME="sort"></A>
-Sorts table elements in a given order, <EM>in-place</EM>,
-from <CODE>table[1]</CODE> to <CODE>table[n]</CODE>,
-where <CODE>n</CODE> is the result of <CODE>getn(table)</CODE> (see Section&nbsp;<A HREF="#getn">6.1</A>).
-If <CODE>comp</CODE> is given,
-then it must be a function that receives two table elements,
-and returns true (that is, a value different from <B>nil</B>)
-when the first is less than the second
-(so that <CODE>not comp(a[i+1], a[i])</CODE> will be true after the sort).
-If <CODE>comp</CODE> is not given,
-then the standard Lua operator <CODE>&lt;</CODE> is used instead.
-<P>
-The sort algorithm is <EM>not</EM> stable
-(that is, elements considered equal by the given order
-may have their relative positions changed by the sort).
-<P>
-<A NAME="pdf-tag"></A>
-<h3> <TT>tag (v)</TT></h3><A NAME="tag"></A>
-Allows Lua programs to test the tag of a value (see Section&nbsp;<A HREF="#TypesSec">3</A>).
-It receives one argument, and returns its tag (a number).
-<P>
-<h3> <TT>tonumber (e [, base])</TT></h3><A NAME="tonumber"></A>
+typically for debugging.
+For formatted output, use <code>format</code> (see <a href="#format">5.3</a>).
+
+<p><h3><code>rawequal (v1, v2)</code></h3>
+Checks whether <code>v1</code> is equal to <code>v2</code>,
+without invoking any metamethod.
+Returns a boolean.
+
+<p><h3><code>rawget (table, index)</code></h3>
+Gets the real value of <code>table[index]</code>,
+without invoking any metamethod.
+<code>table</code> must be a table;
+<code>index</code> is any value different from <B>nil</B>.
+
+<p><h3><code>rawset (table, index, value)</code></h3>
+Sets the real value of <code>table[index]</code> to <code>value</code>,
+without invoking any metamethod.
+<code>table</code> must be a table,
+<code>index</code> is any value different from <B>nil</B>,
+and <code>value</code> is any Lua value.
+
+<p><h3><code>require (packagename)</code></h3>
+
+<p>Loads the given package.
+The function starts by looking into the table <code>_LOADED</code>
+to determine whether <code>packagename</code> is already loaded.
+If it is, then <code>require</code> returns the value that the package
+returned when it was first loaded.
+Otherwise, it searches a path looking for a file to load.
+
+<p>If the global variable <code>LUA_PATH</code> is a string, 
+this string is the path.
+Otherwise, <code>require</code> tries the environment variable <code>LUA_PATH</code>.
+As a last resort, it uses the predefined path <code>"?;?.lua"</code>.
+
+<p>The path is a sequence of <em>templates</em> separated by semicolons.
+For each template, <code>require</code> will change each interrogation
+mark in the template to <code>packagename</code>,
+and then will try to load the resulting file name.
+So, for instance, if the path is
+<PRE>
+  "./?.lua;./?.lc;/usr/local/?/?.lua;/lasttry"
+</PRE>
+a <code>require "mod"</code> will try to load the files
+<code>./mod.lua</code>,
+<code>./mod.lc</code>,
+<code>/usr/local/mod/mod.lua</code>,
+and <code>/lasttry</code>, in that order.
+
+<p>The function stops the search as soon as it can load a file,
+and then it runs the file.
+After that, it associates, in table <code>_LOADED</code>,
+the package name with the value that the package returned,
+and returns that value.
+If the package returns <B>nil</B> (or no value),
+<code>require</code> converts this value to <B>true</B>.
+If the package returns <B>false</B>,
+<code>require</code> also returns <B>false</B>.
+However, as the mark in table <code>_LOADED</code> is <B>false</B>,
+any new attempt to reload the file
+will happen as if the package was not loaded
+(that is, the package will be loaded again).
+
+<p>If there is any error loading or running the file,
+or if it cannot find any file in the path,
+then <code>require</code> signals an error. 
+
+<p>While running a file,
+<code>require</code> defines the global variable <code>_REQUIREDNAME</code>
+with the package name.
+The package being loaded always runs within the global environment.
+
+<p><a name="setfenv"><h3><code>setfenv (f, table)</code></h3></a>
+
+<p>Sets the current environment to be used by the given function.
+<code>f</code> can be a Lua function or a number,
+which specifies the function at that stack level:
+Level 1 is the function calling <code>setfenv</code>.
+
+<p>As a special case, when <code>f</code> is 0 <code>setfenv</code> changes
+the global environment of the running thread.
+
+<p>If the original environment has a <code>"__fenv"</code> field,
+<code>setfenv</code> raises an error.
+
+<p><h3><code>setmetatable (table, metatable)</code></h3>
+
+<p>Sets the metatable for the given table.
+(You cannot change the metatable of a userdata from Lua.)
+If <code>metatable</code> is <B>nil</B>, removes the metatable of the given table.
+If the original metatable has a <code>"__metatable"</code> field,
+raises an error.
+
+<p><h3><code>tonumber (e [, base])</code></h3>
 Tries to convert its argument to a number.
 If the argument is already a number or a string convertible
-to a number, then <CODE>tonumber</CODE> returns that number;
+to a number, then <code>tonumber</code> returns that number;
 otherwise, it returns <B>nil</B>.
-<P>
-An optional argument specifies the base to interpret the numeral.
+
+<p>An optional argument specifies the base to interpret the numeral.
 The base may be any integer between 2 and 36, inclusive.
-In bases above&nbsp;10, the letter `A' (either upper or lower case)
-represents&nbsp;10, `B' represents&nbsp;11, and so forth, with `Z' representing 35.
+In bases above&nbsp;10, the letter `<code>A</code>&acute; (in either upper or lower case)
+represents&nbsp;10, `<code>B</code>&acute; represents&nbsp;11, and so forth,
+with `<code>Z</code>&acute; representing 35.
 In base 10 (the default), the number may have a decimal part,
-as well as an optional exponent part (see Section&nbsp;<A HREF="#coercion">4.2</A>).
+as well as an optional exponent part (see <a href="#coercion">2.2.1</a>).
 In other bases, only unsigned integers are accepted.
-<P>
-<h3> <TT>tostring (e)</TT></h3><A NAME="tostring"></A>
+
+<p><h3><code>tostring (e)</code></h3>
 Receives an argument of any type and
 converts it to a string in a reasonable format.
 For complete control of how numbers are converted,
-use function <CODE>format</CODE>.
-<P>
-<P>
-<P>
-<h3> <TT>tinsert (table [, pos] , value)</TT></h3><A NAME="tinsert"></A>
-<P>
-Inserts element <CODE>value</CODE> at table position <CODE>pos</CODE>,
-shifting other elements to open space, if necessary.
-The default value for <CODE>pos</CODE> is <CODE>n+1</CODE>,
-where <CODE>n</CODE> is the result of <CODE>getn(table)</CODE> (see Section&nbsp;<A HREF="#getn">6.1</A>),
-so that a call <CODE>tinsert(t,x)</CODE> inserts <CODE>x</CODE> at the end
-of table <CODE>t</CODE>.
-This function also sets or increments the field <CODE>n</CODE> of the table
-to <CODE>n+1</CODE>.
-This function is equivalent to the following Lua function,
-except that the table accesses are all <EM>raw</EM>
-(that is, without tag methods):
-<PRE>
-       function tinsert (t, ...)
-         local pos, value
-         local n = getn(t)
-         if arg.n == 1 then
-           pos, value = n+1, arg[1]
-         else
-           pos, value = arg[1], arg[2]
-         end
-         t.n = n+1;
-         for i=n,pos,-1 do
-           t[i+1] = t[i]
-         end
-         t[pos] = value
-       end
-</PRE>
-<P>
-<h3> <TT>tremove (table [, pos])</TT></h3><A NAME="tremove"></A>
-<P>
-Removes from <CODE>table</CODE> the element at position <CODE>pos</CODE>,
-shifting other elements to close the space, if necessary.
-Returns the value of the removed element.
-The default value for <CODE>pos</CODE> is <CODE>n</CODE>,
-where <CODE>n</CODE> is the result of <CODE>getn(table)</CODE> (see Section&nbsp;<A HREF="#getn">6.1</A>),
-so that a call <CODE>tremove(t)</CODE> removes the last element
-of table <CODE>t</CODE>.
-This function also sets or decrements the field <CODE>n</CODE> of the table
-to <CODE>n-1</CODE>.
-<P>
-This function is equivalent to the following Lua function,
-except that the table accesses are all <EM>raw</EM>
-(that is, without tag methods):
-<PRE>
-       function tremove (t, pos)
-         local n = getn(t)
-         if n&lt;=0 then return end
-         pos = pos or n
-         local value = t[pos]
-         for i=pos,n-1 do
-           t[i] = t[i+1]
-         end
-         t[n] = nil
-         t.n = n-1
-         return value
-       end
-</PRE>
-<P>
-<A NAME="pdf-type"></A>
-<h3> <TT>type (v)</TT></h3><A NAME="type"></A>
-Allows Lua programs to test the type of a value.
-It receives one argument, and returns its type, coded as a string.
+use <code>format</code> (see <a href="#format">5.3</a>).
+
+<p>If the metatable of <code>e</code> has a <code>"__tostring"</code> field,
+<code>tostring</code> calls the corresponding value
+with <code>e</code> as argument,
+and uses the result of the call as its result.
+
+<p><a name="pdf-type"><h3><code>type (v)</code></h3></a>
+Returns the type of its only argument, coded as a string.
 The possible results of this function are
-<CODE>"nil"</CODE> (a string, not the value <B>nil</B>),
-<CODE>"number"</CODE>,
-<CODE>"string"</CODE>,
-<CODE>"table"</CODE>,
-<CODE>"function"</CODE>,
-and <CODE>"userdata"</CODE>.
-<P>
-<P>
-<A NAME="6.2"></A>
-<H2>6.2 - String Manipulation</H2>
+<code>"nil"</code> (a string, not the value <B>nil</B>),
+<code>"number"</code>,
+<code>"string"</code>,
+<code>"boolean</code>,
+<code>"table"</code>,
+<code>"function"</code>,
+<code>"thread"</code>,
+and <code>"userdata"</code>.
+
+<p><h3><code>unpack (list)</code></h3>
+Returns all elements from the given list.
+This function is equivalent to
+<PRE>
+  return list[1], list[2], ..., list[n]
+</PRE>
+except that the above code can be written only for a fixed <em>n</em>.
+The number <em>n</em> is the size of the list,
+as defined for the <code>table.getn</code> function.
+
+<p><h3><code>_VERSION</code></h3>
+A global variable (not a function) that
+holds a string containing the current interpreter version.
+The current content of this string is <code>"Lua 5.0"</code>.
+
+<p><h3><code>xpcall (f, err)</code></h3>
+
+<p>This function is similar to <code>pcall</code>,
+except that you can set a new error handler.
+
+<p><code>xpcall</code> calls function <code>f</code> in protected mode,
+using <code>err</code> as the error handler.
+Any error inside <code>f</code> is not propagated;
+instead, <code>xpcall</code> catches the error,
+calls the <code>err</code> function with the original error object,
+and returns a status code.
+Its first result is the status code (a boolean),
+which is true if the call succeeds without errors.
+In such case, <code>xpcall</code> also returns all results from the call,
+after this first result.
+In case of any error,
+<code>xpcall</code> returns false plus the result from <code>err</code>.
+
+<p><h2>5.2 - Coroutine Manipulation</h2>
+
+<p>The operations related to coroutines comprise a sub-library of
+the basic library, and come inside the table .
+See <a href="#coroutine">2.10</a> for a general description of coroutines.
+
+<p><h3><code>coroutine.create (f)</code></h3>
+
+<p>Creates a new coroutine, with body <code>f</code>.
+<code>f</code> must be a Lua function.
+Returns this new coroutine,
+an object with type <code>"thread"</code>.
+
+<p><h3><code>coroutine.resume (co, val1, ...)</code></h3>
+
+<p>Starts or continues the execution of coroutine <code>co</code>.
+The first time you resume a coroutine,
+it starts running its body.
+The arguments <code>val1</code>, ... go as the arguments to the body function.
+If the coroutine has yielded,
+<code>resume</code> restarts it;
+the arguments <code>val1</code>, ... go as the results from the yield.
+
+<p>If the coroutine runs without any errors,
+<code>resume</code> returns <B>true</B> plus any values passed to <code>yield</code>
+(if the coroutine yields) or any values returned by the body function
+(if the coroutine terminates).
+If there is any error,
+<code>resume</code> returns <B>false</B> plus the error message.
+
+<p><h3><code>coroutine.status (co)</code></h3>
+
+<p>Returns the status of coroutine <code>co</code>, as a string:
+<code>"running"</code>,
+if the coroutine is running (that is, it called <code>status</code>);
+<code>"suspended"</code>, if the coroutine is suspended in a call to <code>yield</code>,
+or if it has not started running yet;
+and <code>"dead"</code> if the coroutine has finished its body function,
+or if it has stopped with an error.
+
+<p><h3><code>coroutine.wrap (f)</code></h3>
+
+<p>Creates a new coroutine, with body <code>f</code>.
+<code>f</code> must be a Lua function.
+Returns a function that resumes the coroutine each time it is called.
+Any arguments passed to the function behave as the
+extra arguments to <code>resume</code>.
+Returns the same values returned by <code>resume</code>,
+except the first boolean.
+In case of error, propagates the error.
+
+<p><h3><code>coroutine.yield (val1, ...)</code></h3>
+
+<p>Suspends the execution of the calling coroutine.
+The coroutine cannot be running neither a C function,
+nor a metamethod, nor an iterator.
+Any arguments to <code>yield</code> go as extra results to <code>resume</code>.
+
+<p><h2>5.3 - String Manipulation</h2>
 This library provides generic functions for string manipulation,
-such as finding and extracting substrings and pattern matching.
+such as finding and extracting substrings, and pattern matching.
 When indexing a string in Lua, the first character is at position&nbsp;1
 (not at&nbsp;0, as in C).
-Also,
-indices are allowed to be negative and are intepreted as indexing backwards,
-from the end of the string. Thus, the last character is at position <I>-1</I>,
-and so on.
-<P>
-<h3> <TT>strbyte (s [, i])</TT></h3><A NAME="strbyte"></A>
-Returns the internal numerical code of the <EM>i</EM>-th character of <CODE>s</CODE>.
-If <CODE>i</CODE> is absent, then it is assumed to be&nbsp;1.
-<CODE>i</CODE> may be negative.
-<P>
-Numerical codes are not necessarily portable across platforms.
-<P>
-<h3> <TT>strchar (i1, i2, ...)</TT></h3><A NAME="strchar"></A>
+Indices are allowed to be negative and are interpreted as indexing backwards,
+from the end of the string.
+Thus, the last character is at position <em>-1</em>, and so on.
+
+<p>The string library provides all its functions inside the table
+<code>string</code>.
+
+<p><h3><code>string.byte (s [, i])</code></h3>
+Returns the internal numerical code of the <code>i</code>-th character of <code>s</code>,
+or <B>nil</B> if the index is out of range.
+If <code>i</code> is absent, then it is assumed to be&nbsp;1.
+<code>i</code> may be negative.
+
+<p>Note that numerical codes are not necessarily portable across platforms.
+
+<p><h3><code>string.char (i1, i2, ...)</code></h3>
 Receives 0 or more integers.
 Returns a string with length equal to the number of arguments,
-wherein each character has the internal numerical code equal
+in which each character has the internal numerical code equal
 to its correspondent argument.
-<P>
-Numerical codes are not necessarily portable across platforms.
-<P>
-<h3> <TT>strfind (s, pattern [, init [, plain]])</TT></h3>
-<A NAME="strfind"></A>
-Looks for the first <EM>match</EM> of
-<CODE>pattern</CODE> in <CODE>s</CODE>.
-If it finds one, then <CODE>strfind</CODE> returns the indices of <CODE>s</CODE>
+
+<p>Note that numerical codes are not necessarily portable across platforms.
+
+<p><h3><code>string.dump (function)</code></h3>
+
+<p>Returns a binary representation of the given function,
+so that a later <code>loadstring</code> on that string returns
+a copy of the function.
+<code>function</code> must be a Lua function without upvalues.
+
+<p><h3><code>string.find (s, pattern [, init [, plain]])</code></h3>
+Looks for the first <em>match</em> of
+<code>pattern</code> in the string <code>s</code>.
+If it finds one, then <code>find</code> returns the indices of&nbsp;<code>s</code>
 where this occurrence starts and ends;
 otherwise, it returns <B>nil</B>.
-If the pattern specifies captures (see <CODE>gsub</CODE> below),
+If the pattern specifies captures (see <code>string.gsub</code> below),
 the captured strings are returned as extra results.
-A third, optional numerical argument <CODE>init</CODE> specifies
+A third, optional numerical argument <code>init</code> specifies
 where to start the search;
-its default value is&nbsp;1, and may be negative.
-A value of&nbsp;1 as a fourth, optional argument <CODE>plain</CODE>
+its default value is&nbsp;1 and may be negative.
+A value of <B>true</B> as a fourth, optional argument <code>plain</code>
 turns off the pattern matching facilities,
-so the function does a plain ``find substring'' operation,
-with no characters in <CODE>pattern</CODE> being considered ``magic''.
-Note that if <CODE>plain</CODE> is given, then <CODE>init</CODE> must be given too.
-<P>
-<h3> <TT>strlen (s)</TT></h3><A NAME="strlen"></A>
+so the function does a plain "find substring" operation,
+with no characters in <code>pattern</code> being considered "magic".
+Note that if <code>plain</code> is given, then <code>init</code> must be given too.
+
+<p><h3><code>string.len (s)</code></h3>
 Receives a string and returns its length.
-The empty string <CODE>""</CODE> has length 0.
+The empty string <code>""</code> has length 0.
 Embedded zeros are counted,
-and so <CODE>"a\000b\000c"</CODE> has length 5.
-<P>
-<h3> <TT>strlower (s)</TT></h3><A NAME="strlower"></A>
+so <code>"a\000b\000c"</code> has length 5.
+
+<p><h3><code>string.lower (s)</code></h3>
 Receives a string and returns a copy of that string with all
-upper case letters changed to lower case.
+uppercase letters changed to lowercase.
 All other characters are left unchanged.
-The definition of what is an upper-case
-letter depends on the current locale.
-<P>
-<h3> <TT>strrep (s, n)</TT></h3><A NAME="strrep"></A>
-Returns a string that is the concatenation of <CODE>n</CODE> copies of
-the string <CODE>s</CODE>.
-<P>
-<h3> <TT>strsub (s, i [, j])</TT></h3><A NAME="strsub"></A>
-Returns another string, which is a substring of <CODE>s</CODE>,
-starting at <CODE>i</CODE>  and running until <CODE>j</CODE>;
-<CODE>i</CODE> and <CODE>j</CODE> may be negative,
-If <CODE>j</CODE> is absent, then it is assumed to be equal to <I>-1</I>
+The definition of what is an uppercase letter depends on the current locale.
+
+<p><h3><code>string.rep (s, n)</code></h3>
+Returns a string that is the concatenation of <code>n</code> copies of
+the string <code>s</code>.
+
+<p><h3><code>string.sub (s, i [, j])</code></h3>
+Returns the substring of <code>s</code> that
+starts at <code>i</code>  and continues until <code>j</code>;
+<code>i</code> and <code>j</code> may be negative.
+If <code>j</code> is absent, then it is assumed to be equal to <em>-1</em>
 (which is the same as the string length).
 In particular,
-the call <CODE>strsub(s,1,j)</CODE> returns a prefix of <CODE>s</CODE>
-with length <CODE>j</CODE>,
-and the call <CODE>strsub(s, -i)</CODE> returns a suffix of <CODE>s</CODE>
-with length <CODE>i</CODE>.
-<P>
-<h3> <TT>strupper (s)</TT></h3><A NAME="strupper"></A>
+the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
+with length <code>j</code>,
+and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
+with length <code>i</code>.
+
+<p><h3><code>string.upper (s)</code></h3>
 Receives a string and returns a copy of that string with all
-lower case letters changed to upper case.
+lowercase letters changed to uppercase.
 All other characters are left unchanged.
-The definition of what is a lower case
-letter depends on the current locale.
-<P>
-<h3> <TT>format (formatstring, e1, e2, ...)</TT></h3><A NAME="format"></A>
-<A NAME="format"></A>
+The definition of what is a lowercase letter depends on the current locale.
+
+<p><a name="format"><h3><code>string.format (formatstring, e1, e2, ...)</code></h3></a>
 
 Returns a formatted version of its variable number of arguments
 following the description given in its first argument (which must be a string).
-The format string follows the same rules as the <CODE>printf</CODE> family of
+The format string follows the same rules as the <code>printf</code> family of
 standard C&nbsp;functions.
 The only differences are that the options/modifiers
-<CODE>*</CODE>, <CODE>l</CODE>, <CODE>L</CODE>, <CODE>n</CODE>, <CODE>p</CODE>,
-and <CODE>h</CODE> are not supported,
-and there is an extra option, <CODE>q</CODE>.
-The <CODE>q</CODE> option formats a string in a form suitable to be safely read
+<code>*</code>, <code>l</code>, <code>L</code>, <code>n</code>, <code>p</code>,
+and <code>h</code> are not supported,
+and there is an extra option, <code>q</code>.
+The <code>q</code> option formats a string in a form suitable to be safely read
 back by the Lua interpreter:
 The string is written between double quotes,
-and all double quotes, returns, and backslashes in the string
+and all double quotes, newlines, and backslashes in the string
 are correctly escaped when written.
 For instance, the call
 <PRE>
-       format('%q', 'a string with "quotes" and \n new line')
+       string.format('%q', 'a string with "quotes" and \n new line')
 </PRE>
 will produce the string:
 <PRE>
 "a string with \"quotes\" and \
  new line"
 </PRE>
-<P>
-Conversions can be applied to the <EM>n</EM>-th argument in the argument list,
-rather than the next unused argument.
-In this case, the conversion character <CODE>%</CODE> is replaced
-by the sequence <CODE>%d$</CODE>, where <CODE>d</CODE> is a
-decimal digit in the range [1,9],
-giving the position of the argument in the argument list.
-For instance, the call <CODE>format("%2$d -&gt; %1$03d", 1, 34)</CODE> will
-result in <CODE>"34 -&gt; 001"</CODE>.
-The same argument can be used in more than one conversion.
-<P>
-The options <CODE>c</CODE>, <CODE>d</CODE>, <CODE>E</CODE>, <CODE>e</CODE>, <CODE>f</CODE>,
-<CODE>g</CODE>, <CODE>G</CODE>, <CODE>i</CODE>, <CODE>o</CODE>, <CODE>u</CODE>, <CODE>X</CODE>, and <CODE>x</CODE> all
+
+<p>The options <code>c</code>, <code>d</code>, <code>E</code>, <code>e</code>, <code>f</code>,
+<code>g</code>, <code>G</code>, <code>i</code>, <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code> all
 expect a number as argument,
-whereas <CODE>q</CODE> and <CODE>s</CODE> expect a string.
-The <CODE>*</CODE> modifier can be simulated by building
+whereas <code>q</code> and <code>s</code> expect a string.
+The <code>*</code> modifier can be simulated by building
 the appropriate format string.
-For example, <CODE>"%*g"</CODE> can be simulated with
-<CODE>"%"..width.."g"</CODE>.
-<P>
-Neither the format string nor the string values to be formatted with
-<CODE>%s</CODE> can contain embedded zeros.
-<CODE>%q</CODE> handles string values with embedded zeros.
-<P>
-<h3> <TT>gsub (s, pat, repl [, n])</TT></h3>
-<A NAME="gsub"></A>
-Returns a copy of <CODE>s</CODE>
-in which all occurrences of the pattern <CODE>pat</CODE> have been
-replaced by a replacement string specified by <CODE>repl</CODE>.
-<CODE>gsub</CODE> also returns, as a second value,
+For example, <code>"%*g"</code> can be simulated with
+<code>"%"..width.."g"</code>.
+
+<p>String values to be formatted with
+<code>%s</code> cannot contain embedded zeros.
+
+<p><h3><code>string.gfind (s, pat)</code></h3>
+
+<p>Returns an iterator function that,
+each time it is called,
+returns the next captures from pattern <code>pat</code> over string <code>s</code>.
+
+<p>If <code>pat</code> specifies no captures,
+then the whole match is produced in each call.
+
+<p>As an example, the following loop
+<PRE>
+  s = "hello world from Lua"
+  for w in string.gfind(s, "%a+") do
+    print(w)
+  end
+</PRE>
+will iterate over all the words from string <code>s</code>,
+printing one per line.
+The next example collects all pairs <code>key=value</code> from the
+given string into a table:
+<PRE>
+  t = {}
+  s = "from=world, to=Lua"
+  for k, v in string.gfind(s, "(%w+)=(%w+)") do
+    t[k] = v
+  end
+</PRE>
+
+<p><h3><code>string.gsub (s, pat, repl [, n])</code></h3>
+
+Returns a copy of <code>s</code>
+in which all occurrences of the pattern <code>pat</code> have been
+replaced by a replacement string specified by <code>repl</code>.
+<code>gsub</code> also returns, as a second value,
 the total number of substitutions made.
-<P>
-If <CODE>repl</CODE> is a string, then its value is used for replacement.
-Any sequence in <CODE>repl</CODE> of the form <CODE>%n</CODE>
-with <CODE>n</CODE> between 1 and 9
-stands for the value of the <EM>n</EM>-th captured substring.
-<P>
-If <CODE>repl</CODE> is a function, then this function is called every time a
+
+<p>If <code>repl</code> is a string, then its value is used for replacement.
+Any sequence in <code>repl</code> of the form <code>%</code><em>n</em>,
+with <em>n</em> between 1 and 9,
+stands for the value of the <em>n</em>-th captured substring (see below).
+
+<p>If <code>repl</code> is a function, then this function is called every time a
 match occurs, with all captured substrings passed as arguments,
-in order (see below).
+in order;
+if the pattern specifies no captures,
+then the whole match is passed as a sole argument.
 If the value returned by this function is a string,
 then it is used as the replacement string;
 otherwise, the replacement string is the empty string.
-<P>
-The last, optional parameter <CODE>n</CODE> limits
+
+<p>The optional last parameter <code>n</code> limits
 the maximum number of substitutions to occur.
-For instance, when <CODE>n</CODE> is 1 only the first occurrence of
-<CODE>pat</CODE> is replaced.
-<P>
-Here are some examples:
-<PRE>
-   x = gsub("hello world", "(%w+)", "%1 %1")
-   --&gt; x="hello hello world world"
-<P>
-   x = gsub("hello world", "(%w+)", "%1 %1", 1)
-   --&gt; x="hello hello world"
-<P>
-   x = gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
-   --&gt; x="world hello Lua from"
-<P>
-   x = gsub("home = $HOME, user = $USER", "%$(%w+)", getenv)
-   --&gt; x="home = /home/roberto, user = roberto"  (for instance)
-<P>
-   x = gsub("4+5 = $return 4+5$", "%$(.-)%$", dostring)
-   --&gt; x="4+5 = 9"
-<P>
-   local t = {name="lua", version="4.0"}
-   x = gsub("$name - $version", "%$(%w+)", function (v) return %t[v] end)
-   --&gt; x="lua - 4.0"
-<P>
-   t = {n=0}
-   gsub("first second word", "(%w+)", function (w) tinsert(%t, w) end)
-   --&gt; t={"first", "second", "word"; n=3}
-</PRE>
-<P>
-<P>
-<A NAME="pm"></A>
-<h3>Patterns</h3> 
-<P>
-<H4>Character Class:</H4>
-a <A NAME="character class"><EM>character class</EM></A> is used to represent a set of characters.
+For instance, when <code>n</code> is 1 only the first occurrence of
+<code>pat</code> is replaced.
+
+<p>Here are some examples:
+<PRE>
+   x = string.gsub("hello world", "(%w+)", "%1 %1")
+   --> x="hello hello world world"
+
+   x = string.gsub("hello world", "(%w+)", "%1 %1", 1)
+   --> x="hello hello world"
+
+   x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
+   --> x="world hello Lua from"
+
+   x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
+   --> x="home = /home/roberto, user = roberto"
+
+   x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
+         return loadstring(s)()
+       end)
+   --> x="4+5 = 9"
+
+   local t = {name="lua", version="5.0"}
+   x = string.gsub("$name_$version.tar.gz", "%$(%w+)", function (v)
+         return t[v]
+       end)
+   --> x="lua_5.0.tar.gz"
+</PRE>
+
+<p><a name="pm"><h3>Patterns</h3></a>
+
+<p><p>
+a <em>character class</em> is used to represent a set of characters.
 The following combinations are allowed in describing a character class:
-<DL>
-<DT><B><EM>x</EM></B><DD> (where <EM>x</EM> is any magic characters
-<CODE>^$()%.[]*+-?</CODE>)
-- represents the character <EM>x</EM> itself.
-<DT><B><TT>.</TT></B><DD> - (a dot) represents all characters.
-<DT><B><TT>%a</TT></B><DD> - represents all letters.
-<DT><B><TT>%c</TT></B><DD> - represents all control characters.
-<DT><B><TT>%d</TT></B><DD> - represents all digits.
-<DT><B><TT>%l</TT></B><DD> - represents all lower case letters.
-<DT><B><TT>%p</TT></B><DD> - represents all punctuation characters.
-<DT><B><TT>%s</TT></B><DD> - represents all space characters.
-<DT><B><TT>%u</TT></B><DD> - represents all upper case letters.
-<DT><B><TT>%w</TT></B><DD> - represents all alphanumeric characters.
-<DT><B><TT>%x</TT></B><DD> - represents all hexadecimal digits.
-<DT><B><TT>%z</TT></B><DD> - represents the character with representation 0.
-<DT><B><TT>%<EM>x</TT></EM></B><DD> (where <EM>x</EM> is any non-alphanumeric character)  -
-represents the character <EM>x</EM>.
+<ul>
+<li><b><em>x</em></b> (where <em>x</em> is not one of the magic characters
+<code>^$()%.[]*+-?</code>)
+--- represents the character <em>x</em> itself.
+<li><b><code>.</code></b> --- (a dot) represents all characters.
+<li><b><code>%a</code></b> --- represents all letters.
+<li><b><code>%c</code></b> --- represents all control characters.
+<li><b><code>%d</code></b> --- represents all digits.
+<li><b><code>%l</code></b> --- represents all lowercase letters.
+<li><b><code>%p</code></b> --- represents all punctuation characters.
+<li><b><code>%s</code></b> --- represents all space characters.
+<li><b><code>%u</code></b> --- represents all uppercase letters.
+<li><b><code>%w</code></b> --- represents all alphanumeric characters.
+<li><b><code>%x</code></b> --- represents all hexadecimal digits.
+<li><b><code>%z</code></b> --- represents the character with representation 0.
+<li><b><code>%<em>x</em></code></b> (where <em>x</em> is any non-alphanumeric character)  ---
+represents the character <em>x</em>.
 This is the standard way to escape the magic characters.
-We recommend that any punctuation character (even the non magic)
-should be preceded by a <CODE>%</CODE>
+Any punctuation character (even the non magic)
+can be preceded by a `<code>%</code>&acute;
 when used to represent itself in a pattern.
-<P>
-<DT><B><TT>[char-set</TT></B>]<DD> -
+
+<p><li><b><code>[<em>set</em>]</code></b> ---
 represents the class which is the union of all
-characters in <CODE>char-set</CODE>.
+characters in <em>set</em>.
 A range of characters may be specified by
-separating the end characters of the range with a <CODE>-</CODE>.
-All classes <CODE>%</CODE><EM>x</EM> described above may also be used as
-components in a char-set.
-All other characters in char-set represent themselves.
-For example, <CODE>[%w_]</CODE> (or <CODE>[_%w]</CODE>)
+separating the end characters of the range with a `<code>-</code>&acute;.
+All classes <code>%</code><em>x</em> described above may also be used as
+components in <em>set</em>.
+All other characters in <em>set</em> represent themselves.
+For example, <code>[%w_]</code> (or <code>[_%w]</code>)
 represents all alphanumeric characters plus the underscore,
-<CODE>[0-7]</CODE> represents the octal digits,
-and <CODE>[0-7%l%-]</CODE> represents the octal digits plus
-the lower case letters plus the <CODE>-</CODE> character.
-<P>
-The interaction between ranges and classes is not defined.
-Therefore, patterns like <CODE>[%a-z]</CODE> or <CODE>[a-%%]</CODE>
+<code>[0-7]</code> represents the octal digits,
+and <code>[0-7%l%-]</code> represents the octal digits plus
+the lowercase letters plus the `<code>-</code>&acute; character.
+
+<p>The interaction between ranges and classes is not defined.
+Therefore, patterns like <code>[%a-z]</code> or <code>[a-%%]</code>
 have no meaning.
-<P>
-<DT><B><TT>[^char-set</TT></B>]<DD> -
-represents the complement of <CODE>char-set</CODE>,
-where <CODE>char-set</CODE> is interpreted as above.
-</DL>
-For all classes represented by single letters (<CODE>%a</CODE>, <CODE>%c</CODE>, ...),
-the corresponding upper-case letter represents the complement of the class.
-For instance, <CODE>%S</CODE> represents all non-space characters.
-<P>
-The definitions of letter, space, etc. depend on the current locale.
-In particular, the class <CODE>[a-z]</CODE> may not be equivalent to <CODE>%l</CODE>.
+
+<p><li><b><code>[^<em>set</em>]</code></b> ---
+represents the complement of <em>set</em>,
+where <em>set</em> is interpreted as above.
+</ul>
+For all classes represented by single letters (<code>%a</code>, <code>%c</code>, etc.),
+the corresponding uppercase letter represents the complement of the class.
+For instance, <code>%S</code> represents all non-space characters.
+
+<p>The definitions of letter, space, and other character groups
+depend on the current locale.
+In particular, the class <code>[a-z]</code> may not be equivalent to <code>%l</code>.
 The second form should be preferred for portability.
-<P>
-<H4>Pattern Item:</H4>
-a <A NAME="pattern item"><EM>pattern item</EM></A> may be
-<UL>
-<LI>
+
+<p><p>
+a <em>pattern item</em> may be
+<ul>
+<li> 
 a single character class,
 which matches any single character in the class;
-<LI>
-a single character class followed by <CODE>*</CODE>,
+<li> 
+a single character class followed by `<code>*</code>&acute;,
 which matches 0 or more repetitions of characters in the class.
 These repetition items will always match the longest possible sequence;
-<LI>
-a single character class followed by <CODE>+</CODE>,
+<li> 
+a single character class followed by `<code>+</code>&acute;,
 which matches 1 or more repetitions of characters in the class.
 These repetition items will always match the longest possible sequence;
-<LI>
-a single character class followed by <CODE>-</CODE>,
+<li> 
+a single character class followed by `<code>-</code>&acute;,
 which also matches 0 or more repetitions of characters in the class.
-Unlike <CODE>*</CODE>,
-these repetition items will always match the shortest possible sequence;
-<LI>
-a single character class followed by <CODE>?</CODE>,
+Unlike `<code>*</code>&acute;,
+these repetition items will always match the <em>shortest</em> possible sequence;
+<li> 
+a single character class followed by `<code>?</code>&acute;,
 which matches 0 or 1 occurrence of a character in the class;
-<LI>
-<TT>%<EM>n</TT></EM>, for <EM>n</EM> between 1 and 9;
-such item matches a sub-string equal to the <EM>n</EM>-th captured string
+<li> 
+<code>%<em>n</em></code>, for <em>n</em> between 1 and 9;
+such item matches a substring equal to the <em>n</em>-th captured string
 (see below);
-<LI>
-<TT>%b<EM>xy</TT></EM>, where <EM>x</EM> and <EM>y</EM> are two distinct characters;
-such item matches strings that start with&nbsp;<EM>x</EM>, end with&nbsp;<EM>y</EM>,
-and where the <EM>x</EM> and <EM>y</EM> are <EM>balanced</EM>.
+<li> 
+<code>%b<em>xy</em></code>, where <em>x</em> and <em>y</em> are two distinct characters;
+such item matches strings that start with&nbsp;<em>x</em>, end with&nbsp;<em>y</em>,
+and where the <em>x</em> and <em>y</em> are <em>balanced</em>.
 This means that, if one reads the string from left to right,
-counting <I>+1</I> for an <EM>x</EM> and <I>-1</I> for a <EM>y</EM>,
-the ending <EM>y</EM> is the first <EM>y</EM> where the count reaches 0.
-For instance, the item <CODE>%b()</CODE> matches expressions with
+counting <em>+1</em> for an <em>x</em> and <em>-1</em> for a <em>y</em>,
+the ending <em>y</em> is the first <em>y</em> where the count reaches 0.
+For instance, the item <code>%b()</code> matches expressions with
 balanced parentheses.
-</UL>
-<P>
-<H4>Pattern:</H4>
-a <A NAME="pattern"><EM>pattern</EM></A> is a sequence of pattern items.
-A <CODE>^</CODE> at the beginning of a pattern anchors the match at the
+</ul>
+
+<p><p>
+a <em>pattern</em> is a sequence of pattern items.
+A `<code>^</code>&acute; at the beginning of a pattern anchors the match at the
 beginning of the subject string.
-A <CODE>$</CODE> at the end of a pattern anchors the match at the
+A `<code>$</code>&acute; at the end of a pattern anchors the match at the
 end of the subject string.
 At other positions,
-<CODE>^</CODE> and <CODE>$</CODE> have no special meaning and represent themselves.
-<P>
-<H4>Captures:</H4>
-A pattern may contain sub-patterns enclosed in parentheses,
-they describe <A NAME="captures"><EM>captures</EM></A>.
-When a match succeeds, the sub-strings of the subject string
-that match captures are stored (<EM>captured</EM>) for future use.
+`<code>^</code>&acute; and `<code>$</code>&acute; have no special meaning and represent themselves.
+
+<p><p>
+A pattern may contain sub-patterns enclosed in parentheses;
+they describe <em>captures</em>.
+When a match succeeds, the substrings of the subject string
+that match captures are stored (<em>captured</em>) for future use.
 Captures are numbered according to their left parentheses.
-For instance, in the pattern <CODE>"(a*(.)%w(%s*))"</CODE>,
-the part of the string matching <CODE>"a*(.)%w(%s*)"</CODE> is
+For instance, in the pattern <code>"(a*(.)%w(%s*))"</code>,
+the part of the string matching <code>"a*(.)%w(%s*)"</code> is
 stored as the first capture (and therefore has number&nbsp;1);
-the character matching <CODE>.</CODE> is captured with number&nbsp;2,
-and the part matching <CODE>%s*</CODE> has number&nbsp;3.
-<P>
-A pattern cannot contain embedded zeros.  Use <CODE>%z</CODE> instead.
-<P>
-<P>
-<A NAME="mathlib"></A>
-<A NAME="6.3"></A>
-<H2>6.3 - Mathematical Functions</H2> 
-<P>
-This library is an interface to some functions of the standard C&nbsp;math library.
-In addition, it registers a tag method for the binary operator <CODE>^</CODE> that
-returns <I>x^y</I> when applied to numbers <CODE>x^y</CODE>.
-<P>
+the character matching <code>.</code> is captured with number&nbsp;2,
+and the part matching <code>%s*</code> has number&nbsp;3.
+
+<p>As a special case, the empty capture <code>()</code> captures
+the current string position (a number).
+For instance, if we apply the pattern <code>"()aa()"</code> on the
+string <code>"flaaap"</code>, there will be two captures: 3 and 5.
+
+<p>A pattern cannot contain embedded zeros.  Use <code>%z</code> instead.
+
+<p><h2>5.4 - Table Manipulation</h2>
+This library provides generic functions for table manipulation.
+It provides all its functions inside the table <code>table</code>.
+
+<p>Most functions in the table library assume that the table
+represents an array or a list.
+For those functions, an important concept is the <em>size</em> of the array.
+There are three ways to specify that size:
+<ul>
+<li> the field <code>"n"</code> ---
+When the table has a field <code>"n"</code> with a numerical value,
+that value is assumed as its size.
+<li> <code>setn</code> ---
+You can call the <code>table.setn</code> function to explicitly set
+the size of a table.
+<li> implicit size ---
+Otherwise, the size of the object is one less the first integer index
+with a <B>nil</B> value.
+</ul>
+For more details, see the descriptions of the <code>table.getn</code> and
+<code>table.setn</code> functions.
+
+<p><h3><code>table.concat (table [, sep [, i [, j]]])</code></h3>
+
+Returns <code>table[i]..sep..table[i+1] ... sep..table[j]</code>.
+The default value for <code>sep</code> is the empty string,
+the default for <code>i</code> is 1,
+and the default for <code>j</code> is the size of the table.
+If <code>i</code> is greater than <code>j</code>, returns the empty string.
+
+<p><h3><code>table.foreach (table, f)</code></h3>
+Executes the given <code>f</code> over all elements of <code>table</code>.
+For each element, <code>f</code> is called with the index and
+respective value as arguments.
+If <code>f</code> returns a non-<B>nil</B> value,
+then the loop is broken, and this value is returned
+as the final value of <code>foreach</code>.
+
+<p>See the <code>next</code> function for extra information about table traversals.
+
+<p><h3><code>table.foreachi (table, f)</code></h3>
+Executes the given <code>f</code> over the
+numerical indices of <code>table</code>.
+For each index, <code>f</code> is called with the index and
+respective value as arguments.
+Indices are visited in sequential order,
+from&nbsp;1 to <code>n</code>,
+where <code>n</code> is the size of the table (see <a href="#getn">5.4</a>).
+If <code>f</code> returns a non-<B>nil</B> value,
+then the loop is broken and this value is returned
+as the result of <code>foreachi</code>.
+
+<p><a name="getn"><h3><code>table.getn (table)</code></h3></a>
+Returns the size of a table, when seen as a list.
+If the table has an <code>n</code> field with a numeric value,
+this value is the size of the table.
+Otherwise, if there was a previous call
+to <code>table.setn</code> over this table,
+the respective value is returned.
+Otherwise, the size is one less the first integer index with
+a <B>nil</B> value.
+
+<p><h3><code>table.sort (table [, comp])</code></h3>
+Sorts table elements in a given order, <em>in-place</em>,
+from <code>table[1]</code> to <code>table[n]</code>,
+where <code>n</code> is the size of the table (see <a href="#getn">5.4</a>).
+If <code>comp</code> is given,
+then it must be a function that receives two table elements,
+and returns true
+when the first is less than the second
+(so that <code>not comp(a[i+1],a[i])</code> will be true after the sort).
+If <code>comp</code> is not given,
+then the standard Lua operator <code>&#060;</code> is used instead.
+
+<p>The sort algorithm is <em>not</em> stable,
+that is, elements considered equal by the given order
+may have their relative positions changed by the sort.
+
+<p><h3><code>table.insert (table, [pos,] value)</code></h3>
+
+<p>Inserts element <code>value</code> at position <code>pos</code> in <code>table</code>,
+shifting up other elements to open space, if necessary.
+The default value for <code>pos</code> is <code>n+1</code>,
+where <code>n</code> is the size of the table (see <a href="#getn">5.4</a>),
+so that a call <code>table.insert(t,x)</code> inserts <code>x</code> at the end
+of table <code>t</code>.
+This function also updates the size of the table by
+calling <code>table.setn(table, n+1)</code>.
+
+<p><h3><code>table.remove (table [, pos])</code></h3>
+
+<p>Removes from <code>table</code> the element at position <code>pos</code>,
+shifting down other elements to close the space, if necessary.
+Returns the value of the removed element.
+The default value for <code>pos</code> is <code>n</code>,
+where <code>n</code> is the size of the table (see <a href="#getn">5.4</a>),
+so that a call <code>table.remove(t)</code> removes the last element
+of table <code>t</code>.
+This function also updates the size of the table by
+calling <code>table.setn(table, n-1)</code>.
+
+<p><h3><code>table.setn (table, n)</code></h3>
+
+<p>Updates the size of a table.
+If the table has a field <code>"n"</code> with a numerical value,
+that value is changed to the given <code>n</code>.
+Otherwise, it updates an internal state
+so that subsequent calls to <code>table.getn(table)</code> return <code>n</code>.
+
+<p><a name="mathlib"><h2>5.5 - Mathematical Functions</h2></a>
+
+<p>This library is an interface to most of the functions of the
+standard C&nbsp;math library.
+(Some have slightly different names.)
+It provides all its functions inside the table <code>math</code>.
+In addition,
+it registers the global <code>__pow</code>
+for the binary exponentiation operator <code>^</code>,
+so that <code>x^y</code> returns <em>x<sup>y</sup></em>.
 The library provides the following functions:
-<A NAME="abs"></A><A NAME="acos"></A><A NAME="asin"></A><A NAME="atan"></A>
-<A NAME="atan2"></A><A NAME="ceil"></A><A NAME="cos"></A><A NAME="def"></A><A NAME="exp"></A>
-<A NAME="floor"></A><A NAME="log"></A><A NAME="log10"></A><A NAME="max"></A><A NAME="min"></A>
-<A NAME="mod"></A><A NAME="rad"></A><A NAME="sin"></A><A NAME="sqrt"></A><A NAME="tan"></A>
-<A NAME="frexp"></A><A NAME="ldexp"></A><A NAME="random"></A><A NAME="randomseed"></A>
+
+
+
+
+
+
+
+
+
 <PRE>
-       abs  acos  asin  atan  atan2  ceil  cos  deg    exp    floor   log  log10
-       max  min   mod   rad   sin    sqrt  tan  frexp  ldexp  random  randomseed
+       math.abs     math.acos    math.asin    math.atan    math.atan2
+       math.ceil    math.cos     math.deg     math.exp     math.floor
+       math.log     math.log10   math.max     math.min     math.mod
+       math.pow     math.rad     math.sin     math.sqrt    math.tan
+       math.frexp   math.ldexp   math.random  math.randomseed
 </PRE>
-plus a global variable <A NAME="PI"><TT>PI</TT></A>.
+plus a variable <code>math.pi</code>.
 Most of them
-are only interfaces to the homonymous functions in the C&nbsp;library,
-except that, for the trigonometric functions,
-all angles are expressed in <EM>degrees</EM>, not radians.
-The functions <CODE>deg</CODE> and <CODE>rad</CODE> can be used to convert
+are only interfaces to the corresponding functions in the C&nbsp;library.
+All trigonometric functions work in radians
+(previous versions of Lua used degrees).
+The functions <code>math.deg</code> and <code>math.rad</code> convert
 between radians and degrees.
-<P>
-The function <CODE>max</CODE> returns the maximum
+
+<p>The function <code>math.max</code> returns the maximum
 value of its numeric arguments.
-Similarly, <CODE>min</CODE> computes the minimum.
+Similarly, <code>math.min</code> computes the minimum.
 Both can be used with 1, 2, or more arguments.
-<P>
-The functions <CODE>random</CODE> and <CODE>randomseed</CODE> are interfaces to
-the simple random generator functions <CODE>rand</CODE> and <CODE>srand</CODE>,
-provided by ANSI C.
+
+<p>The functions <code>math.random</code> and <code>math.randomseed</code>
+are interfaces to the simple random generator functions
+<code>rand</code> and <code>srand</code> that are provided by ANSI&nbsp;C.
 (No guarantees can be given for their statistical properties.)
-The function <CODE>random</CODE>, when called without arguments,
-returns a pseudo-random real number in the range <I>[0,1)</I>.
-When called with a number <I>n</I>,
-<CODE>random</CODE> returns a pseudo-random integer in the range <I>[1,n]</I>.
-When called with two arguments, <I>l</I> and <I>u</I>,
-<CODE>random</CODE> returns a pseudo-random integer in the range <I>[l,u]</I>.
-<P>
-<P>
-<A NAME="libio"></A>
-<A NAME="6.4"></A>
-<H2>6.4 - I/O Facilities</H2> 
-<P>
-All input and output operations in Lua are done, by default,
-over two <A NAME="file handles"><EM>file handles</EM></A>, one for reading and one for writing.
-These handles are stored in two Lua global variables,
-called <CODE>_INPUT</CODE> and <CODE>_OUTPUT</CODE>.
-The global variables
-<CODE>_STDIN</CODE>, <CODE>_STDOUT</CODE>, and <CODE>_STDERR</CODE>
-are initialized with file descriptors for
-<CODE>stdin</CODE>, <CODE>stdout</CODE>, and <CODE>stderr</CODE>.
-Initially, <CODE>_INPUT=_STDIN</CODE> and <CODE>_OUTPUT=_STDOUT</CODE>.
-<A NAME="_INPUT"></A><A NAME="_OUTPUT"></A>
-<A NAME="_STDIN"></A><A NAME="_STDOUT"></A><A NAME="_STDERR"></A>
-<P>
-A file handle is a userdata containing the file stream (<CODE>FILE*</CODE>),
-and with a distinctive tag created by the I/O library.
-<P>
-Unless otherwise stated,
-all I/O functions return <B>nil</B> on failure and
-some value different from <B>nil</B> on success.
-<P>
-<h3> <TT>openfile (filename, mode)</TT></h3><A NAME="openfile"></A>
-<P>
-This function opens a file,
-in the mode specified in the string <CODE>mode</CODE>.
+When called without arguments,
+<code>math.random</code> returns a pseudo-random real number
+in the range <em>[0,1)</em>.  
+When called with a number <em>n</em>,
+<code>math.random</code> returns a pseudo-random integer in the range <em>[1,n]</em>.
+When called with two arguments, <em>l</em> and <em>u</em>,
+<code>math.random</code> returns a pseudo-random integer in the range <em>[l,u]</em>.
+The <code>math.randomseed</code> function sets a "seed"
+for the pseudo-random generator:
+Equal seeds produce equal sequences of numbers.
+
+<p><a name="libio"><h2>5.6 - Input and Output Facilities</h2></a>
+
+<p>The I/O library provides two different styles for file manipulation.
+The first one uses implicit file descriptors,
+that is, there are operations to set a default input file and a
+default output file,
+and all input/output operations are over those default files.
+The second style uses explicit file descriptors.
+
+<p>When using implicit file descriptors,
+all operations are supplied by table <code>io</code>.
+When using explicit file descriptors,
+the operation <code>io.open</code> returns a file descriptor
+and then all operations are supplied as methods by the file descriptor.
+
+<p>The table <code>io</code> also provides
+three predefined file descriptors with their usual meanings from C:
+<code>io.stdin</code>, <code>io.stdout</code>, and <code>io.stderr</code>.
+
+<p>A file handle is a userdata containing the file stream (<code>FILE*</code>),
+with a distinctive metatable created by the I/O library.
+
+<p>Unless otherwise stated,
+all I/O functions return <B>nil</B> on failure
+(plus an error message as a second result)
+and some value different from <B>nil</B> on success.
+
+<p><h3><code>io.close ([file])</code></h3>
+
+<p>Equivalent to <code>file:close()</code>.
+Without a <code>file</code>, closes the default output file.
+
+<p><h3><code>io.flush ()</code></h3>
+
+<p>Equivalent to <code>file:flush</code> over the default output file.
+
+<p><h3><code>io.input ([file])</code></h3>
+
+<p>When called with a file name, it opens the named file (in text mode),
+and sets its handle as the default input file.
+When called with a file handle,
+it simply sets that file handle as the default input file.
+When called without parameters,
+it returns the current default input file.
+
+<p>In case of errors this function raises the error,
+instead of returning an error code.
+
+<p><h3><code>io.lines ([filename])</code></h3>
+
+<p>Opens the given file name in read mode
+and returns an iterator function that,
+each time it is called,
+returns a new line from the file.
+Therefore, the construction
+<PRE>
+       for line in io.lines(filename) do ... end
+</PRE>
+will iterate over all lines of the file.
+When the iterator function detects the end of file,
+it returns <B>nil</B> (to finish the loop) and automatically closes the file.
+
+<p>The call <code>io.lines()</code> (without a file name) is equivalent
+to <code>io.input():lines()</code>, that is, it iterates over the
+lines of the default input file.
+
+<p><h3><code>io.open (filename [, mode])</code></h3>
+
+<p>This function opens a file,
+in the mode specified in the string <code>mode</code>.
 It returns a new file handle,
-or, in case of errors, <B>nil</B> plus a string describing the error.
-This function does not modify either <CODE>_INPUT</CODE> or <CODE>_OUTPUT</CODE>.
-<P>
-The <CODE>mode</CODE> string can be any of the following:
-<DL>
-<DT><B>``r''</B><DD> read mode;
-<DT><B>``w''</B><DD> write mode;
-<DT><B>``a''</B><DD> append mode;
-<DT><B>``r+''</B><DD> update mode, all previous data is preserved;
-<DT><B>``w+''</B><DD> update mode, all previous data is erased;
-<DT><B>``a+''</B><DD> append update mode, previous data is preserved,
+or, in case of errors, <B>nil</B> plus an error message.
+
+<p>The <code>mode</code> string can be any of the following:
+<ul>
+<li><b>"r"</b> read mode (the default);
+<li><b>"w"</b> write mode;
+<li><b>"a"</b> append mode;
+<li><b>"r+"</b> update mode, all previous data is preserved;
+<li><b>"w+"</b> update mode, all previous data is erased;
+<li><b>"a+"</b> append update mode, previous data is preserved,
   writing is only allowed at the end of file.
-</DL>
-The <CODE>mode</CODE> string may also have a <CODE>b</CODE> at the end,
+</ul>
+The <code>mode</code> string may also have a <code>b</code> at the end,
 which is needed in some systems to open the file in binary mode.
-This string is exactlty what is used in the standard&nbsp;C function <CODE>fopen</CODE>.
-<P>
-<h3> <TT>closefile (handle)</TT></h3><A NAME="closefile"></A>
-<P>
-This function closes the given file.
-It does not modify either <CODE>_INPUT</CODE> or <CODE>_OUTPUT</CODE>.
-<P>
-<h3> <TT>readfrom (filename)</TT></h3><A NAME="readfrom"></A>
-<P>
-This function may be called in two ways.
-When called with a file name, it opens the named file,
-sets its handle as the value of <CODE>_INPUT</CODE>,
-and returns this value.
-It does not close the current input file.
-When called without parameters,
-it closes the <CODE>_INPUT</CODE> file,
-and restores <CODE>stdin</CODE> as the value of <CODE>_INPUT</CODE>.
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-If <CODE>filename</CODE> starts with a <CODE>|</CODE>,
-then a <A NAME="piped input">piped input</A> is opened, via function <A NAME="popen"><TT>popen</TT></A>.
-Not all systems implement pipes.
-Moreover,
-the number of files that can be open at the same time is
-usually limited and depends on the system.
-<P>
-<h3> <TT>writeto (filename)</TT></h3><A NAME="writeto"></A>
-<P>
-This function may be called in two ways.
-When called with a file name,
-it opens the named file,
-sets its handle as the value of <CODE>_OUTPUT</CODE>,
-and returns this value.
-It does not close the current output file.
-Note that, if the file already exists,
-then it will be <EM>completely erased</EM> with this operation.
-When called without parameters,
-this function closes the <CODE>_OUTPUT</CODE> file,
-and restores <CODE>stdout</CODE> as the value of <CODE>_OUTPUT</CODE>.
-<A NAME="closing a file"></A>
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-If <CODE>filename</CODE> starts with a <CODE>|</CODE>,
-then a <A NAME="piped input">piped input</A> is opened, via function <A NAME="popen"><TT>popen</TT></A>.
-Not all systems implement pipes.
-Moreover,
-the number of files that can be open at the same time is
-usually limited and depends on the system.
-<P>
-<h3> <TT>appendto (filename)</TT></h3><A NAME="appendto"></A>
-<P>
-Opens a file named <CODE>filename</CODE> and sets it as the
-value of <CODE>_OUTPUT</CODE>.
-Unlike the <CODE>writeto</CODE> operation,
-this function does not erase any previous contents of the file;
-instead, anything written to the file is appended to its end.
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-<h3> <TT>remove (filename)</TT></h3><A NAME="remove"></A>
-<P>
-Deletes the file with the given name.
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-<h3> <TT>rename (name1, name2)</TT></h3><A NAME="rename"></A>
-<P>
-Renames file named <CODE>name1</CODE> to <CODE>name2</CODE>.
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-<h3> <TT>flush ([filehandle])</TT></h3><A NAME="flush"></A>
-<P>
-Saves any written data to the given file.
-If <CODE>filehandle</CODE> is not specified,
-then <CODE>flush</CODE> flushes all open files.
-If this function fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-<h3> <TT>seek (filehandle [, whence] [, offset])</TT></h3><A NAME="seek"></A>
-<P>
-Sets and gets the file position,
-measured in bytes from the beginning of the file,
-to the position given by <CODE>offset</CODE> plus a base
-specified by the string <CODE>whence</CODE>, as follows:
-<DL>
-<DT><B>``set''</B><DD> base is position 0 (beginning of the file);
-<DT><B>``cur''</B><DD> base is current position;
-<DT><B>``end''</B><DD> base is end of file;
-</DL>
-In case of success, function <CODE>seek</CODE> returns the final file position,
-measured in bytes from the beginning of the file.
-If the call fails, it returns <B>nil</B>,
-plus a string describing the error.
-<P>
-The default value for <CODE>whence</CODE> is <CODE>"cur"</CODE>,
-and for <CODE>offset</CODE> is 0.
-Therefore, the call <CODE>seek(file)</CODE> returns the current
-file position, without changing it;
-the call <CODE>seek(file, "set")</CODE> sets the position to the
-beginning of the file (and returns 0);
-and the call <CODE>seek(file, "end")</CODE> sets the position to the
-end of the file, and returns its size.
-<P>
-<h3> <TT>tmpname ()</TT></h3><A NAME="tmpname"></A>
-<P>
-Returns a string with a file name that can safely
-be used for a temporary file.
-The file must be explicitly opened before its use
-and removed when no longer needed.
-<P>
-<h3> <TT>read ([filehandle,] format1, ...)</TT></h3><A NAME="read"></A>
-<P>
-Reads file <CODE>_INPUT</CODE>,
-or <CODE>filehandle</CODE> if this argument is given,
+This string is exactly what is used in the standard&nbsp;C function <code>fopen</code>.
+
+<p><h3><code>io.output ([file])</code></h3>
+
+<p>Similar to <code>io.input</code>, but operates over the default output file.
+
+<p><h3><code>io.read (format1, ...)</code></h3>
+
+<p>Equivalent to <code>io.input():read</code>.
+
+<p><h3><code>io.tmpfile ()</code></h3>
+
+<p>Returns a handle for a temporary file.
+This file is open in update mode
+and it is automatically removed when the program ends.
+
+<p><h3><code>io.type (obj)</code></h3>
+
+<p>Checks whether <code>obj</code> is a valid file handle.
+Returns the string <code>"file"</code> if <code>obj</code> is an open file handle,
+<code>"closed file"</code> if <code>obj</code> is a closed file handle,
+and <B>nil</B> if <code>obj</code> is not a file handle.
+
+<p><h3><code>io.write (value1, ...)</code></h3>
+
+<p>Equivalent to <code>io.output():write</code>.
+
+<p><h3><code>file:close ()</code></h3>
+
+<p>Closes <code>file</code>.
+
+<p><h3><code>file:flush ()</code></h3>
+
+<p>Saves any written data to <code>file</code>.
+
+<p><h3><code>file:lines ()</code></h3>
+
+<p>Returns an iterator function that,
+each time it is called,
+returns a new line from the file.
+Therefore, the construction
+<PRE>
+       for line in file:lines() do ... end
+</PRE>
+will iterate over all lines of the file.
+(Unlike <code>io.lines</code>, this function does not close the file
+when the loop ends.)
+
+<p><h3><code>file:read (format1, ...)</code></h3>
+
+<p>Reads the file <code>file</code>,
 according to the given formats, which specify what to read.
 For each format,
 the function returns a string (or a number) with the characters read,
 or <B>nil</B> if it cannot read data with the specified format.
 When called without formats,
-it uses a default format that reads the next line
+it uses a default format that reads the entire next line
 (see below).
-<P>
-The available formats are
-<DL>
-<DT><B>``*n''</B><DD> reads a number;
+
+<p>The available formats are
+<ul>
+<li><b>"*n"</b> reads a number;
 this is the only format that returns a number instead of a string.
-<DT><B>``*l''</B><DD> reads the next line
-(skipping the end of line), or <B>nil</B> on end of file.
-This is the default format.
-<DT><B>``*a''</B><DD> reads the whole file, starting at the current position.
+<li><b>"*a"</b> reads the whole file, starting at the current position.
 On end of file, it returns the empty string.
-<DT><B>``*w''</B><DD> reads the next word
-(maximal sequence of non--white-space characters),
-skipping spaces if necessary, or <B>nil</B> on end of file.
-<DT><B><EM>number</EM></B><DD> reads a string with up to that number of characters,
+<li><b>"*l"</b> reads the next line (skipping the end of line),
+returning <B>nil</B> on end of file.
+This is the default format.
+<li><b><em>number</em></b> reads a string with up to that number of characters,
+returning <B>nil</B> on end of file.
+If number is zero,
+it reads nothing and returns an empty string,
 or <B>nil</B> on end of file.
-</DL>
-<P>
-<h3> <TT>write ([filehandle, ] value1, ...)</TT></h3><A NAME="write"></A>
-<P>
-Writes the value of each of its arguments to
-file <CODE>_OUTPUT</CODE>,
-or to <CODE>filehandle</CODE> if this argument is given.
-The arguments must be strings or numbers.
-To write other values,
-use <CODE>tostring</CODE> or <CODE>format</CODE> before <CODE>write</CODE>.
+</ul>
+
+<p><h3><code>file:seek ([whence] [, offset])</code></h3>
+
+<p>Sets and gets the file position,
+measured from the beginning of the file,
+to the position given by <code>offset</code> plus a base
+specified by the string <code>whence</code>, as follows:
+<ul>
+<li><b>"set"</b> base is position 0 (beginning of the file);
+<li><b>"cur"</b> base is current position;
+<li><b>"end"</b> base is end of file;
+</ul>
+In case of success, function <code>seek</code> returns the final file position,
+measured in bytes from the beginning of the file.
 If this function fails, it returns <B>nil</B>,
 plus a string describing the error.
-<P>
-<A NAME="libiosys"></A>
-<A NAME="6.5"></A>
-<H2>6.5 - System Facilities</H2> 
-<P>
-<h3> <TT>clock ()</TT></h3><A NAME="clock"></A>
-<P>
-Returns an approximation of the amount of CPU time
+
+<p>The default value for <code>whence</code> is <code>"cur"</code>,
+and for <code>offset</code> is 0.
+Therefore, the call <code>file:seek()</code> returns the current
+file position, without changing it;
+the call <code>file:seek("set")</code> sets the position to the
+beginning of the file (and returns 0);
+and the call <code>file:seek("end")</code> sets the position to the
+end of the file, and returns its size.
+
+<p><h3><code>file:write (value1, ...)</code></h3>
+
+<p>Writes the value of each of its arguments to
+the filehandle <code>file</code>.
+The arguments must be strings or numbers.
+To write other values,
+use <code>tostring</code> or <code>string.format</code> before <code>write</code>.
+
+<p><a name="libiosys"><h2>5.7 - Operating System Facilities</h2></a>
+
+<p>This library is implemented through table <code>os</code>.
+
+<p><h3><code>os.clock ()</code></h3>
+
+<p>Returns an approximation of the amount of CPU time
 used by the program, in seconds.
-<P>
-<h3> <TT>date ([format])</TT></h3><A NAME="date"></A>
-<P>
-Returns a string containing date and time
-formatted according to the given string <CODE>format</CODE>,
-following the same rules of the ANSI&nbsp;C function <CODE>strftime</CODE>.
-When called without arguments,
-it returns a reasonable date and time representation that depends on
-the host system and on the current locale.
-<P>
-<h3> <TT>execute (command)</TT></h3><A NAME="execute"></A>
-<P>
-This function is equivalent to the C&nbsp;function <CODE>system</CODE>.
-It passes <CODE>command</CODE> to be executed by an operating system shell.
+
+<p><h3><code>os.date ([format [, time]])</code></h3>
+
+<p>Returns a string or a table containing date and time,
+formatted according to the given string <code>format</code>.
+
+<p>If the <code>time</code> argument is present,
+this is the time to be formatted
+(see the <code>os.time</code> function for a description of this value).
+Otherwise, <code>date</code> formats the current time.
+
+<p>If <code>format</code> starts with `<code>!</code>&acute;,
+then the date is formatted in Coordinated Universal Time.
+After that optional character,
+if <code>format</code> is <code>*t</code>,
+then <code>date</code> returns a table with the following fields:
+<code>year</code> (four digits), <code>month</code> (1--12), <code>day</code> (1--31),
+<code>hour</code> (0--23), <code>min</code> (0--59), <code>sec</code> (0--61),
+<code>wday</code> (weekday, Sunday is 1),
+<code>yday</code> (day of the year),
+and <code>isdst</code> (daylight saving flag, a boolean).
+
+<p>If <code>format</code> is not <code>*t</code>,
+then <code>date</code> returns the date as a string,
+formatted according with the same rules as the C&nbsp;function <code>strftime</code>.
+
+<p>When called without arguments,
+<code>date</code> returns a reasonable date and time representation that depends on
+the host system and on the current locale
+(that is, <code>os.date()</code> is equivalent to <code>os.date("%c")</code>).
+
+<p><h3><code>os.difftime (t2, t1)</code></h3>
+
+<p>Returns the number of seconds from time <code>t1</code> to time <code>t2</code>.
+In Posix, Windows, and some other systems,
+this value is exactly <code>t2</code><em>-</em><code>t1</code>.
+
+<p><h3><code>os.execute (command)</code></h3>
+
+<p>This function is equivalent to the C&nbsp;function <code>system</code>.
+It passes <code>command</code> to be executed by an operating system shell.
 It returns a status code, which is system-dependent.
-<P>
-<h3> <TT>exit ([code])</TT></h3><A NAME="exit"></A>
-<P>
-Calls the C&nbsp;function <CODE>exit</CODE>,
-with an optional <CODE>code</CODE>,
-to terminate the program.
-The default value for <CODE>code</CODE> is the success code.
-<P>
-<h3> <TT>getenv (varname)</TT></h3><A NAME="getenv"></A>
-<P>
-Returns the value of the process environment variable <CODE>varname</CODE>,
+
+<p><h3><code>os.exit ([code])</code></h3>
+
+<p>Calls the C&nbsp;function <code>exit</code>,
+with an optional <code>code</code>,
+to terminate the host program.
+The default value for <code>code</code> is the success code.
+
+<p><h3><code>os.getenv (varname)</code></h3>
+
+<p>Returns the value of the process environment variable <code>varname</code>,
 or <B>nil</B> if the variable is not defined.
-<P>
-<h3> <TT>setlocale (locale [, category])</TT></h3><A NAME="setlocale"></A>
-<P>
-This function is an interface to the ANSI&nbsp;C function <CODE>setlocale</CODE>.
-<CODE>locale</CODE> is a string specifying a locale;
-<CODE>category</CODE> is an optional string describing which category to change:
-<CODE>"all"</CODE>, <CODE>"collate"</CODE>, <CODE>"ctype"</CODE>,
-<CODE>"monetary"</CODE>, <CODE>"numeric"</CODE>, or <CODE>"time"</CODE>;
-the default category is <CODE>"all"</CODE>.
+
+<p><h3><code>os.remove (filename)</code></h3>
+
+<p>Deletes the file with the given name.
+If this function fails, it returns <B>nil</B>,
+plus a string describing the error.
+
+<p><h3><code>os.rename (oldname, newname)</code></h3>
+
+<p>Renames file named <code>oldname</code> to <code>newname</code>.
+If this function fails, it returns <B>nil</B>,
+plus a string describing the error.
+
+<p><h3><code>os.setlocale (locale [, category])</code></h3>
+
+<p>Sets the current locale of the program.
+<code>locale</code> is a string specifying a locale;
+<code>category</code> is an optional string describing which category to change:
+<code>"all"</code>, <code>"collate"</code>, <code>"ctype"</code>,
+<code>"monetary"</code>, <code>"numeric"</code>, or <code>"time"</code>;
+the default category is <code>"all"</code>.
 The function returns the name of the new locale,
 or <B>nil</B> if the request cannot be honored.
-<P>
-<P>
-<A NAME="debugI"></A>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="7."></A>
-<H1>7 - The Debug Interface</H1> 
-<P>
-Lua has no built-in debugging facilities.
-Instead, it offers a special interface,
-by means of functions and <EM>hooks</EM>,
-which allows the construction of different
-kinds of debuggers, profilers, and other tools
-that need ``inside information'' from the interpreter.
-This interface is declared in <CODE>luadebug.h</CODE>.
-<P>
-<A NAME="7.1"></A>
-<H2>7.1 - Stack and Function Information</H2>
-<P>
-<A NAME="lua_getstack"></A>
-The main function to get information about the interpreter stack is
-<PRE>
-       int lua_getstack (lua_State *L, int level, lua_Debug *ar);
-</PRE>
-It fills parts of a <CODE>lua_Debug</CODE> structure with
-an identification of the <EM>activation record</EM>
-of the function executing at a given level.
-Level&nbsp;0 is the current running function,
-whereas level <I>n+1</I> is the function that has called level <I>n</I>.
-Usually, <CODE>lua_getstack</CODE> returns 1;
-when called with a level greater than the stack depth,
-it returns 0.
-<P>
-<A NAME="lua_Debug"></A>
-The structure <CODE>lua_Debug</CODE> is used to carry different pieces of
-information about an active function:
-<PRE>
-      typedef struct lua_Debug {
-        const char *event;     /* "call", "return" */
-        int currentline;       /* (l) */
-        const char *name;      /* (n) */
-        const char *namewhat;  /* (n) global, tag method, local, field */
-        int nups;              /* (u) number of upvalues */
-        int linedefined;       /* (S) */
-        const char *what;      /* (S) "Lua" function, "C" function, Lua "main" */
-        const char *source;    /* (S) */
-        char short_src[LUA_IDSIZE]; /* (S) */
-<P>
-        /* private part */
-        ...
-      } lua_Debug;
-</PRE>
-<CODE>lua_getstack</CODE> fills only the private part
-of this structure, for future use.
-To fill in the other fields of <CODE>lua_Debug</CODE> with useful information,
-call <A NAME="lua_getinfo"></A>
-<PRE>
-       int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
-</PRE>
-This function returns 0 on error
-(e.g., an invalid option in <CODE>what</CODE>).
-Each character in the string <CODE>what</CODE>
-selects some fields of <CODE>ar</CODE> to be filled,
-as indicated by the letter in parentheses in the definition of <CODE>lua_Debug</CODE>:
-`<CODE>S</CODE>' fills in the fields <CODE>source</CODE>, <CODE>linedefined</CODE>,
-and <CODE>what</CODE>;
-`<CODE>l</CODE>' fills in the field <CODE>currentline</CODE>, etc.
-Moreover, `<CODE>f</CODE>' pushes onto the stack the function that is
-running at the given level.
-<P>
-To get information about a function that is not active (that is,
-it is not in the stack),
-you push the function onto the stack,
-and start the <CODE>what</CODE> string with the character <CODE>&gt;</CODE>.
-For instance, to know in which line a function <CODE>f</CODE> was defined,
-you can write
-<PRE>
-       lua_Debug ar;
-       lua_getglobal(L, "f");
-       lua_getinfo(L, "&gt;S", &amp;ar);
-       printf("%d\n", ar.linedefined);
-</PRE>
-The fields of <CODE>lua_Debug</CODE> have the following meaning:
-<DL>
-<P>
-<DT><B>source</B><DD>
-If the function was defined in a string,
-<CODE>source</CODE> is that string;
-if the function was defined in a file,
-<CODE>source</CODE> starts with a <CODE>@</CODE> followed by the file name.
-<P>
-<DT><B>short_src</B><DD>
-A ``printable'' version of <CODE>source</CODE>, to be used in error messages.
-<P>
-<DT><B>linedefined</B><DD>
-the line number where the definition of the function starts.
-<P>
-<DT><B>what</B><DD> the string <CODE>"Lua"</CODE> if this is a Lua function,
-<CODE>"C"</CODE> if this is a C&nbsp;function,
-or <CODE>"main"</CODE> if this is the main part of a chunk.
-<P>
-<DT><B>currentline</B><DD>
-the current line where the given function is executing.
-When no line information is available,
-<CODE>currentline</CODE> is set to <I>-1</I>.
-<P>
-<DT><B>name</B><DD>
-a reasonable name for the given function.
-Because functions in Lua are first class values,
-they do not have a fixed name:
-Some functions may be the value of many global variables,
-while others may be stored only in a table field.
-The <CODE>lua_getinfo</CODE> function checks whether the given
-function is a tag method or the value of a global variable.
-If the given function is a tag method,
-then <CODE>name</CODE> points to the event name.
-If the given function is the value of a global variable,
-then <CODE>name</CODE> points to the variable name.
-If the given function is neither a tag method nor a global variable,
-then <CODE>name</CODE> is set to <CODE>NULL</CODE>.
-<P>
-<DT><B>namewhat</B><DD>
-Explains the previous field.
-If the function is a global variable,
-<CODE>namewhat</CODE> is <CODE>"global"</CODE>;
-if the function is a tag method,
-<CODE>namewhat</CODE> is <CODE>"tag-method"</CODE>;
-otherwise <CODE>namewhat</CODE> is <CODE>""</CODE> (the empty string).
-<P>
-<DT><B>nups</B><DD>
-Number of upvalues of a function.
-<P>
-</DL>
-<P>
-<P>
-<A NAME="7.2"></A>
-<H2>7.2 - Manipulating Local Variables</H2>
-<P>
-For the manipulation of local variables,
-<CODE>luadebug.h</CODE> uses indices:
-The first parameter or local variable has index&nbsp;1, and so on,
-until the last active local variable.
-<P>
-<A NAME="lua_getlocal"></A><A NAME="lua_setlocal"></A>
-The following functions allow the manipulation of the
-local variables of a given activation record.
-<PRE>
-       const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);
-       const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);
-</PRE>
-The parameter <CODE>ar</CODE> must be a valid activation record,
-filled by a previous call to <CODE>lua_getstack</CODE> or
-given as argument to a hook (see Section&nbsp;<A HREF="#sub-hooks">7.3</A>).
-Function <CODE>lua_getlocal</CODE> gets the index of a local variable
-(<CODE>n</CODE>), pushes its value onto the stack,
-and returns its name.
-For <CODE>lua_setlocal</CODE>,
-you push the new value onto the stack,
-and the function assigns that value to the variable and returns its name.
-Both functions return <CODE>NULL</CODE> on failure;
-that happens if the index is greater than
-the number of active local variables.
-<P>
-As an example, the following function lists the names of all
-local variables for a function at a given level of the stack:
-<PRE>
-       int listvars (lua_State *L, int level) {
-         lua_Debug ar;
-         int i = 1;
-         const char *name;
-         if (lua_getstack(L, level, &amp;ar) == 0)
-           return 0;  /* failure: no such level in the stack */
-         while ((name = lua_getlocal(L, &amp;ar, i++)) != NULL) {
-           printf("%s\n", name);
-           lua_pop(L, 1);  /* remove variable value */
-         }
-         return 1;
-       }
-</PRE>
-<P>
-<P>
-<A NAME="sub-hooks"></A>
-<A NAME="7.3"></A>
-<H2>7.3 - Hooks</H2>
-<P>
-The Lua interpreter offers two hooks for debugging purposes:
-a <EM>call</EM> hook and a <EM>line</EM> hook.
-Both have the same type,
-<A NAME="lua_Hook"></A>
-<PRE>
-       typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
-</PRE>
-and you can set them with the following functions:
-<A NAME="lua_setcallhook"></A><A NAME="lua_setlinehook"></A>
-<PRE>
-       lua_Hook lua_setcallhook (lua_State *L, lua_Hook func);
-       lua_Hook lua_setlinehook (lua_State *L, lua_Hook func);
-</PRE>
-A hook is disabled when its value is <CODE>NULL</CODE>,
-which is the initial value of both hooks.
-The functions <CODE>lua_setcallhook</CODE> and <CODE>lua_setlinehook</CODE>
-set their corresponding hooks and return their previous values.
-<P>
-The call hook is called whenever the
-interpreter enters or leaves a function.
-The <CODE>event</CODE> field of <CODE>ar</CODE> has the strings <CODE>"call"</CODE>
-or <CODE>"return"</CODE>.
-This <CODE>ar</CODE> can then be used in calls to <CODE>lua_getinfo</CODE>,
-<CODE>lua_getlocal</CODE>, and <CODE>lua_setlocal</CODE>
-to get more information about the function and to manipulate its
-local variables.
-<P>
-The line hook is called every time the interpreter changes
-the line of code it is executing.
-The <CODE>event</CODE> field of <CODE>ar</CODE> has the string <CODE>"line"</CODE>,
-and the <CODE>currentline</CODE> field has the line number.
-Again, you can use this <CODE>ar</CODE> in other calls to the debug API.
-<P>
-While Lua is running a hook, it disables other calls to hooks.
-Therefore, if a hook calls Lua to execute a function or a chunk,
-this execution ocurrs without any calls to hooks.
-<P>
-<P>
-<A NAME="7.4"></A>
-<H2>7.4 - The Reflexive Debug Interface</H2>
-<P>
-The library <CODE>ldblib</CODE> provides
+
+<p><h3><code>os.time ([table])</code></h3>
+
+<p>Returns the current time when called without arguments,
+or a time representing the date and time specified by the given table.
+This table must have fields <code>year</code>, <code>month</code>, and <code>day</code>,
+and may have fields <code>hour</code>, <code>min</code>, <code>sec</code>, and <code>isdst</code>
+(for a description of these fields, see the <code>os.date</code> function).
+
+<p>The returned value is a number, whose meaning depends on your system.
+In Posix, Windows, and some other systems, this number counts the number
+of seconds since some given start time (the "epoch").
+In other systems, the meaning is not specified,
+and the number returned by <code>time</code> can be used only as an argument to
+<code>date</code> and <code>difftime</code>.
+
+<p><h3><code>os.tmpname ()</code></h3>
+
+<p>Returns a string with a file name that can
+be used for a temporary file.
+The file must be explicitly opened before its use
+and removed when no longer needed.
+
+<p>This function is equivalent to the <code>tmpnam</code> C&nbsp;function,
+and many people (and even some compilers!) advise against its use,
+because between the time you call this function
+and the time you open the file,
+it is possible for another process
+to create a file with the same name.
+
+<p><h2>5.8 - The Reflexive Debug Interface</h2>
+
+<p>The <code>debug</code> library provides
 the functionality of the debug interface to Lua programs.
-If you want to use this library,
-your host application must open it,
-by calling <CODE>lua_dblibopen</CODE>.
-<A NAME="lua_dblibopen"></A>
-<P>
-You should exert great care when using this library.
+You should exert care when using this library.
 The functions provided here should be used exclusively for debugging
-and similar tasks (e.g., profiling).
+and similar tasks, such as profiling.
 Please resist the temptation to use them as a
-usual programming tool.
-They are slow and violate some (otherwise) secure aspects of the
-language (e.g., privacy of local variables).
-As a general rule, if your program does not need this library,
-do not open it.
-<P>
-<P>
-<h3> <TT>getinfo (function, [what])</TT></h3><A NAME="getinfo"></A>
-<P>
-This function returns a table with information about a function.
+usual programming tool:
+They can be very slow.
+Moreover, <code>setlocal</code> and <code>getlocal</code>
+violate the privacy of local variables
+and therefore can compromise some otherwise secure code.
+
+<p>All functions in this library are provided
+inside a <code>debug</code> table.
+
+<p><h3><code>debug.debug ()</code></h3>
+
+<p>Enters an interactive mode with the user,
+running each string that the user enters.
+Using simple commands and other debug facilities,
+the user can inspect global and local variables,
+change their values, evaluate expressions, and so on.
+A line containing only the word <code>cont</code> finishes this function,
+so that the caller continues its execution.
+
+<p>Note that commands for <code>debug.debug</code> are not lexically nested
+with any function, so they have no direct access to local variables.
+
+<p><h3><code>debug.gethook ()</code></h3>
+
+<p>Returns the current hook settings, as three values:
+the current hook function, the current hook mask,
+and the current hook count (as set by the <code>debug.sethook</code> function).
+
+<p><h3><code>debug.getinfo (function [, what])</code></h3>
+
+<p>This function returns a table with information about a function.
 You can give the function directly,
-or you can give a number as the value of <CODE>function</CODE>,
-which means the function running at level <CODE>function</CODE> of the stack:
-Level 0 is the current function (<CODE>getinfo</CODE> itself);
-level 1 is the function that called <CODE>getinfo</CODE>;
+or you can give a number as the value of <code>function</code>,
+which means the function running at level <code>function</code> of the call stack:
+Level 0 is the current function (<code>getinfo</code> itself);
+level 1 is the function that called <code>getinfo</code>;
 and so on.
-If <CODE>function</CODE> is a number larger than the number of active functions,
-then <CODE>getinfo</CODE> returns <B>nil</B>.
-<P>
-The returned table contains all the fields returned by <CODE>lua_getinfo</CODE>,
-with the string <CODE>what</CODE> describing what to get.
-The default for <CODE>what</CODE> is to get all information available.
-<P>
-For instance, the expression <CODE>getinfo(1,"n").name</CODE> returns
+If <code>function</code> is a number larger than the number of active functions,
+then <code>getinfo</code> returns <B>nil</B>.
+
+<p>The returned table contains all the fields returned by <code>lua_getinfo</code>,
+with the string <code>what</code> describing which fields to fill in.
+The default for <code>what</code> is to get all information available.
+If present,
+the option `<code>f</code>&acute;
+adds a field named <code>func</code> with the function itself.
+
+<p>For instance, the expression <code>debug.getinfo(1,"n").name</code> returns
 the name of the current function, if a reasonable name can be found,
-and <CODE>getinfo(print)</CODE> returns a table with all available information
-about the <CODE>print</CODE> function.
-<P>
-<P>
-<h3> <TT>getlocal (level, local)</TT></h3><A NAME="getlocal"></A>
-<P>
-This function returns the name and the value of the local variable
-with index <CODE>local</CODE> of the function at level <CODE>level</CODE> of the stack.
+and <code>debug.getinfo(print)</code> returns a table with all available information
+about the <code>print</code> function.
+
+<p><h3><code>debug.getlocal (level, local)</code></h3>
+
+<p>This function returns the name and the value of the local variable
+with index <code>local</code> of the function at level <code>level</code> of the stack.
 (The first parameter or local variable has index&nbsp;1, and so on,
 until the last active local variable.)
 The function returns <B>nil</B> if there is no local
 variable with the given index,
-and raises an error when called with a <CODE>level</CODE> out of range.
-(You can call <CODE>getinfo</CODE> to check whether the level is valid.)
-<P>
-<h3> <TT>setlocal (level, local, value)</TT></h3><A NAME="setlocal"></A>
-<P>
-This function assigns the value <CODE>value</CODE> to the local variable
-with index <CODE>local</CODE> of the function at level <CODE>level</CODE> of the stack.
+and raises an error when called with a <code>level</code> out of range.
+(You can call <code>debug.getinfo</code> to check whether the level is valid.)
+
+<p><h3><code>debug.getupvalue (func, up)</code></h3>
+
+<p>This function returns the name and the value of the upvalue
+with index <code>up</code> of the function <code>func</code>.
+The function returns <B>nil</B> if there is no upvalue with the given index.
+
+<p><h3><code>debug.setlocal (level, local, value)</code></h3>
+
+<p>This function assigns the value <code>value</code> to the local variable
+with index <code>local</code> of the function at level <code>level</code> of the stack.
 The function returns <B>nil</B> if there is no local
 variable with the given index,
-and raises an error when called with a <CODE>level</CODE> out of range.
-<P>
-<h3> <TT>setcallhook (hook)</TT></h3><A NAME="setcallhook"></A>
-<P>
-Sets the function <CODE>hook</CODE> as the call hook;
-this hook will be called every time the interpreter starts and
-exits the execution of a function.
-The only argument to the call hook is the event name (<CODE>"call"</CODE> or
-<CODE>"return"</CODE>).
-You can call <CODE>getinfo</CODE> with level 2 to get more information about
-the function being called or returning
-(level&nbsp;0 is the <CODE>getinfo</CODE> function,
-and level&nbsp;1 is the hook function).
-When called without arguments,
-this function turns off call hooks.
-<CODE>setcallhook</CODE> returns the old hook.
-<P>
-<h3> <TT>setlinehook (hook)</TT></h3><A NAME="setlinehook"></A>
-<P>
-Sets the function <CODE>hook</CODE> as the line hook;
-this hook will be called every time the interpreter changes
-the line of code it is executing.
-The only argument to the line hook is the line number the interpreter
-is about to execute.
-When called without arguments,
-this function turns off line hooks.
-<CODE>setlinehook</CODE> returns the old hook.
-<P>
-<P>
-<A NAME="lua-sa"></A>
-<!-- ====================================================================== -->
-<HR>
-<A NAME="8."></A>
-<H1>8 - Lua Stand-alone</H1> 
-<P>
-Although Lua has been designed as an extension language,
+and raises an error when called with a <code>level</code> out of range.
+(You can call <code>getinfo</code> to check whether the level is valid.)
+
+<p><h3><code>debug.setupvalue (func, up, value)</code></h3>
+
+<p>This function assigns the value <code>value</code> to the upvalue
+with index <code>up</code> of the function <code>func</code>.
+The function returns <B>nil</B> if there is no upvalue
+with the given index.
+
+<p><h3><code>debug.sethook (hook, mask [, count])</code></h3>
+
+
+<p>Sets the given function as a hook.
+The string <code>mask</code> and the number <code>count</code> describe
+when the hook will be called.
+The string mask may have the following characters,
+with the given meaning:
+<ul>
+<li><b><code>"c"</code></b> The hook is called every time Lua calls a function;
+<li><b><code>"r"</code></b> The hook is called every time Lua returns from a function;
+<li><b><code>"l"</code></b> The hook is called every time Lua enters a new line of code.
+</ul>
+With a <code>count</code> different from zero,
+the hook is called after every <code>count</code> instructions.
+
+<p>When called without arguments,
+the <code>debug.sethook</code> function turns off the hook.
+
+<p>When the hook is called, its first parameter is always a string
+describing the event that triggered its call:
+<code>"call"</code>, <code>"return"</code> (or <code>"tail return"</code>),
+<code>"line"</code>, and <code>"count"</code>.
+Moreover, for line events,
+it also gets as its second parameter the new line number.
+Inside a hook,
+you can call <code>getinfo</code> with level 2 to get more information about
+the running function
+(level&nbsp;0 is the <code>getinfo</code> function,
+and level&nbsp;1 is the hook function),
+unless the event is <code>"tail return"</code>.
+In this case, Lua is only simulating the return,
+and a call to <code>getinfo</code> will return invalid data.
+
+<p><h3><code>debug.traceback ([message])</code></h3>
+
+<p>Returns a string with a traceback of the call stack.
+An optional <code>message</code> string is appended
+at the beginning of the traceback. 
+This function is typically used with <code>xpcall</code> to produce
+better error messages.
+
+<p>
+<a name="lua-sa"><h1>6 - Lua Stand-alone</h1></a>
+
+<p>Although Lua has been designed as an extension language,
 to be embedded in a host C&nbsp;program,
-it is frequently used as a stand-alone language.
+it is also frequently used as a stand-alone language.
 An interpreter for Lua as a stand-alone language,
-called simply <CODE>lua</CODE>,
+called simply <code>lua</code>,
 is provided with the standard distribution.
-This program can be called with any sequence of the following arguments:
-<DL>
-<DT><B><TT>-sNUM</TT></B><DD> sets the stack size to <TT>NUM</TT>
-(if present, this must be the first option);
-<DT><B><TT>-</TT> </B><DD> executes <CODE>stdin</CODE> as a file;
-<DT><B><TT>-c</TT></B><DD> calls <CODE>lua_close</CODE> after running all arguments;
-<DT><B><TT>-e</TT> \rm<EM>stat</EM></B><DD> executes string <CODE>stat</CODE>;
-<DT><B><TT>-f filename</TT></B><DD> executes file <CODE>filename</CODE> with the
-remaining arguments in table <CODE>arg</CODE>;
-<DT><B><TT>-i</TT></B><DD> enters interactive mode with prompt;
-<DT><B><TT>-q</TT></B><DD> enters interactive mode without prompt;
-<DT><B><TT>-v</TT></B><DD> prints version information;
-<DT><B><TT>var=value</TT></B><DD> sets global <CODE>var</CODE> to string <CODE>"value"</CODE>;
-<DT><B><TT>filename</TT></B><DD> executes file <CODE>filename</CODE>.
-</DL>
+The stand-alone interpreter includes
+all standard libraries plus the reflexive debug interface.
+Its usage is:
+<PRE>
+      lua [options] [script [args]]
+</PRE>
+The options are:
+<ul>
+<li><b><code>-</code> </b> executes <code>stdin</code> as a file;
+<li><b><code>-e</code> <em>stat</em></b> executes string <em>stat</em>;
+<li><b><code>-l</code> <em>file</em></b> "requires" <em>file</em>;
+<li><b><code>-i</code></b> enters interactive mode after running <em>script</em>;
+<li><b><code>-v</code></b> prints version information;
+<li><b><code>--</code></b> stop handling options.
+</ul>
+After handling its options, <code>lua</code> runs the given <em>script</em>,
+passing to it the given <em>args</em>.
 When called without arguments,
-<CODE>lua</CODE> behaves as <CODE>lua -v -i</CODE> when <CODE>stdin</CODE> is a terminal,
-and as <CODE>lua -</CODE> otherwise.
-<P>
-All arguments are handled in order, except <CODE>-c</CODE>.
+<code>lua</code> behaves as <code>lua -v -i</code> when <code>stdin</code> is a terminal,
+and as <code>lua -</code> otherwise.
+
+<p>Before running any argument,
+the interpreter checks for an environment variable <code>LUA_INIT</code>.
+If its format is @<em>filename</em>,
+then lua executes the file.
+Otherwise, lua executes the string itself.
+
+<p>All options are handled in order, except <code>-i</code>.
 For instance, an invocation like
 <PRE>
-       $ lua -i a=test prog.lua
-</PRE>
-will first interact with the user until an <CODE>EOF</CODE> in <CODE>stdin</CODE>,
-then will set <CODE>a</CODE> to <CODE>"test"</CODE>,
-and finally will run the file <CODE>prog.lua</CODE>.
-(Here,
-<CODE>$</CODE> is the shell prompt. Your prompt may be different.)
-<P>
-When the option <TT>-f filename</TT> is used,
-all remaining arguments in the command line
-are passed to the Lua program <CODE>filename</CODE> in a table called <CODE>arg</CODE>.
-In this table,
-the field <CODE>n</CODE> gets the index of the last argument,
-and the field 0 gets <CODE>"filename"</CODE>.
+       $ lua -e'a=1' -e 'print(a)' script.lua
+</PRE>
+will first set <code>a</code> to 1, then print <code>a</code>,
+and finally run the file <code>script.lua</code>.
+(Here, <code>$</code> is the shell prompt. Your prompt may be different.)
+
+<p>Before starting to run the script,
+<code>lua</code> collects all arguments in the command line
+in a global table called <code>arg</code>.
+The script name is stored in index 0,
+the first argument after the script name goes to index 1,
+and so on.
+The field <code>n</code> gets the number of arguments after the script name.
+Any arguments before the script name
+(that is, the interpreter name plus the options)
+go to negative indices.
 For instance, in the call
 <PRE>
-       $ lua a.lua -f b.lua t1 t3
+       $ lua -la.lua b.lua t1 t2
 </PRE>
-the interpreter first runs the file <TT>a.lua</TT>,
+the interpreter first runs the file <code>a.lua</code>,
 then creates a table
 <PRE>
-       arg = {"t1", "t3";  n = 2, [0] = "b.lua"}
+       arg = { [-2] = "lua", [-1] = "-la.lua", [0] = "b.lua",
+               [1] = "t1", [2] = "t2"; n = 2 }
 </PRE>
-and finally runs the file <TT>b.lua</TT>.
-<A NAME="getargs"></A>
-The stand-alone interpreter also provides a <CODE>getargs</CODE> function that
-can be used to access <EM>all</EM> command line arguments.
-For instance, if you call Lua with the line
+and finally runs the file <code>b.lua</code>.
+
+<p>In interactive mode,
+if you write an incomplete statement,
+the interpreter waits for its completion.
+
+<p>If the global variable <code>_PROMPT</code> is defined as a string,
+then its value is used as the prompt.
+Therefore, the prompt can be changed directly on the command line:
 <PRE>
-       $ lua -c a b
+       $ lua -e"_PROMPT='myprompt> '" -i
 </PRE>
-then a call to <CODE>getargs</CODE> in <CODE>a</CODE> or <CODE>b</CODE> will return the table
+(the outer pair of quotes is for the shell,
+the inner is for Lua),
+or in any Lua programs by assigning to <code>_PROMPT</code>.
+Note the use of <code>-i</code> to enter interactive mode; otherwise,
+the program would end just after the assignment to <code>_PROMPT</code>.
+
+<p>In Unix systems, Lua scripts can be made into executable programs
+by using <code>chmod +x</code> and the&nbsp;<code>#!</code> form,
+as in
 <PRE>
-       {[0] = "lua", [1] = "-c", [2] = "a", [3] = "b", n = 3}
+#!/usr/local/bin/lua
 </PRE>
-<P>
-In interactive mode,
-a multi-line statement can be written finishing intermediate
-lines with a backslash (`<CODE>\</CODE>').
-If the global variable <A NAME="_PROMPT"><TT>_PROMPT</TT></A> is defined as a string,
-then its value is used as the prompt.
-Therefore, the prompt can be changed directly on the command line:
+(Of course,
+the location of the Lua interpreter may be different in your machine.
+If <code>lua</code> is in your <code>PATH</code>,
+then 
 <PRE>
-       $ lua _PROMPT='myprompt&gt; ' -i
-</PRE>
-or in any Lua programs by assigning to <CODE>_PROMPT</CODE>.
-<P>
-In Unix systems, Lua scripts can be made into executable programs
-by using <CODE>chmod +x</CODE> and the&nbsp;<CODE>#!</CODE> form,
-as in <CODE>#!/usr/local/bin/lua</CODE>,
-or <CODE>#!/usr/local/bin/lua -f</CODE> to get other arguments.
-<P>
-<P>
-<HR>
-<A NAME="Acknowledgments"></A>
+#!/usr/bin/env lua
+</PRE>
+is a more portable solution.) 
+
+<p>
 <h1>Acknowledgments</h1>
-<P>
-The authors would like to thank CENPES/PETROBRAS which,
-jointly with TeCGraf, used early versions of
-this system extensively and gave valuable comments.
-The authors would also like to thank Carlos Henrique Levy,
-who found the name of the game.
-Lua means ``moon'' in Portuguese.
-<P>
-<P>
-<P>
-<HR>
-<A NAME="Incompatibilities"></A>
-<h1>Incompatibilities with Previous Versions</h1>
-<P>
-Lua 4.0 is a major revision of the language.
-We took a great care to avoid incompatibilities with
-the previous public versions of Lua,
-but some differences had to be introduced.
-Here is a list of all these incompatibilities.
-<P>
-<P>
-<h2>Incompatibilities with <A NAME="version 3.2</h2>">version 3.2</h2></A>
-<P>
-<h3>Changes in the Language</h3>
-<UL>
-<P>
-<LI>
-All pragmas (<CODE>$debug</CODE>, <CODE>$if</CODE>, ...) have been removed.
-<P>
-<LI>
-<B>for</B>, <B>break</B>, and <B>in</B> are now reserved words.
-<P>
-<LI>
-Garbage-collection tag methods for tables is now obsolete.
-<P>
-<LI>
-There is now only one tag method for order operators.
-<P>
-<LI>
-In nested function calls like <CODE>f(g(x))</CODE>,
-<EM>all</EM> return values from <CODE>g</CODE> are passed as arguments to <CODE>f</CODE>.
-This only happens when <CODE>g</CODE> is the last
-or the only argument to <CODE>f</CODE>.
-<P>
-<LI>
-The pre-compiler may assume that some operators are associative,
-for optimizations.
-This may cause problems if these operators
-have non-associative tag methods.
-<P>
-<LI>Old pre-compiled code is obsolete, and must be re-compiled.
-<P>
-</UL>
-<P>
-<P>
-<h3>Changes in the Libraries</h3>
-<UL>
-<P>
-<LI>
-When traversing a table with <CODE>next</CODE> or <CODE>foreach</CODE>,
-the table cannot be modified in any way.
-<P>
-<LI>
-General read patterns are now obsolete.
-<P>
-<LI>
-The functions <CODE>rawgettable</CODE> and <CODE>rawsettable</CODE>
-have been renamed to <CODE>rawget</CODE> and <CODE>rawset</CODE>.
-<P>
-<LI>
-The functions <CODE>foreachvar</CODE>, <CODE>nextvar</CODE>,
-<CODE>rawsetglobal</CODE>, and <CODE>rawgetglobal</CODE> are obsolete.
-You can get their functionality using table operations
-over the table of globals,
-which is returned by <CODE>globals</CODE>.
-<P>
-<LI>
-<CODE>setglobal</CODE> and <CODE>sort</CODE> no longer return a value;
-<CODE>type</CODE> no longer returns a second value.
-<P>
-<LI>
-The <CODE>p</CODE> option in function <CODE>call</CODE> is now obsolete.
-<P>
-</UL>
-<P>
-<P>
-<h3>Changes in the API</h3>
-<UL>
-<P>
-<LI>
-The API has been completely rewritten:
-It is now fully reentrant and much clearer.
-<P>
-<LI>
-The debug API has been completely rewritten.
-<P>
-</UL>
-<P>
-<A NAME="BNF"></A>
-<A NAME="grammar"></A>
-<HR>
-<h1>The Complete Syntax of Lua</h1> 
-<P>
-<A NAME="grammar"></A>
-<P>
-<PRE>
-<P>
-       chunk ::= {stat [`<B>;</B>']}
-<P>
-       block ::= chunk
-<P>
-       stat ::=  varlist1 `<B>=</B>' explist1 <BR>	| functioncall <BR>	| <B>do</B> block <B>end</B> <BR>	| <B>while</B> exp1 <B>do</B> block <B>end</B> <BR>	| <B>repeat</B> block <B>until</B> exp1 <BR>	| <B>if</B> exp1 <B>then</B> block {<B>elseif</B> exp1 <B>then</B> block} [<B>else</B> block] <B>end</B> <BR>	| <B>return</B> [explist1] <BR>	| <B>break</B> <BR>	| <B>for</B> `<B>name</B>' `<B>=</B>' exp1 `<B>,</B>' exp1 [`<B>,</B>' exp1] <B>do</B> block <B>end</B> <BR>	| <B>for</B> `<B>name</B>' `<B>,</B>' `<B>name</B>' <B>in</B> exp1 <B>do</B> block <B>end</B> <BR>	| <B>function</B> funcname `<B>(</B>' [parlist1] `<B>)</B>' block <B>end</B> <BR>	| <B>local</B> declist [init] 
-<P>
-       funcname ::=  `<B>name</B>' | `<B>name</B>' `<B>.</B>' `<B>name</B>' | `<B>name</B>' `<B>:</B>' `<B>name</B>' 
-<P>
-       varlist1 ::= var {`<B>,</B>' var}
-<P>
-       var ::=  `<B>name</B>' | varorfunc `<B>[</B>' exp1 `<B>]</B>' | varorfunc `<B>.</B>' `<B>name</B>' 
-<P>
-       varorfunc ::= var | functioncall
-<P>
-       declist ::= `<B>name</B>' {`<B>,</B>' `<B>name</B>'}
-<P>
-       init ::= `<B>=</B>' explist1
-<P>
-       explist1 ::= {exp1 `<B>,</B>'} exp
-<P>
-       exp1 ::= exp
-<P>
-       exp ::=  <B>nil</B> | `<B>number</B>' | `<B>literal</B>' | var | function | upvalue <BR>	| functioncall | tableconstructor | `<B>(</B>' exp `<B>)</B>' | exp binop exp | unop exp 
-<P>
-<P>
-       functioncall ::=  varorfunc args | varorfunc `<B>:</B>' `<B>name</B>' args 
-<P>
-       args ::=  `<B>(</B>' [explist1] `<B>)</B>' | tableconstructor | `<B>literal</B>' 
-<P>
-       function ::= <B>function</B> `<B>(</B>' [parlist1] `<B>)</B>' block <B>end</B>
-<P>
-       parlist1 ::=  `<B>...</B>' | `<B>name</B>' {`<B>,</B>' `<B>name</B>'} [`<B>,</B>' `<B>...</B>'] 
-<P>
-       upvalue ::= `<B>%</B>' `<B>name</B>'
-<P>
-       tableconstructor ::= `<B>{</B>' fieldlist `<B>}</B>'
-       fieldlist ::=  lfieldlist | ffieldlist | lfieldlist `<B>;</B>' ffieldlist | ffieldlist `<B>;</B>' lfieldlist 
-       lfieldlist ::= [lfieldlist1]
-       ffieldlist ::= [ffieldlist1]
-       lfieldlist1 ::= exp {`<B>,</B>' exp} [`<B>,</B>']
-       ffieldlist1 ::= ffield {`<B>,</B>' ffield} [`<B>,</B>']
-       ffield ::=  `<B>[</B>' exp `<B>]</B>' `<B>=</B>' exp | `<B>name</B>' `<B>=</B>' exp 
-<P>
-       binop ::= `<B>+</B>' | `<B>-</B>' | `<B>*</B>' | `<B>/</B>' | `<B>\^{ </B>' | `<B>..</B>' <BR>	| `<B>&lt;</B>' | `<B>&lt;=</B>' | `<B>&gt;</B>' | `<B>&gt;=</B>' | `<B>==</B>' | `<B>\&nbsp;{ </B>'=} <BR>	| <B>and</B> | <B>or</B>}
-<P>
-       unop ::= `<B>-</B>' | <B>not</B>
-<P>
-</PRE>
-<P>
-
-<HR>
-<SMALL>
-Last update:
-Mon Nov  6 17:37:03 EDT 2000
-by <A HREF="http://www.tecgraf.puc-rio.br/~lhf/">lhf</A>.
-</SMALL>
-
-</BODY>
-</HTML>
+
+<p>The Lua team is grateful to <a href="http://www.tecgraf.puc-rio.br">Tecgraf</a> for its continued support to Lua.
+We thank everyone at <a href="http://www.tecgraf.puc-rio.br">Tecgraf</a>,
+specially the head of the group, Marcelo Gattass.
+At the risk of omitting several names,
+we also thank the following individuals for supporting,
+contributing to, and spreading the word about Lua:
+Alan Watson.
+Andr&#233; Clinio,
+Andr&#233; Costa,
+Antonio Scuri,
+Asko Kauppi,
+Bret Mogilefsky,
+Cameron Laird,
+Carlos Cassino,
+Carlos Henrique Levy,
+Claudio Terra,
+David Jeske,
+Ed Ferguson,
+Edgar Toernig,
+Erik Hougaard,
+Jim Mathies,
+John Belmonte,
+John Passaniti,
+John Roll,
+Jon Erickson,
+Jon Kleiser,
+Mark Ian Barlow,
+Nick Trout,
+Noemi Rodriguez,
+Norman Ramsey,
+Philippe Lhoste,
+Renata Ratton,
+Renato Borges,
+Renato Cerqueira,
+Reuben Thomas,
+Stephan Herrmann,
+Steve Dekorte,
+Thatcher Ulrich,
+Tom&#225;s Gorham,
+Vincent Penquerc'h,
+Thank you!
+
+<p><hr>
+
+<p><h1>Incompatibilities with Previous Versions</h1>
+
+
+<p>Lua 5.0 is a major release.
+There are several incompatibilities with its previous version, Lua 4.0.
+
+<p><h2>Incompatibilities with version 4.0</h2>
+
+<p><h3>Changes in the Language</h3>
+<ul>
+
+<p><li>
+The whole tag-method scheme was replaced by metatables.
+
+<p><li> 
+Function calls written between parentheses result in exactly one value.
+
+<p><li> 
+A function call as the last expression in a list constructor
+(like <code>{a,b,f()}</code>) has all its return values inserted in the list.
+
+<p><li> 
+The precedence of <b>or</b> is smaller than the precedence of <b>and</b>.
+
+<p><li> 
+<b>in</b>, <b>false</b>, and <b>true</b> are reserved words.
+
+<p><li> 
+The old construction <code>for k,v in t</code>, where <code>t</code> is a table,
+is deprecated (although it is still supported).
+Use <code>for k,v in pairs(t)</code> instead.
+
+<p><li> 
+When a literal string of the form <code>[[...]]</code> starts with a newline,
+this newline is ignored.
+
+<p>
+
+<p><li> Upvalues in the form <code>%var</code> are obsolete;
+use external local variables instead.
+
+<p></ul>
+
+<p><h3>Changes in the Libraries</h3>
+<ul>
+
+<p><li> 
+Most library functions now are defined inside tables.
+There is a compatibility script (<code>compat.lua</code>) that
+redefine most of them as global names.
+
+<p><li> 
+In the math library, angles are expressed in radians.
+With the compatibility script (<code>compat.lua</code>),
+functions still work in degrees.
+
+<p><li> 
+The <code>call</code> function is deprecated.
+Use <code>f(unpack(tab))</code> instead of <code>call(f, tab)</code>
+for unprotected calls,
+or the new <code>pcall</code> function for protected calls.
+
+<p><li> 
+<code>dofile</code> do not handle errors, but simply propagates them.
+
+<p><li>
+<code>dostring</code> is deprecated. Use <code>loadstring</code> instead.
+
+<p><li> 
+The <code>read</code> option <code>*w</code> is obsolete.
+
+<p><li> 
+The <code>format</code> option <code>%n$</code> is obsolete.
+
+<p></ul>
+
+<p><h3>Changes in the API</h3>
+<ul>
+
+<p><li>
+<code>lua_open</code> does not have a stack size as its argument
+(stacks are dynamic).
+
+<p><li> 
+<code>lua_pushuserdata</code> is deprecated.
+Use <code>lua_newuserdata</code> or <code>lua_pushlightuserdata</code> instead.
+
+<p></ul>
+
+<p>
+
+<a name="BNF"><h1>The Complete Syntax of Lua</h1></a>
+
+
+<p>
+
+<p><pre>
+
+<p>	chunk ::= {stat [`<b>;</b>&acute;]}
+
+<p>	block ::= chunk
+
+<p>	stat ::=  varlist1 `<b>=</b>&acute; explist1 | functioncall | <b>do</b> block <b>end</b> | <b>while</b> exp <b>do</b> block <b>end</b> | <b>repeat</b> block <b>until</b> exp | <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> | <b>return</b> [explist1] | <b>break</b> | <b>for</b> Name `<b>=</b>&acute; exp `<b>,</b>&acute; exp [`<b>,</b>&acute; exp] <b>do</b> block <b>end</b> | <b>for</b> Name {`<b>,</b>&acute; Name} <b>in</b> explist1 <b>do</b> block <b>end</b> | <b>function</b> funcname funcbody | <b>local</b> <b>function</b> Name funcbody | <b>local</b> namelist [init] 
+
+<p>	funcname ::= Name {`<b>.</b>&acute; Name} [`<b>:</b>&acute; Name]
+
+<p>	varlist1 ::= var {`<b>,</b>&acute; var}
+
+<p>	var ::=  Name | prefixexp `<b>[</b>&acute; exp `<b>]</b>&acute; | prefixexp `<b>.</b>&acute; Name 
+
+<p>	namelist ::= Name {`<b>,</b>&acute; Name}
+
+<p>	init ::= `<b>=</b>&acute; explist1
+
+<p>	explist1 ::= {exp `<b>,</b>&acute;} exp
+
+<p>	exp ::=  <b>nil</b> <b>false</b> <b>true</b> | Number | Literal | function | prefixexp | tableconstructor | exp binop exp | unop exp 
+
+<p>	prefixexp ::= var | functioncall | `<b>(</b>&acute; exp `<b>)</b>&acute;
+
+<p>	functioncall ::=  prefixexp args | prefixexp `<b>:</b>&acute; Name args 
+
+<p>	args ::=  `<b>(</b>&acute; [explist1] `<b>)</b>&acute; | tableconstructor | Literal 
+
+<p>	function ::= <b>function</b> funcbody
+
+<p>	funcbody ::= `<b>(</b>&acute; [parlist1] `<b>)</b>&acute; block <b>end</b>
+
+<p>	parlist1 ::=  Name {`<b>,</b>&acute; Name} [`<b>,</b>&acute; `<b>...</b>&acute;] | `<b>...</b>&acute; 
+
+<p>	tableconstructor ::= `<b>{</b>&acute; [fieldlist] `<b>}</b>&acute;
+	fieldlist ::= field {fieldsep field} [fieldsep]
+	field ::= `<b>[</b>&acute; exp `<b>]</b>&acute; `<b>=</b>&acute; exp | name `<b>=</b>&acute; exp | exp
+	fieldsep ::= `<b>,</b>&acute; | `<b>;</b>&acute;
+
+<p>	binop ::= `<b>+</b>&acute; | `<b>-</b>&acute; | `<b>*</b>&acute; | `<b>/</b>&acute; | `<b>^</b>&acute; | `<b>..</b>&acute; | `<b>&#060;</b>&acute; | `<b>&#060;=</b>&acute; | `<b>></b>&acute; | `<b>>=</b>&acute; | `<b>==</b>&acute; | `<b>~=</b>&acute; | <b>and</b> | <b>or</b>
+
+<p>	unop ::= `<b>-</b>&acute; | <b>not</b>
+
+<p></pre>
+
+<p>
+
+<p>
+
+</body></html>
+
diff --git a/doc/readme.html b/doc/readme.html
index a574eccd..c50459d1 100644
--- a/doc/readme.html
+++ b/doc/readme.html
@@ -7,29 +7,28 @@
 
 <HR>
 <H1>
-<IMG SRC="logo.gif" ALT="Lua" ALIGN="bottom">
+<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua" BORDER=0></A>
 Documentation
 </H1>
 
 <UL>
-<LI><A HREF="http://www.tecgraf.puc-rio.br/lua/">Official web site</A>
-<LI><A HREF="index.html">Reference manual</A>
+<LI><A HREF="http://www.lua.org/">Official web site</A>
+<LI><A HREF="manual.html">Reference manual</A>
 <LI><A HREF="lua.html">lua man page</A>
 <LI><A HREF="luac.html">luac man page</A>
 <LI><A HREF="../README">lua/README</A>
+<LI><A HREF="../src/README">lua/src/README</A>
 <LI><A HREF="../src/lib/README">lua/src/lib/README</A>
 <LI><A HREF="../src/lua/README">lua/src/lua/README</A>
 <LI><A HREF="../src/luac/README">lua/src/luac/README</A>
 <LI><A HREF="../etc/README">lua/etc/README</A>
 <LI><A HREF="../test/README">lua/test/README</A>
-<LI><A HREF="../test/examples/www/README">lua/test/examples/www/README</A>
 </UL>
 
 <HR>
 <SMALL>
 Last update:
-Mon Nov  6 19:13:31 EDT 2000
-by <A HREF="http://www.tecgraf.puc-rio.br/~lhf/">lhf</A>.
+Tue Apr  1 14:35:18 EST 2003
 </SMALL>
 
 </BODY>
diff --git a/etc/.exrc b/etc/.exrc
new file mode 120000
index 00000000..d9067749
--- /dev/null
+++ b/etc/.exrc
@@ -0,0 +1 @@
+/home/n/lhf/lib/vi/c
\ No newline at end of file
diff --git a/etc/Makefile b/etc/Makefile
index a7768697..1286c640 100644
--- a/etc/Makefile
+++ b/etc/Makefile
@@ -1,16 +1,14 @@
-# makefile for etc
+# makefile for Lua etc
 
 LUA= ..
 
 include $(LUA)/config
 
 LIBLUA=$(LIB)/liblua.a
-ALL= bin2c min trace lua.def
+ALL= bin2c min trace noparser luab
 
-x:
-	@echo 'choose a target:' all $(ALL)
-
-all: $(ALL)
+all:
+	@echo 'choose a target:' $(ALL)
 
 bin2c:	bin2c.c
 	$(CC) $(CFLAGS) -o $@ $@.c
@@ -19,20 +17,26 @@ min:	min.c $(LIBLUA)
 	$(CC) $(CFLAGS) -o $@ $@.c -L$(LIB) -llua
 
 trace:	trace.c $(LIBLUA)
-	$(CC) $(CFLAGS) -o $@ $@.c -L$(LIB) -llua -llualib -lm
+	$(CC) -g $(CFLAGS) -o $@ $@.c -L$(LIB) -llua -llualib $(EXTRA_LIBS)
 
-def:	lua.def
+noparser: noparser.c
+	$(CC) $(CFLAGS) -I$(LUA)/src -o $@.o -c $@.c
 
-lua.def: $(INC)/lua.h
-	$(BIN)/lua def.lua < $(INC)/lua.h > $@
-	# cat $(INC)/l*.h | $(BIN)/lua def.lua > $@
+luab:	noparser $(LIBLUA)
+	cc -o $@ noparser.o $(LUA)/src/lua/lua.o -L$(LIB) -llua -llualib $(EXTRA_LIBS)
+	$(BIN)/luac $(LUA)/test/hello.lua
+	$@ luac.out
+	-$@ -e'a=1'
 
-stdcall:
-	mkdir -p Stdcall
-	grep -l _API $(LUA)/src/*.[ch] $(LUA)/src/*/*.[ch] | xargs -n1 -i echo $(BIN)/lua stdcall.lua '<{}' '>Stdcall/{}'
+flat:
+	cd ..; mkdir flat; mv include/*.h src/*.[ch] src/*/*.[ch] flat
 
 $(LIBLUA):
 	cd ../src; $(MAKE)
 
 clean:
-	rm -f $(ALL)
+	rm -f $(ALL) a.out core *.o luac.out
+
+luser_tests.h: RCS/ltests.h,v
+	co -q -M ltests.h
+	mv -f ltests.h $@
diff --git a/etc/README b/etc/README
index eaae1c3d..c838a7fe 100644
--- a/etc/README
+++ b/etc/README
@@ -1,43 +1,54 @@
-This directory contains some code that might be useful.
+This directory contains some useful files and code.
+Unlike the code in ../src, everything here is in the public domain.
 
 bin2c.c
-	This program converts files to byte arrays that are automatically
-	run with lua_dobuffer. This allows C programs to include all necessary
-	Lua code, even in precompiled form. Even if the code is included in
-	source form, bin2c is useful because it avoids the hassle of having to
-	quote special characters in C strings.
-	Example of usage: Run bin2c file1 file2 ... > init.h. Then, in your C
-	program, just do #include "init.h" anywhere in the *body* of a
+	This program converts files to byte arrays that are automatically run
+	with lua_dobuffer. This allows C programs to include all necessary Lua
+	code, even in precompiled form. Even if the code is included in source
+	form, bin2c is useful because it avoids the hassle of having to quote
+	special characters in C strings.
+	Example of usage: Run bin2c file1 file2 ... > init.h. Then, in your
+	C program, just do #include "init.h" anywhere in the *body* of a
 	function. This will be equivalent to calling
 		lua_dofile(L,"file1"); lua_dofile(L,"file2"); ...
 	Note that the Lua state is called "L". If you use a different name,
-	say "mystate", just #define L mystate before #include "init.h".
+	say "mystate", just #define L mystate before you #include "init.h".
 
-def.lua
-	A Lua script for creating .DEF for Windows DLLs.
-	Just do "make def" to create lua.def.
+compat.lua
+	A compatibility module for Lua 4.0 functions.
 
-min.c
-	A minimal Lua interpreter.
+doall.lua
+	Emulate the command line behaviour of Lua 4.0
 
 lua.ico
 	A Lua icon for Windows.
-	It was drawn by hand by Markus Gritsch <gritsch@iue.tuwien.ac.at>.
+	Drawn by hand by Markus Gritsch <gritsch@iue.tuwien.ac.at>.
+
+lua.magic
+	Data for teaching file(1) about Lua precompiled chunks.
 
 lua.xpm
 	The same icon as lua.ico, but in XPM format.
 	It was converted with ImageMagick by Andy Tai <andy@exp.com>.
 
-lua.magic
-	Data for teaching file(1) about Lua precompiled chunks.
+luser_number.h
+	Number type configuration for Lua core.
+
+luser_tests.h
+	Self-test configuration for Lua core.
+
+min.c
+	A minimal Lua interpreter.
+	Good for learning and for starting your own.
 
-stdcall.lua
-	A Lua script for changing the calling convention to __stdcall.
-	Do "make stdcall" and new modules will be created in stdcall/.
+noparser.c
+	Linking with noparser.o avoids loading the parsing modules in lualib.a.
+	Do "make luab" to build a sample Lua intepreter that does not parse
+	Lua programs, only loads precompiled programs.
 
-setfallback.lua
-	A Lua implementation of fallbacks on top of tag methods.
-	You only need this module if you have Lua code that uses setfallback.
+saconfig.c
+	Configuration for Lua interpreter.
 
 trace.c
-	A simple execution tracer. An example of how to use the debugging hooks.
+	A simple execution tracer.
+	An example of how to use the debug hooks in C.
diff --git a/etc/bin2c.c b/etc/bin2c.c
index ac95a6e8..0993b16d 100644
--- a/etc/bin2c.c
+++ b/etc/bin2c.c
@@ -1,34 +1,30 @@
 /*
 * bin2c.c
-* convert binary files to byte arrays
+* convert files to byte arrays for automatic loading with lua_dobuffer
 * Luiz Henrique de Figueiredo (lhf@tecgraf.puc-rio.br)
-* 11 Sep 2000 22:37:14
+* 02 Apr 2003 20:44:31
 */
 
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-void dump(FILE* f, int n)
+static void dump(FILE* f, int n)
 {
- printf("static unsigned char B%d[]={\n",n);
+ printf("static const unsigned char B%d[]={\n",n);
  for (n=1;;n++)
  {
   int c=getc(f); 
   if (c==EOF) break;
-#if 0
-  printf("0x%02x,",c);
-#else
   printf("%3u,",c);
-#endif
   if (n==20) { putchar('\n'); n=0; }
  }
  printf("\n};\n\n");
 }
 
-void fdump(char* fn, int n)
+static void fdump(const char* fn, int n)
 {
- FILE* f= (fn==NULL) ? stdin : fopen(fn,"rb");	/* must open in binary mode */
+ FILE* f= fopen(fn,"rb");		/* must open in binary mode */
  if (f==NULL)
  {
   fprintf(stderr,"bin2c: cannot open ");
@@ -37,15 +33,15 @@ void fdump(char* fn, int n)
  }
  else
  {
-  if (fn!=NULL) printf("/* %s */\n",fn);
+  printf("/* %s */\n",fn);
   dump(f,n);
   fclose(f);
  }
 }
 
-void emit(char* fn, int n)
+static void emit(const char* fn, int n)
 {
- printf(" lua_dobuffer(L,B%d,sizeof(B%d),\"%s\");\n",n,n,fn);
+ printf(" lua_dobuffer(L,(const char*)B%d,sizeof(B%d),\"%s\");\n",n,n,fn);
 }
 
 int main(int argc, char* argv[])
@@ -55,7 +51,7 @@ int main(int argc, char* argv[])
  if (argc<2)
  {
   dump(stdin,0);
-  emit("(stdin)",0);
+  emit("=stdin",0);
  }
  else
  {
diff --git a/etc/compat.lua b/etc/compat.lua
new file mode 100644
index 00000000..2a7f3731
--- /dev/null
+++ b/etc/compat.lua
@@ -0,0 +1,192 @@
+-------------------------------------------------------------------
+-- Real globals
+-- _ALERT
+-- _ERRORMESSAGE
+-- _VERSION
+-- _G
+-- assert
+-- error
+-- metatable
+-- next
+-- print
+-- require
+-- tonumber
+-- tostring
+-- type
+-- unpack
+
+-------------------------------------------------------------------
+-- collectgarbage
+-- gcinfo
+
+-- globals
+
+-- call   -> protect(f, err)
+-- loadfile
+-- loadstring
+
+-- rawget
+-- rawset
+
+-- getargs = Main.getargs ??
+
+
+function do_ (f, err)
+  if not f then print(err); return end
+  local a,b = pcall(f)
+  if not a then print(b); return nil
+  else return b or true
+  end
+end
+
+function dostring(s) return do_(loadstring(s)) end
+-- function dofile(s) return do_(loadfile(s)) end
+
+-------------------------------------------------------------------
+-- Table library
+local tab = table
+foreach = tab.foreach
+foreachi = tab.foreachi
+getn = tab.getn
+tinsert = tab.insert
+tremove = tab.remove
+sort = tab.sort
+
+-------------------------------------------------------------------
+-- Debug library
+local dbg = debug
+getinfo = dbg.getinfo
+getlocal = dbg.getlocal
+setcallhook = function () error"`setcallhook' is deprecated" end
+setlinehook = function () error"`setlinehook' is deprecated" end
+setlocal = dbg.setlocal
+
+-------------------------------------------------------------------
+-- math library
+local math = math
+abs = math.abs
+acos = function (x) return math.deg(math.acos(x)) end
+asin = function (x) return math.deg(math.asin(x)) end
+atan = function (x) return math.deg(math.atan(x)) end
+atan2 = function (x,y) return math.deg(math.atan2(x,y)) end
+ceil = math.ceil
+cos = function (x) return math.cos(math.rad(x)) end
+deg = math.deg
+exp = math.exp
+floor = math.floor
+frexp = math.frexp
+ldexp = math.ldexp
+log = math.log
+log10 = math.log10
+max = math.max
+min = math.min
+mod = math.mod
+PI = math.pi
+--??? pow = math.pow  
+rad = math.rad
+random = math.random
+randomseed = math.randomseed
+sin = function (x) return math.sin(math.rad(x)) end
+sqrt = math.sqrt
+tan = function (x) return math.tan(math.rad(x)) end
+
+-------------------------------------------------------------------
+-- string library
+local str = string
+strbyte = str.byte
+strchar = str.char
+strfind = str.find
+format = str.format
+gsub = str.gsub
+strlen = str.len
+strlower = str.lower
+strrep = str.rep
+strsub = str.sub
+strupper = str.upper
+
+-------------------------------------------------------------------
+-- os library
+clock = os.clock
+date = os.date
+difftime = os.difftime
+execute = os.execute --?
+exit = os.exit
+getenv = os.getenv
+remove = os.remove
+rename = os.rename
+setlocale = os.setlocale
+time = os.time
+tmpname = os.tmpname
+
+-------------------------------------------------------------------
+-- compatibility only
+getglobal = function (n) return _G[n] end
+setglobal = function (n,v) _G[n] = v end
+
+-------------------------------------------------------------------
+
+local io, tab = io, table
+
+-- IO library (files)
+_STDIN = io.stdin
+_STDERR = io.stderr
+_STDOUT = io.stdout
+_INPUT = io.stdin
+_OUTPUT = io.stdout
+seek = io.stdin.seek   -- sick ;-)
+tmpfile = io.tmpfile
+closefile = io.close
+openfile = io.open
+
+function flush (f)
+  if f then f:flush()
+  else _OUTPUT:flush()
+  end
+end
+
+function readfrom (name)
+  if name == nil then
+    local f, err, cod = io.close(_INPUT)
+    _INPUT = io.stdin
+    return f, err, cod
+  else
+    local f, err, cod = io.open(name, "r")
+    _INPUT = f or _INPUT
+    return f, err, cod
+  end
+end
+
+function writeto (name)
+  if name == nil then
+    local f, err, cod = io.close(_OUTPUT)
+    _OUTPUT = io.stdout
+    return f, err, cod
+  else
+    local f, err, cod = io.open(name, "w")
+    _OUTPUT = f or _OUTPUT
+    return f, err, cod
+  end
+end
+
+function appendto (name)
+  local f, err, cod = io.open(name, "a")
+  _OUTPUT = f or _OUTPUT
+  return f, err, cod
+end
+
+function read (...)
+  local f = _INPUT
+  if type(arg[1]) == 'userdata' then
+    f = tab.remove(arg, 1)
+  end
+  return f:read(unpack(arg))
+end
+
+function write (...)
+  local f = _OUTPUT
+  if type(arg[1]) == 'userdata' then
+    f = tab.remove(arg, 1)
+  end
+  return f:write(unpack(arg))
+end
+
diff --git a/etc/def.lua b/etc/def.lua
deleted file mode 100644
index 736e32cd..00000000
--- a/etc/def.lua
+++ /dev/null
@@ -1,9 +0,0 @@
--- def.lua
--- make .DEF file from lua.h
--- usage: lua def.lua <lua.h >lua.def
-
-T=read"*a"
-write("LIBRARY LUA\nVERSION ")
-gsub(T,"LUA_VERSION.-(%d+%.%d+)",write)
-write("\nEXPORTS\n")
-gsub(T,"(lua_%w+)%s+%(",function (f) write("   ",f,"\n") end)
diff --git a/etc/doall.lua b/etc/doall.lua
new file mode 100644
index 00000000..fb0fad70
--- /dev/null
+++ b/etc/doall.lua
@@ -0,0 +1,6 @@
+-- emulate the command line behaviour of Lua 4.0
+-- usage: lua doall.lua f1.lua f2.lua f3.lua ...
+
+for i=1,table.getn(arg) do
+ dofile(arg[i])
+end
diff --git a/etc/lua.magic b/etc/lua.magic
index eb78f8d0..c7ae5955 100644
--- a/etc/lua.magic
+++ b/etc/lua.magic
@@ -1,10 +1,12 @@
 
-# Lua precompiled files
+# Lua precompiled files. Versions 2.3 and 4.1 were never officially released.
 0	string	\33Lua	precompiled chunk for Lua
->4	byte	0x23	2.3
+>4	byte	0x23	2.3*
 >4	byte	0x24	2.4
 >4	byte	0x25	2.5
 >4	byte	0x30	3.0
 >4	byte	0x31	3.1
 >4	byte	0x32	3.2
 >4	byte	0x40	4.0
+>4	byte	0x41	4.1*
+>4	byte	0x50	5.0
diff --git a/etc/luser_number.h b/etc/luser_number.h
new file mode 100644
index 00000000..8cc2678e
--- /dev/null
+++ b/etc/luser_number.h
@@ -0,0 +1,34 @@
+/* luser_number.h -- number type configuration for Lua core
+*
+* #define LUA_USER_H to this file and #define one of USE_* below
+*/
+
+#ifdef USE_DOUBLE
+#define LUA_NUMBER		double
+#define LUA_NUMBER_SCAN		"%lf"
+#define LUA_NUMBER_FMT		"%.14g"
+#endif
+
+#ifdef USE_FLOAT
+#define LUA_NUMBER		float
+#define LUA_NUMBER_SCAN		"%f"
+#define LUA_NUMBER_FMT		"%.5g"
+#endif
+
+#ifdef USE_LONG
+#define LUA_NUMBER		long
+#define LUA_NUMBER_SCAN		"%ld"
+#define LUA_NUMBER_FMT		"%ld"
+#define lua_str2number(s,p)     strtol((s), (p), 10)
+#endif
+
+#ifdef USE_INT
+#define LUA_NUMBER		int
+#define LUA_NUMBER_SCAN		"%d"
+#define LUA_NUMBER_FMT		"%d"
+#define lua_str2number(s,p)     ((int) strtol((s), (p), 10))
+#endif
+
+#ifdef USE_FASTROUND
+#define lua_number2int(i,d)	__asm__("fldl %1\nfistpl %0":"=m"(i):"m"(d))
+#endif
diff --git a/etc/luser_tests.h b/etc/luser_tests.h
new file mode 100644
index 00000000..1ee6e3fd
--- /dev/null
+++ b/etc/luser_tests.h
@@ -0,0 +1,68 @@
+/*
+** $Id: ltests.h,v 1.20 2002/12/04 17:29:05 roberto Exp $
+** Internal Header for Debugging of the Lua Implementation
+** See Copyright Notice in lua.h
+*/
+
+#ifndef ltests_h
+#define ltests_h
+
+
+#include <stdlib.h>
+
+
+#define LUA_DEBUG
+
+#define LUA_OPNAMES
+
+#undef NDEBUG
+#include <assert.h>
+#define lua_assert(c)           assert(c)
+#define check_exp(c,e)		(lua_assert(c), (e))
+#define api_check(L, o)		lua_assert(o)
+
+
+/* to avoid warnings, and to make sure value is really unused */
+#define UNUSED(x)       (x=0, (void)(x))
+
+
+/* memory allocator control variables */
+extern unsigned long memdebug_numblocks;
+extern unsigned long memdebug_total;
+extern unsigned long memdebug_maxmem;
+extern unsigned long memdebug_memlimit;
+
+
+#define l_realloc(b, os, s)	debug_realloc(b, os, s)
+#define l_free(b, os)		debug_realloc(b, os, 0)
+
+void *debug_realloc (void *block, size_t oldsize, size_t size);
+
+
+
+/* test for lock/unlock */
+extern int islocked;
+#define LUA_USERSTATE	int *
+#define getlock(l)	(*(cast(LUA_USERSTATE *, l) - 1))
+#define lua_userstateopen(l) if (l != NULL) getlock(l) = &islocked;
+#define lua_lock(l)     lua_assert((*getlock(l))++ == 0)
+#define lua_unlock(l)   lua_assert(--(*getlock(l)) == 0)
+
+
+int luaB_opentests (lua_State *L);
+
+#define LUA_EXTRALIBS { "tests", luaB_opentests },
+
+
+/* real main will be defined at `ltests.c' */
+int l_main (int argc, char *argv[]);
+#define main	l_main
+
+
+
+/* change some sizes to give some bugs a chance */
+
+#define LUAL_BUFFERSIZE		27
+#define MINSTRTABSIZE		2
+
+#endif
diff --git a/etc/min.c b/etc/min.c
index 0579ed3f..45731c9d 100644
--- a/etc/min.c
+++ b/etc/min.c
@@ -1,13 +1,12 @@
 /*
-* min.c
-* a minimal Lua interpreter. loads stdin only.
-* no standard library, only a "print" function.
+* min.c -- a minimal Lua interpreter
+* loads stdin only with minimal error handling.
+* no interaction, and no standard library, only a "print" function.
 */
 
 #include <stdio.h>
 #include "lua.h"
 
-/* a simple "print". based on the code in lbaselib.c */
 static int print(lua_State *L)
 {
  int n=lua_gettop(L);
@@ -17,6 +16,10 @@ static int print(lua_State *L)
   if (i>1) printf("\t");
   if (lua_isstring(L,i))
    printf("%s",lua_tostring(L,i));
+  else if (lua_isnil(L,i))
+   printf("%s","nil");
+  else if (lua_isboolean(L,i))
+   printf("%s",lua_toboolean(L,i) ? "true" : "false");
   else
    printf("%s:%p",lua_typename(L,lua_type(L,i)),lua_topointer(L,i));
  }
@@ -24,9 +27,20 @@ static int print(lua_State *L)
  return 0;
 }
 
+static const char *getF(lua_State *L, void *ud, size_t *size)
+{
+ FILE *f=(FILE *)ud;
+ static char buff[512];
+ if (feof(f)) return NULL;
+ *size=fread(buff,1,sizeof(buff),f);
+ return (*size>0) ? buff : NULL;
+}
+
 int main(void)
 {
- lua_State *L=lua_open(0);
+ lua_State *L=lua_open();
  lua_register(L,"print",print);
- return lua_dofile(L,NULL);
+ if (lua_load(L,getF,stdin,"=stdin") || lua_pcall(L,0,0,0))
+  fprintf(stderr,"%s\n",lua_tostring(L,-1));
+ return 0;
 }
diff --git a/etc/noparser.c b/etc/noparser.c
new file mode 100644
index 00000000..00c2b126
--- /dev/null
+++ b/etc/noparser.c
@@ -0,0 +1,26 @@
+/*
+* The code below can be used to make a Lua core that does not contain the
+* parsing modules (lcode, llex, lparser), which represent 35% of the total core.
+* You'll only be able to load binary files and strings, precompiled with luac.
+* (Of course, you'll have to build luac with the original parsing modules!)
+*
+* To use this module, simply compile it ("make noparser" does that) and
+* list its object file before the Lua libraries. The linker should then not
+* load the parsing modules. To try it, do "make luab".
+*/
+
+#include "llex.h"
+#include "lparser.h"
+#include "lzio.h"
+
+void luaX_init (lua_State *L) {
+  UNUSED(L);
+}
+
+Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff) {
+  UNUSED(z);
+  UNUSED(buff);
+  lua_pushstring(L,"parser not loaded");
+  lua_error(L);
+  return NULL;
+}
diff --git a/etc/saconfig.c b/etc/saconfig.c
new file mode 100644
index 00000000..bf3c64b7
--- /dev/null
+++ b/etc/saconfig.c
@@ -0,0 +1,87 @@
+/* sa-config.c -- configuration for stand-alone Lua interpreter
+*
+* #define LUA_USERCONFIG to this file
+*
+* Here are the features that can be customized using #define:
+*
+*** Line edit and history:
+*   #define USE_READLINE to use the GNU readline library.
+*
+*   To use another library for this, use the code below as a start.
+*   Make sure you #define lua_readline and lua_saveline accordingly.
+*   If you do not #define lua_readline, you'll get a version based on fgets
+*   that uses a static buffer of size MAXINPUT.
+*
+*
+*** Static Lua libraries to be loaded at startup:
+*   #define lua_userinit(L) to a Lua function that loads libraries; typically
+*	#define lua_userinit(L)	openstdlibs(L);myinit(L)
+*   or
+*	#define lua_userinit(L)	myinit(L)
+*
+*   Another way is to add the prototypes of the init functions here and
+*   #define LUA_EXTRALIBS accordingly. For example,
+*	#define LUA_EXTRALIBS {"mylib","luaopen_mylib"},
+*   Note the ending comma!
+*
+*
+*** Prompts:
+*   The stand-alone Lua interpreter uses two prompts: PROMPT and PROMPT2.
+*   PROMPT is the primary prompt, shown when the intepreter is ready to receive
+*   a new statement. PROMPT2 is the secondary prompt, shown while a statement
+*   is being entered but is still incomplete.
+*
+*
+*** Program name:
+*   Error messages usually show argv[0] as a program name. In systems that do
+*   not give a valid string as argv[0], error messages show PROGNAME instead.
+*
+*
+*/
+
+#ifdef USE_READLINE
+/*
+* This section implements of lua_readline and lua_saveline  for lua.c using
+* the GNU readline and history libraries.  It should also work with drop-in
+* replacements  such as  editline  and  libedit (you  may  have to  include
+* different headers, though).
+*
+*/
+
+#define lua_readline	myreadline
+#define lua_saveline	mysaveline
+
+#include <ctype.h>
+#include <readline/readline.h>
+#include <readline/history.h>
+
+static int myreadline (lua_State *L, const char *prompt) {
+  char *s=readline(prompt);
+  if (s==NULL)
+    return 0;
+  else {
+    lua_pushstring(L,s);
+    lua_pushliteral(L,"\n");
+    lua_concat(L,2);
+    free(s);
+    return 1;
+  }
+}
+
+static void mysaveline (lua_State *L, const char *s) {
+  const char *p;
+  for (p=s; isspace(*p); p++)
+    ;
+  if (*p!=0) {
+    size_t n=strlen(s)-1;
+    if (s[n]!='\n')
+      add_history(s);
+    else {
+      lua_pushlstring(L,s,n);
+      s=lua_tostring(L,-1);
+      add_history(s);
+      lua_remove(L,-1);
+    }
+  }
+}
+#endif
diff --git a/etc/setfallback.lua b/etc/setfallback.lua
deleted file mode 100644
index 783b8667..00000000
--- a/etc/setfallback.lua
+++ /dev/null
@@ -1,55 +0,0 @@
---------------------------------------------------------------
--- Definition of "setfallback" using tag methods
--- (for compatibility with old code)
---------------------------------------------------------------
-
-
--- default fallbacks for each event:
-local defaults = {
-  gettable = function () error('indexed expression not a table') end,
-  settable = function () error('indexed expression not a table') end,
-  index = function () return nil end,
-  getglobal = function () return nil end,
-  arith = function () error('number expected in arithmetic operation') end,
-  order = function () error('incompatible types in comparison') end,
-  concat = function () error('string expected in concatenation') end,
-  gc = function () return nil end,
-  ['function'] = function () error('called expression not a function') end,
-  error = function (s) write(_STDERR, s, '\n') end,
-}
-
-
-function setfallback (name, func)
-
-  -- set the given function as the tag method for all "standard" tags
-  -- (since some combinations may cause errors, use call to avoid messages)
-  local fillvalids = function (n, func)
-    call(settagmethod, {0, n, func}, 'x', nil)
-    call(settagmethod, {tag(0), n, func}, 'x', nil)
-    call(settagmethod, {tag(''), n, func}, 'x', nil)
-    call(settagmethod, {tag{}, n, func}, 'x', nil)
-    call(settagmethod, {tag(function () end), n, func}, 'x', nil)
-    call(settagmethod, {tag(settagmethod), n, func}, 'x', nil)
-    call(settagmethod, {tag(nil), n, func}, 'x', nil)
-  end
-
-  assert(type(func) == 'function')
-  local oldfunc
-  if name == 'error' then
-    oldfunc = seterrormethod(func)
-  elseif name == 'getglobal' then
-    oldfunc = settagmethod(tag(nil), 'getglobal', func)
-  elseif name == 'arith' then
-    oldfunc = gettagmethod(tag(0), 'pow')
-    foreach({"add", "sub", "mul", "div", "unm", "pow"},
-            function(_, n) %fillvalids(n, %func) end)
-  elseif name == 'order' then
-    oldfunc = gettagmethod(tag(nil), 'lt')
-    foreach({"lt", "gt", "le", "ge"},
-            function(_, n) %fillvalids(n, %func) end)
-  else
-    oldfunc = gettagmethod(tag(nil), name)
-    fillvalids(name, func)
-  end
-  return oldfunc or rawgettable(%defaults, name)
-end
diff --git a/etc/stdcall.lua b/etc/stdcall.lua
deleted file mode 100644
index 7eac5c2e..00000000
--- a/etc/stdcall.lua
+++ /dev/null
@@ -1,10 +0,0 @@
--- stdcall.lua
--- add __stdcall where appropriate
--- usage: lua stdcall.lua <lua.h >s_lua.h
--- usage: lua stdcall.lua <lapi.c >s_lapi.c
-
-T=read"*a"
-T=gsub(T,"(lua_%w+%s+%()","__stdcall %1")
-T=gsub(T,"(%*lua_CFunction)","__stdcall %1")
-
-write(T)
diff --git a/etc/trace.c b/etc/trace.c
index 7c0b86ed..c29f1c9d 100644
--- a/etc/trace.c
+++ b/etc/trace.c
@@ -1,56 +1,55 @@
 /*
-* trace.c
-* a simple execution tracer for Lua
+* trace.c -- a simple execution tracer for Lua
 */
 
 #include <stdio.h>
 #include <string.h>
 #include "lua.h"
 #include "lualib.h"
-#include "luadebug.h"
+#include "lauxlib.h"
 
-lua_State *lua_state = NULL;
-#define	L	lua_state	/* lazy! */
-
-static FILE* LOG;		/* output file */
+static FILE* LOG;		/* log file */
 static int I=0;			/* indentation level */
 
-static void linehook(lua_State *L, lua_Debug *ar)
-{
- fprintf(LOG,"%*sdo_line(%d)\t-- %d\n",I,"",ar->currentline,I);
-}
-
-static void callhook(lua_State *L, lua_Debug *ar)
+static void hook(lua_State *L, lua_Debug *ar)
 {
- fprintf(LOG,"%*sdo_%s\t-- %p %d\n",I,"",ar->event,ar->_func,I);
- if (*ar->event=='r') --I; else ++I;
+ const char* s="";
+ switch (ar->event)
+ {
+  case LUA_HOOKTAILRET: ar->event=LUA_HOOKRET;
+  case LUA_HOOKRET: s="return"; break;
+  case LUA_HOOKCALL: s="call"; break;
+  case LUA_HOOKLINE: s="line"; break;
+  default: break;
+ }
+ fprintf(LOG,"[%d]\t%*s%s\t-- %d\n",I,I,"",s,ar->currentline);
+ if (ar->event==LUA_HOOKCALL) ++I; else if (ar->event==LUA_HOOKRET) --I;
 }
 
-void start_trace(FILE* logfile)
+static void start_trace(lua_State *L, FILE* logfile)
 {
- lua_setlinehook(L,linehook);
- lua_setcallhook(L,callhook);
+ lua_sethook(L,hook,LUA_MASKCALL | LUA_MASKRET | LUA_MASKLINE, 0);
  LOG=logfile;
 }
 
-void stop_trace(void)
+static void stop_trace(lua_State *L)
 {
- lua_setlinehook(L,NULL);
- lua_setcallhook(L,NULL);
+ lua_sethook(L,NULL,0,0);
  fclose(LOG);
 }
 
 int main(void)
 {
  int rc;
- L=lua_open(0);
+ lua_State *L=lua_open();
  lua_baselibopen(L);
+ lua_tablibopen(L);
  lua_iolibopen(L);
  lua_strlibopen(L);
  lua_mathlibopen(L);
  lua_dblibopen(L);
- start_trace(stderr);
- rc=lua_dofile(L,0);
- stop_trace();
+ start_trace(L,stderr);
+ rc=lua_dofile(L,NULL);
+ stop_trace(L);
  return rc;
 }
diff --git a/include/Makefile b/include/Makefile
index 0a2dfd95..d75997d9 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -4,7 +4,7 @@ LUA= ..
 
 include $(LUA)/config
 
-SRCS= lua.h lualib.h luadebug.h lauxlib.h
+SRCS= lua.h lualib.h lauxlib.h
 
 all:
 
diff --git a/include/lauxlib.h b/include/lauxlib.h
index 9df0c8e8..450e16c7 100644
--- a/include/lauxlib.h
+++ b/include/lauxlib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.h,v 1.30 2000/10/30 12:38:50 roberto Exp $
+** $Id: lauxlib.h,v 1.60 2003/04/03 13:35:34 roberto Exp $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -16,29 +16,51 @@
 
 
 #ifndef LUALIB_API
-#define LUALIB_API	extern
+#define LUALIB_API	LUA_API
 #endif
 
 
-struct luaL_reg {
+
+typedef struct luaL_reg {
   const char *name;
   lua_CFunction func;
-};
+} luaL_reg;
+
+
+LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
+                               const luaL_reg *l, int nup);
+LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *e);
+LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *e);
+LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname);
+LUALIB_API int luaL_argerror (lua_State *L, int numarg, const char *extramsg);
+LUALIB_API const char *luaL_checklstring (lua_State *L, int numArg, size_t *l);
+LUALIB_API const char *luaL_optlstring (lua_State *L, int numArg,
+                                           const char *def, size_t *l);
+LUALIB_API lua_Number luaL_checknumber (lua_State *L, int numArg);
+LUALIB_API lua_Number luaL_optnumber (lua_State *L, int nArg, lua_Number def);
+
+LUALIB_API void luaL_checkstack (lua_State *L, int sz, const char *msg);
+LUALIB_API void luaL_checktype (lua_State *L, int narg, int t);
+LUALIB_API void luaL_checkany (lua_State *L, int narg);
 
+LUALIB_API int   luaL_newmetatable (lua_State *L, const char *tname);
+LUALIB_API void  luaL_getmetatable (lua_State *L, const char *tname);
+LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname);
 
-LUALIB_API void luaL_openlib (lua_State *L, const struct luaL_reg *l, int n);
-LUALIB_API void luaL_argerror (lua_State *L, int numarg, const char *extramsg);
-LUALIB_API const char *luaL_check_lstr (lua_State *L, int numArg, size_t *len);
-LUALIB_API const char *luaL_opt_lstr (lua_State *L, int numArg, const char *def, size_t *len);
-LUALIB_API double luaL_check_number (lua_State *L, int numArg);
-LUALIB_API double luaL_opt_number (lua_State *L, int numArg, double def);
+LUALIB_API void luaL_where (lua_State *L, int lvl);
+LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...);
 
-LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg);
-LUALIB_API void luaL_checktype (lua_State *L, int narg, int t);
-LUALIB_API void luaL_checkany (lua_State *L, int narg);
+LUALIB_API int luaL_findstring (const char *st, const char *const lst[]);
+
+LUALIB_API int luaL_ref (lua_State *L, int t);
+LUALIB_API void luaL_unref (lua_State *L, int t, int ref);
+
+LUALIB_API int luaL_getn (lua_State *L, int t);
+LUALIB_API void luaL_setn (lua_State *L, int t, int n);
 
-LUALIB_API void luaL_verror (lua_State *L, const char *fmt, ...);
-LUALIB_API int luaL_findstring (const char *name, const char *const list[]);
+LUALIB_API int luaL_loadfile (lua_State *L, const char *filename);
+LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t sz,
+                                const char *name);
 
 
 
@@ -48,15 +70,14 @@ LUALIB_API int luaL_findstring (const char *name, const char *const list[]);
 ** ===============================================================
 */
 
-#define luaL_arg_check(L, cond,numarg,extramsg) if (!(cond)) \
+#define luaL_argcheck(L, cond,numarg,extramsg) if (!(cond)) \
                                                luaL_argerror(L, numarg,extramsg)
-#define luaL_check_string(L,n)	(luaL_check_lstr(L, (n), NULL))
-#define luaL_opt_string(L,n,d)	(luaL_opt_lstr(L, (n), (d), NULL))
-#define luaL_check_int(L,n)	((int)luaL_check_number(L, n))
-#define luaL_check_long(L,n)	((long)luaL_check_number(L, n))
-#define luaL_opt_int(L,n,d)	((int)luaL_opt_number(L, n,d))
-#define luaL_opt_long(L,n,d)	((long)luaL_opt_number(L, n,d))
-#define luaL_openl(L,a)		luaL_openlib(L, a, (sizeof(a)/sizeof(a[0])))
+#define luaL_checkstring(L,n)	(luaL_checklstring(L, (n), NULL))
+#define luaL_optstring(L,n,d)	(luaL_optlstring(L, (n), (d), NULL))
+#define luaL_checkint(L,n)	((int)luaL_checknumber(L, n))
+#define luaL_checklong(L,n)	((long)luaL_checknumber(L, n))
+#define luaL_optint(L,n,d)	((int)luaL_optnumber(L, n,(lua_Number)(d)))
+#define luaL_optlong(L,n,d)	((long)luaL_optnumber(L, n,(lua_Number)(d)))
 
 
 /*
@@ -73,13 +94,13 @@ LUALIB_API int luaL_findstring (const char *name, const char *const list[]);
 
 typedef struct luaL_Buffer {
   char *p;			/* current position in buffer */
-  int level;
+  int lvl;  /* number of strings in the stack (level) */
   lua_State *L;
   char buffer[LUAL_BUFFERSIZE];
 } luaL_Buffer;
 
 #define luaL_putchar(B,c) \
-  ((void)((B)->p < &(B)->buffer[LUAL_BUFFERSIZE] || luaL_prepbuffer(B)), \
+  ((void)((B)->p < ((B)->buffer+LUAL_BUFFERSIZE) || luaL_prepbuffer(B)), \
    (*(B)->p++ = (char)(c)))
 
 #define luaL_addsize(B,n)	((B)->p += (n))
@@ -95,6 +116,30 @@ LUALIB_API void luaL_pushresult (luaL_Buffer *B);
 /* }====================================================== */
 
 
+
+/*
+** Compatibility macros and functions
+*/
+
+LUALIB_API int   lua_dofile (lua_State *L, const char *filename);
+LUALIB_API int   lua_dostring (lua_State *L, const char *str);
+LUALIB_API int   lua_dobuffer (lua_State *L, const char *buff, size_t sz,
+                               const char *n);
+
+
+#define luaL_check_lstr 	luaL_checklstring
+#define luaL_opt_lstr 	luaL_optlstring 
+#define luaL_check_number 	luaL_checknumber 
+#define luaL_opt_number	luaL_optnumber
+#define luaL_arg_check	luaL_argcheck
+#define luaL_check_string	luaL_checkstring
+#define luaL_opt_string	luaL_optstring
+#define luaL_check_int	luaL_checkint
+#define luaL_check_long	luaL_checklong
+#define luaL_opt_int	luaL_optint
+#define luaL_opt_long	luaL_optlong
+
+
 #endif
 
 
diff --git a/include/lua.h b/include/lua.h
index 660ecd80..0d827b10 100644
--- a/include/lua.h
+++ b/include/lua.h
@@ -1,9 +1,8 @@
 /*
-** $Id: lua.h,v 1.79a 2000/10/31 12:44:07 roberto Exp $
+** $Id: lua.h,v 1.175 2003/03/18 12:31:39 roberto Exp $
 ** Lua - An Extensible Extension Language
-** TeCGraf: Grupo de Tecnologia em Computacao Grafica, PUC-Rio, Brazil
-** e-mail: lua@tecgraf.puc-rio.br
-** www: http://www.tecgraf.puc-rio.br/lua/
+** Tecgraf: Computer Graphics Technology Group, PUC-Rio, Brazil
+** http://www.lua.org	mailto:info@lua.org
 ** See Copyright Notice at the end of this file
 */
 
@@ -11,45 +10,29 @@
 #ifndef lua_h
 #define lua_h
 
-
-/* definition of `size_t' */
+#include <stdarg.h>
 #include <stddef.h>
 
 
-/* mark for all API functions */
-#ifndef LUA_API
-#define LUA_API		extern
-#endif
-
-
-#define LUA_VERSION	"Lua 4.0.1"
-#define LUA_COPYRIGHT	"Copyright (C) 1994-2000 TeCGraf, PUC-Rio"
-#define LUA_AUTHORS 	"W. Celes, R. Ierusalimschy & L. H. de Figueiredo"
+#define LUA_VERSION	"Lua 5.0"
+#define LUA_COPYRIGHT	"Copyright (C) 1994-2003 Tecgraf, PUC-Rio"
+#define LUA_AUTHORS 	"R. Ierusalimschy, L. H. de Figueiredo & W. Celes"
 
 
-/* name of global variable with error handler */
-#define LUA_ERRORMESSAGE	"_ERRORMESSAGE"
-
-
-/* pre-defined references */
-#define LUA_NOREF	(-2)
-#define LUA_REFNIL	(-1)
-#define LUA_REFREGISTRY	0
-
-/* pre-defined tags */
-#define LUA_ANYTAG	(-1)
-#define LUA_NOTAG	(-2)
 
-
-/* option for multiple returns in lua_call */
+/* option for multiple returns in `lua_pcall' and `lua_call' */
 #define LUA_MULTRET	(-1)
 
 
-/* minimum stack available for a C function */
-#define LUA_MINSTACK	20
+/*
+** pseudo-indices
+*/
+#define LUA_REGISTRYINDEX	(-10000)
+#define LUA_GLOBALSINDEX	(-10001)
+#define lua_upvalueindex(i)	(LUA_GLOBALSINDEX-(i))
 
 
-/* error codes for lua_do* */
+/* error codes for `lua_load' and `lua_pcall' */
 #define LUA_ERRRUN	1
 #define LUA_ERRFILE	2
 #define LUA_ERRSYNTAX	3
@@ -61,107 +44,164 @@ typedef struct lua_State lua_State;
 
 typedef int (*lua_CFunction) (lua_State *L);
 
+
+/*
+** functions that read/write blocks when loading/dumping Lua chunks
+*/
+typedef const char * (*lua_Chunkreader) (lua_State *L, void *ud, size_t *sz);
+
+typedef int (*lua_Chunkwriter) (lua_State *L, const void* p,
+                                size_t sz, void* ud);
+
+
 /*
-** types returned by `lua_type'
+** basic types
 */
 #define LUA_TNONE	(-1)
 
-#define LUA_TUSERDATA	0
-#define LUA_TNIL	1
-#define LUA_TNUMBER	2
-#define LUA_TSTRING	3
-#define LUA_TTABLE	4
-#define LUA_TFUNCTION	5
+#define LUA_TNIL	0
+#define LUA_TBOOLEAN	1
+#define LUA_TLIGHTUSERDATA	2
+#define LUA_TNUMBER	3
+#define LUA_TSTRING	4
+#define LUA_TTABLE	5
+#define LUA_TFUNCTION	6
+#define LUA_TUSERDATA	7
+#define LUA_TTHREAD	8
+
+
+/* minimum Lua stack available to a C function */
+#define LUA_MINSTACK	20
 
 
+/*
+** generic extra include file
+*/
+#ifdef LUA_USER_H
+#include LUA_USER_H
+#endif
+
+
+/* type of numbers in Lua */
+#ifndef LUA_NUMBER
+typedef double lua_Number;
+#else
+typedef LUA_NUMBER lua_Number;
+#endif
+
+
+/* mark for all API functions */
+#ifndef LUA_API
+#define LUA_API		extern
+#endif
+
 
 /*
 ** state manipulation
 */
-LUA_API lua_State *lua_open (int stacksize);
+LUA_API lua_State *lua_open (void);
 LUA_API void       lua_close (lua_State *L);
+LUA_API lua_State *lua_newthread (lua_State *L);
+
+LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);
 
 
 /*
 ** basic stack manipulation
 */
 LUA_API int   lua_gettop (lua_State *L);
-LUA_API void  lua_settop (lua_State *L, int index);
-LUA_API void  lua_pushvalue (lua_State *L, int index);
-LUA_API void  lua_remove (lua_State *L, int index);
-LUA_API void  lua_insert (lua_State *L, int index);
-LUA_API int   lua_stackspace (lua_State *L);
+LUA_API void  lua_settop (lua_State *L, int idx);
+LUA_API void  lua_pushvalue (lua_State *L, int idx);
+LUA_API void  lua_remove (lua_State *L, int idx);
+LUA_API void  lua_insert (lua_State *L, int idx);
+LUA_API void  lua_replace (lua_State *L, int idx);
+LUA_API int   lua_checkstack (lua_State *L, int sz);
+
+LUA_API void  lua_xmove (lua_State *from, lua_State *to, int n);
 
 
 /*
 ** access functions (stack -> C)
 */
 
-LUA_API int            lua_type (lua_State *L, int index);
-LUA_API const char    *lua_typename (lua_State *L, int t);
-LUA_API int            lua_isnumber (lua_State *L, int index);
-LUA_API int            lua_isstring (lua_State *L, int index);
-LUA_API int            lua_iscfunction (lua_State *L, int index);
-LUA_API int            lua_tag (lua_State *L, int index);
+LUA_API int             lua_isnumber (lua_State *L, int idx);
+LUA_API int             lua_isstring (lua_State *L, int idx);
+LUA_API int             lua_iscfunction (lua_State *L, int idx);
+LUA_API int             lua_isuserdata (lua_State *L, int idx);
+LUA_API int             lua_type (lua_State *L, int idx);
+LUA_API const char     *lua_typename (lua_State *L, int tp);
 
-LUA_API int            lua_equal (lua_State *L, int index1, int index2);
-LUA_API int            lua_lessthan (lua_State *L, int index1, int index2);
+LUA_API int            lua_equal (lua_State *L, int idx1, int idx2);
+LUA_API int            lua_rawequal (lua_State *L, int idx1, int idx2);
+LUA_API int            lua_lessthan (lua_State *L, int idx1, int idx2);
 
-LUA_API double         lua_tonumber (lua_State *L, int index);
-LUA_API const char    *lua_tostring (lua_State *L, int index);
-LUA_API size_t         lua_strlen (lua_State *L, int index);
-LUA_API lua_CFunction  lua_tocfunction (lua_State *L, int index);
-LUA_API void	      *lua_touserdata (lua_State *L, int index);
-LUA_API const void    *lua_topointer (lua_State *L, int index);
+LUA_API lua_Number      lua_tonumber (lua_State *L, int idx);
+LUA_API int             lua_toboolean (lua_State *L, int idx);
+LUA_API const char     *lua_tostring (lua_State *L, int idx);
+LUA_API size_t          lua_strlen (lua_State *L, int idx);
+LUA_API lua_CFunction   lua_tocfunction (lua_State *L, int idx);
+LUA_API void	       *lua_touserdata (lua_State *L, int idx);
+LUA_API lua_State      *lua_tothread (lua_State *L, int idx);
+LUA_API const void     *lua_topointer (lua_State *L, int idx);
 
 
 /*
 ** push functions (C -> stack)
 */
 LUA_API void  lua_pushnil (lua_State *L);
-LUA_API void  lua_pushnumber (lua_State *L, double n);
-LUA_API void  lua_pushlstring (lua_State *L, const char *s, size_t len);
+LUA_API void  lua_pushnumber (lua_State *L, lua_Number n);
+LUA_API void  lua_pushlstring (lua_State *L, const char *s, size_t l);
 LUA_API void  lua_pushstring (lua_State *L, const char *s);
+LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
+                                                    va_list argp);
+LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...);
 LUA_API void  lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);
-LUA_API void  lua_pushusertag (lua_State *L, void *u, int tag);
+LUA_API void  lua_pushboolean (lua_State *L, int b);
+LUA_API void  lua_pushlightuserdata (lua_State *L, void *p);
 
 
 /*
 ** get functions (Lua -> stack)
 */
-LUA_API void  lua_getglobal (lua_State *L, const char *name);
-LUA_API void  lua_gettable (lua_State *L, int index);
-LUA_API void  lua_rawget (lua_State *L, int index);
-LUA_API void  lua_rawgeti (lua_State *L, int index, int n);
-LUA_API void  lua_getglobals (lua_State *L);
-LUA_API void  lua_gettagmethod (lua_State *L, int tag, const char *event);
-LUA_API int   lua_getref (lua_State *L, int ref);
+LUA_API void  lua_gettable (lua_State *L, int idx);
+LUA_API void  lua_rawget (lua_State *L, int idx);
+LUA_API void  lua_rawgeti (lua_State *L, int idx, int n);
 LUA_API void  lua_newtable (lua_State *L);
+LUA_API void *lua_newuserdata (lua_State *L, size_t sz);
+LUA_API int   lua_getmetatable (lua_State *L, int objindex);
+LUA_API void  lua_getfenv (lua_State *L, int idx);
 
 
 /*
 ** set functions (stack -> Lua)
 */
-LUA_API void  lua_setglobal (lua_State *L, const char *name);
-LUA_API void  lua_settable (lua_State *L, int index);
-LUA_API void  lua_rawset (lua_State *L, int index);
-LUA_API void  lua_rawseti (lua_State *L, int index, int n);
-LUA_API void  lua_setglobals (lua_State *L);
-LUA_API void  lua_settagmethod (lua_State *L, int tag, const char *event);
-LUA_API int   lua_ref (lua_State *L, int lock);
+LUA_API void  lua_settable (lua_State *L, int idx);
+LUA_API void  lua_rawset (lua_State *L, int idx);
+LUA_API void  lua_rawseti (lua_State *L, int idx, int n);
+LUA_API int   lua_setmetatable (lua_State *L, int objindex);
+LUA_API int   lua_setfenv (lua_State *L, int idx);
+
+
+/*
+** `load' and `call' functions (load and run Lua code)
+*/
+LUA_API void  lua_call (lua_State *L, int nargs, int nresults);
+LUA_API int   lua_pcall (lua_State *L, int nargs, int nresults, int errfunc);
+LUA_API int lua_cpcall (lua_State *L, lua_CFunction func, void *ud);
+LUA_API int   lua_load (lua_State *L, lua_Chunkreader reader, void *dt,
+                        const char *chunkname);
+
+LUA_API int lua_dump (lua_State *L, lua_Chunkwriter writer, void *data);
 
 
 /*
-** "do" functions (run Lua code)
+** coroutine functions
 */
-LUA_API int   lua_call (lua_State *L, int nargs, int nresults);
-LUA_API void  lua_rawcall (lua_State *L, int nargs, int nresults);
-LUA_API int   lua_dofile (lua_State *L, const char *filename);
-LUA_API int   lua_dostring (lua_State *L, const char *str);
-LUA_API int   lua_dobuffer (lua_State *L, const char *buff, size_t size, const char *name);
+LUA_API int  lua_yield (lua_State *L, int nresults);
+LUA_API int  lua_resume (lua_State *L, int narg);
 
 /*
-** Garbage-collection functions
+** garbage-collection functions
 */
 LUA_API int   lua_getgcthreshold (lua_State *L);
 LUA_API int   lua_getgccount (lua_State *L);
@@ -170,20 +210,15 @@ LUA_API void  lua_setgcthreshold (lua_State *L, int newthreshold);
 /*
 ** miscellaneous functions
 */
-LUA_API int   lua_newtag (lua_State *L);
-LUA_API int   lua_copytagmethods (lua_State *L, int tagto, int tagfrom);
-LUA_API void  lua_settag (lua_State *L, int tag);
 
-LUA_API void  lua_error (lua_State *L, const char *s);
+LUA_API const char *lua_version (void);
 
-LUA_API void  lua_unref (lua_State *L, int ref);
+LUA_API int   lua_error (lua_State *L);
 
-LUA_API int   lua_next (lua_State *L, int index);
-LUA_API int   lua_getn (lua_State *L, int index);
+LUA_API int   lua_next (lua_State *L, int idx);
 
 LUA_API void  lua_concat (lua_State *L, int n);
 
-LUA_API void *lua_newuserdata (lua_State *L, size_t size);
 
 
 /* 
@@ -192,57 +227,165 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size);
 ** ===============================================================
 */
 
+#define lua_boxpointer(L,u) \
+	(*(void **)(lua_newuserdata(L, sizeof(void *))) = (u))
+
+#define lua_unboxpointer(L,i)	(*(void **)(lua_touserdata(L, i)))
+
 #define lua_pop(L,n)		lua_settop(L, -(n)-1)
 
-#define lua_register(L,n,f)	(lua_pushcfunction(L, f), lua_setglobal(L, n))
-#define lua_pushuserdata(L,u)	lua_pushusertag(L, u, 0)
+#define lua_register(L,n,f) \
+	(lua_pushstring(L, n), \
+	 lua_pushcfunction(L, f), \
+	 lua_settable(L, LUA_GLOBALSINDEX))
+
 #define lua_pushcfunction(L,f)	lua_pushcclosure(L, f, 0)
-#define lua_clonetag(L,t)	lua_copytagmethods(L, lua_newtag(L), (t))
 
 #define lua_isfunction(L,n)	(lua_type(L,n) == LUA_TFUNCTION)
 #define lua_istable(L,n)	(lua_type(L,n) == LUA_TTABLE)
-#define lua_isuserdata(L,n)	(lua_type(L,n) == LUA_TUSERDATA)
+#define lua_islightuserdata(L,n)	(lua_type(L,n) == LUA_TLIGHTUSERDATA)
 #define lua_isnil(L,n)		(lua_type(L,n) == LUA_TNIL)
-#define lua_isnull(L,n)		(lua_type(L,n) == LUA_TNONE)
+#define lua_isboolean(L,n)	(lua_type(L,n) == LUA_TBOOLEAN)
+#define lua_isnone(L,n)		(lua_type(L,n) == LUA_TNONE)
+#define lua_isnoneornil(L, n)	(lua_type(L,n) <= 0)
+
+#define lua_pushliteral(L, s)	\
+	lua_pushlstring(L, "" s, (sizeof(s)/sizeof(char))-1)
 
-#define lua_getregistry(L)	lua_getref(L, LUA_REFREGISTRY)
 
+
+/*
+** compatibility macros and functions
+*/
+
+
+LUA_API int lua_pushupvalues (lua_State *L);
+
+#define lua_getregistry(L)	lua_pushvalue(L, LUA_REGISTRYINDEX)
+#define lua_setglobal(L,s)	\
+   (lua_pushstring(L, s), lua_insert(L, -2), lua_settable(L, LUA_GLOBALSINDEX))
+
+#define lua_getglobal(L,s)	\
+		(lua_pushstring(L, s), lua_gettable(L, LUA_GLOBALSINDEX))
+
+
+/* compatibility with ref system */
+
+/* pre-defined references */
+#define LUA_NOREF	(-2)
+#define LUA_REFNIL	(-1)
+
+#define lua_ref(L,lock)	((lock) ? luaL_ref(L, LUA_REGISTRYINDEX) : \
+      (lua_pushstring(L, "unlocked references are obsolete"), lua_error(L), 0))
+
+#define lua_unref(L,ref)	luaL_unref(L, LUA_REGISTRYINDEX, (ref))
+
+#define lua_getref(L,ref)	lua_rawgeti(L, LUA_REGISTRYINDEX, ref)
+
+
+
+/*
+** {======================================================================
+** useful definitions for Lua kernel and libraries
+** =======================================================================
+*/
+
+/* formats for Lua numbers */
+#ifndef LUA_NUMBER_SCAN
+#define LUA_NUMBER_SCAN		"%lf"
 #endif
 
+#ifndef LUA_NUMBER_FMT
+#define LUA_NUMBER_FMT		"%.14g"
+#endif
+
+/* }====================================================================== */
+
+
+/*
+** {======================================================================
+** Debug API
+** =======================================================================
+*/
+
+
+/*
+** Event codes
+*/
+#define LUA_HOOKCALL	0
+#define LUA_HOOKRET	1
+#define LUA_HOOKLINE	2
+#define LUA_HOOKCOUNT	3
+#define LUA_HOOKTAILRET 4
+
+
+/*
+** Event masks
+*/
+#define LUA_MASKCALL	(1 << LUA_HOOKCALL)
+#define LUA_MASKRET	(1 << LUA_HOOKRET)
+#define LUA_MASKLINE	(1 << LUA_HOOKLINE)
+#define LUA_MASKCOUNT	(1 << LUA_HOOKCOUNT)
+
+typedef struct lua_Debug lua_Debug;  /* activation record */
+
+typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
+
+
+LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar);
+LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
+LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);
+LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);
+LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n);
+LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n);
+
+LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count);
+LUA_API lua_Hook lua_gethook (lua_State *L);
+LUA_API int lua_gethookmask (lua_State *L);
+LUA_API int lua_gethookcount (lua_State *L);
+
+
+#define LUA_IDSIZE	60
+
+struct lua_Debug {
+  int event;
+  const char *name;	/* (n) */
+  const char *namewhat;	/* (n) `global', `local', `field', `method' */
+  const char *what;	/* (S) `Lua', `C', `main', `tail' */
+  const char *source;	/* (S) */
+  int currentline;	/* (l) */
+  int nups;		/* (u) number of upvalues */
+  int linedefined;	/* (S) */
+  char short_src[LUA_IDSIZE]; /* (S) */
+  /* private part */
+  int i_ci;  /* active function */
+};
+
+/* }====================================================================== */
 
 
 /******************************************************************************
-* Copyright (C) 1994-2000 TeCGraf, PUC-Rio.  All rights reserved.
-* 
-* Permission is hereby granted, without written agreement and without license
-* or royalty fees, to use, copy, modify, and distribute this software and its
-* documentation for any purpose, including commercial applications, subject to
+* Copyright (C) 1994-2003 Tecgraf, PUC-Rio.  All rights reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining
+* a copy of this software and associated documentation files (the
+* "Software"), to deal in the Software without restriction, including
+* without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to
+* permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
-* 
-*  - The above copyright notice and this permission notice shall appear in all
-*    copies or substantial portions of this software.
-* 
-*  - The origin of this software must not be misrepresented; you must not
-*    claim that you wrote the original software. If you use this software in a
-*    product, an acknowledgment in the product documentation would be greatly
-*    appreciated (but it is not required).
-* 
-*  - Altered source versions must be plainly marked as such, and must not be
-*    misrepresented as being the original software.
-*    
-* The authors specifically disclaim any warranties, including, but not limited
-* to, the implied warranties of merchantability and fitness for a particular
-* purpose.  The software provided hereunder is on an "as is" basis, and the
-* authors have no obligation to provide maintenance, support, updates,
-* enhancements, or modifications.  In no event shall TeCGraf, PUC-Rio, or the
-* authors be held liable to any party for direct, indirect, special,
-* incidental, or consequential damages arising out of the use of this software
-* and its documentation.
-* 
-* The Lua language and this implementation have been entirely designed and
-* written by Waldemar Celes Filho, Roberto Ierusalimschy and
-* Luiz Henrique de Figueiredo at TeCGraf, PUC-Rio.
 *
-* This implementation contains no third-party code.
+* The above copyright notice and this permission notice shall be
+* included in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 ******************************************************************************/
 
+
+#endif
diff --git a/include/luadebug.h b/include/luadebug.h
deleted file mode 100644
index 77753d37..00000000
--- a/include/luadebug.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
-** $Id: luadebug.h,v 1.17 2000/10/30 12:38:50 roberto Exp $
-** Debugging API
-** See Copyright Notice in lua.h
-*/
-
-
-#ifndef luadebug_h
-#define luadebug_h
-
-
-#include "lua.h"
-
-typedef struct lua_Debug lua_Debug;  /* activation record */
-typedef struct lua_Localvar lua_Localvar;
-
-typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);
-
-
-LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar);
-LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);
-LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);
-LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);
-
-LUA_API lua_Hook lua_setcallhook (lua_State *L, lua_Hook func);
-LUA_API lua_Hook lua_setlinehook (lua_State *L, lua_Hook func);
-
-
-#define LUA_IDSIZE	60
-
-struct lua_Debug {
-  const char *event;     /* `call', `return' */
-  int currentline;       /* (l) */
-  const char *name;      /* (n) */
-  const char *namewhat;  /* (n) `global', `tag method', `local', `field' */
-  int nups;              /* (u) number of upvalues */
-  int linedefined;       /* (S) */
-  const char *what;      /* (S) `Lua' function, `C' function, Lua `main' */
-  const char *source;    /* (S) */
-  char short_src[LUA_IDSIZE]; /* (S) */
-  /* private part */
-  struct lua_TObject *_func;  /* active function */
-};
-
-
-#endif
diff --git a/include/lualib.h b/include/lualib.h
index fe48cb10..e22c4c30 100644
--- a/include/lualib.h
+++ b/include/lualib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lualib.h,v 1.14 2000/10/27 16:15:53 roberto Exp $
+** $Id: lualib.h,v 1.28 2003/03/18 12:24:26 roberto Exp $
 ** Lua standard libraries
 ** See Copyright Notice in lua.h
 */
@@ -12,23 +12,45 @@
 
 
 #ifndef LUALIB_API
-#define LUALIB_API	extern
+#define LUALIB_API	LUA_API
 #endif
 
 
-#define LUA_ALERT               "_ALERT"
+#define LUA_COLIBNAME	"coroutine"
+LUALIB_API int luaopen_base (lua_State *L);
 
-LUALIB_API void lua_baselibopen (lua_State *L);
-LUALIB_API void lua_iolibopen (lua_State *L);
-LUALIB_API void lua_strlibopen (lua_State *L);
-LUALIB_API void lua_mathlibopen (lua_State *L);
-LUALIB_API void lua_dblibopen (lua_State *L);
+#define LUA_TABLIBNAME	"table"
+LUALIB_API int luaopen_table (lua_State *L);
 
+#define LUA_IOLIBNAME	"io"
+#define LUA_OSLIBNAME	"os"
+LUALIB_API int luaopen_io (lua_State *L);
 
+#define LUA_STRLIBNAME	"string"
+LUALIB_API int luaopen_string (lua_State *L);
 
-/* Auxiliary functions (private) */
+#define LUA_MATHLIBNAME	"math"
+LUALIB_API int luaopen_math (lua_State *L);
 
-const char *luaI_classend (lua_State *L, const char *p);
-int luaI_singlematch (int c, const char *p, const char *ep);
+#define LUA_DBLIBNAME	"debug"
+LUALIB_API int luaopen_debug (lua_State *L);
+
+
+LUALIB_API int luaopen_loadlib (lua_State *L);
+
+
+/* to help testing the libraries */
+#ifndef lua_assert
+#define lua_assert(c)		/* empty */
+#endif
+
+
+/* compatibility code */
+#define lua_baselibopen	luaopen_base
+#define lua_tablibopen	luaopen_table
+#define lua_iolibopen	luaopen_io
+#define lua_strlibopen	luaopen_string
+#define lua_mathlibopen	luaopen_math
+#define lua_dblibopen	luaopen_debug
 
 #endif
diff --git a/src/Makefile b/src/Makefile
index 66e0ea8d..bf64c03f 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -9,11 +9,13 @@ OBJS=	\
 	lcode.o \
 	ldebug.o \
 	ldo.o \
+	ldump.o \
 	lfunc.o \
 	lgc.o \
 	llex.o \
 	lmem.o \
 	lobject.o \
+	lopcodes.o \
 	lparser.o \
 	lstate.o \
 	lstring.o \
@@ -29,11 +31,13 @@ SRCS=	\
 	lcode.c \
 	ldebug.c \
 	ldo.c \
+	ldump.c \
 	lfunc.c \
 	lgc.c \
 	llex.c \
 	lmem.c \
 	lobject.c \
+	lopcodes.c \
 	lparser.c \
 	lstate.c \
 	lstring.c \
@@ -65,9 +69,9 @@ SRCS=	\
 
 T= $(LIB)/liblua.a
 
-all: $T
+all:	$T
 
-$T: $(OBJS)
+$T:	$(OBJS)
 	$(AR) $@ $(OBJS)
 	$(RANLIB) $@
 
diff --git a/src/README b/src/README
new file mode 100644
index 00000000..e5375981
--- /dev/null
+++ b/src/README
@@ -0,0 +1,5 @@
+This is the Lua core.
+
+The standard Lua library are in lib/.
+A sample interpreter is in lua/.
+A standalone compiler is in luac/.
diff --git a/src/lapi.c b/src/lapi.c
index 54c2cba4..d5dd9ca4 100644
--- a/src/lapi.c
+++ b/src/lapi.c
@@ -1,15 +1,19 @@
 /*
-** $Id: lapi.c,v 1.110a 2000/10/30 12:50:09 roberto Exp $
+** $Id: lapi.c,v 1.235 2003/04/07 14:36:08 roberto Exp $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
 
 
+#include <assert.h>
 #include <string.h>
 
+#define lapi_c
+
 #include "lua.h"
 
 #include "lapi.h"
+#include "ldebug.h"
 #include "ldo.h"
 #include "lfunc.h"
 #include "lgc.h"
@@ -19,43 +23,128 @@
 #include "lstring.h"
 #include "ltable.h"
 #include "ltm.h"
+#include "lundump.h"
 #include "lvm.h"
 
 
-const char lua_ident[] = "$Lua: " LUA_VERSION " " LUA_COPYRIGHT " $\n"
-                               "$Authors: " LUA_AUTHORS " $";
+const char lua_ident[] =
+  "$Lua: " LUA_VERSION " " LUA_COPYRIGHT " $\n"
+  "$Authors: " LUA_AUTHORS " $\n"
+  "$URL: www.lua.org $\n";
+
 
 
+#ifndef api_check
+#define api_check(L, o)		/*{ assert(o); }*/
+#endif
 
-#define Index(L,i)	((i) >= 0 ? (L->Cbase+((i)-1)) : (L->top+(i)))
+#define api_checknelems(L, n)	api_check(L, (n) <= (L->top - L->base))
 
-#define api_incr_top(L)	incr_top
+#define api_incr_top(L)   {api_check(L, L->top < L->ci->top); L->top++;}
 
 
 
 
-TObject *luaA_index (lua_State *L, int index) {
-  return Index(L, index);
+static TObject *negindex (lua_State *L, int idx) {
+  if (idx > LUA_REGISTRYINDEX) {
+    api_check(L, idx != 0 && -idx <= L->top - L->base);
+    return L->top+idx;
+  }
+  else switch (idx) {  /* pseudo-indices */
+    case LUA_REGISTRYINDEX: return registry(L);
+    case LUA_GLOBALSINDEX: return gt(L);
+    default: {
+      TObject *func = (L->base - 1);
+      idx = LUA_GLOBALSINDEX - idx;
+      lua_assert(iscfunction(func));
+      return (idx <= clvalue(func)->c.nupvalues)
+                ? &clvalue(func)->c.upvalue[idx-1]
+                : NULL;
+    }
+  }
+}
+
+
+static TObject *luaA_index (lua_State *L, int idx) {
+  if (idx > 0) {
+    api_check(L, idx <= L->top - L->base);
+    return L->base + idx - 1;
+  }
+  else {
+    TObject *o = negindex(L, idx);
+    api_check(L, o != NULL);
+    return o;
+  }
 }
 
 
-static TObject *luaA_indexAcceptable (lua_State *L, int index) {
-  if (index >= 0) {
-    TObject *o = L->Cbase+(index-1);
+static TObject *luaA_indexAcceptable (lua_State *L, int idx) {
+  if (idx > 0) {
+    TObject *o = L->base+(idx-1);
+    api_check(L, idx <= L->stack_last - L->base);
     if (o >= L->top) return NULL;
     else return o;
   }
-  else return L->top+index;
+  else
+    return negindex(L, idx);
 }
 
 
 void luaA_pushobject (lua_State *L, const TObject *o) {
-  *L->top = *o;
-  incr_top;
+  setobj2s(L->top, o);
+  incr_top(L);
+}
+
+
+LUA_API int lua_checkstack (lua_State *L, int size) {
+  int res;
+  lua_lock(L);
+  if ((L->top - L->base + size) > LUA_MAXCSTACK)
+    res = 0;  /* stack overflow */
+  else {
+    luaD_checkstack(L, size);
+    if (L->ci->top < L->top + size)
+      L->ci->top = L->top + size;
+    res = 1;
+  }
+  lua_unlock(L);
+  return res;
 }
 
-LUA_API int lua_stackspace (lua_State *L) {
-  return (L->stack_last - L->top);
+
+LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
+  int i;
+  lua_lock(to);
+  api_checknelems(from, n);
+  from->top -= n;
+  for (i = 0; i < n; i++) {
+    setobj2s(to->top, from->top + i);
+    api_incr_top(to);
+  }
+  lua_unlock(to);
+}
+
+
+LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
+  lua_CFunction old;
+  lua_lock(L);
+  old = G(L)->panic;
+  G(L)->panic = panicf;
+  lua_unlock(L);
+  return old;
+}
+
+
+LUA_API lua_State *lua_newthread (lua_State *L) {
+  lua_State *L1;
+  lua_lock(L);
+  luaC_checkGC(L);
+  L1 = luaE_newthread(L);
+  setthvalue(L->top, L1);
+  api_incr_top(L);
+  lua_unlock(L);
+  lua_userstateopen(L1);
+  return L1;
 }
 
 
@@ -66,37 +155,61 @@ LUA_API int lua_stackspace (lua_State *L) {
 
 
 LUA_API int lua_gettop (lua_State *L) {
-  return (L->top - L->Cbase);
+  return (L->top - L->base);
 }
 
 
-LUA_API void lua_settop (lua_State *L, int index) {
-  if (index >= 0)
-    luaD_adjusttop(L, L->Cbase, index);
-  else
-    L->top = L->top+index+1;  /* index is negative */
+LUA_API void lua_settop (lua_State *L, int idx) {
+  lua_lock(L);
+  if (idx >= 0) {
+    api_check(L, idx <= L->stack_last - L->base);
+    while (L->top < L->base + idx)
+      setnilvalue(L->top++);
+    L->top = L->base + idx;
+  }
+  else {
+    api_check(L, -(idx+1) <= (L->top - L->base));
+    L->top += idx+1;  /* `subtract' index (index is negative) */
+  }
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_remove (lua_State *L, int index) {
-  StkId p = luaA_index(L, index);
-  while (++p < L->top) *(p-1) = *p;
+LUA_API void lua_remove (lua_State *L, int idx) {
+  StkId p;
+  lua_lock(L);
+  p = luaA_index(L, idx);
+  while (++p < L->top) setobjs2s(p-1, p);
   L->top--;
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_insert (lua_State *L, int index) {
-  StkId p = luaA_index(L, index);
+LUA_API void lua_insert (lua_State *L, int idx) {
+  StkId p;
   StkId q;
-  for (q = L->top; q>p; q--)
-    *q = *(q-1);
-  *p = *L->top;
+  lua_lock(L);
+  p = luaA_index(L, idx);
+  for (q = L->top; q>p; q--) setobjs2s(q, q-1);
+  setobjs2s(p, L->top);
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_pushvalue (lua_State *L, int index) {
-  *L->top = *luaA_index(L, index);
+LUA_API void lua_replace (lua_State *L, int idx) {
+  lua_lock(L);
+  api_checknelems(L, 1);
+  setobj(luaA_index(L, idx), L->top - 1);  /* write barrier */
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushvalue (lua_State *L, int idx) {
+  lua_lock(L);
+  setobj2s(L->top, luaA_index(L, idx));
   api_incr_top(L);
+  lua_unlock(L);
 }
 
 
@@ -106,93 +219,167 @@ LUA_API void lua_pushvalue (lua_State *L, int index) {
 */
 
 
-LUA_API int lua_type (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
+LUA_API int lua_type (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
   return (o == NULL) ? LUA_TNONE : ttype(o);
 }
 
+
 LUA_API const char *lua_typename (lua_State *L, int t) {
   UNUSED(L);
-  return (t == LUA_TNONE) ? "no value" : luaO_typenames[t];
+  return (t == LUA_TNONE) ? "no value" : luaT_typenames[t];
 }
 
 
-LUA_API int lua_iscfunction (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
+LUA_API int lua_iscfunction (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
   return (o == NULL) ? 0 : iscfunction(o);
 }
 
-LUA_API int lua_isnumber (lua_State *L, int index) {
-  TObject *o = luaA_indexAcceptable(L, index);
-  return (o == NULL) ? 0 : (tonumber(o) == 0);
+
+LUA_API int lua_isnumber (lua_State *L, int idx) {
+  TObject n;
+  const TObject *o = luaA_indexAcceptable(L, idx);
+  return (o != NULL && tonumber(o, &n));
 }
 
-LUA_API int lua_isstring (lua_State *L, int index) {
-  int t = lua_type(L, index);
+
+LUA_API int lua_isstring (lua_State *L, int idx) {
+  int t = lua_type(L, idx);
   return (t == LUA_TSTRING || t == LUA_TNUMBER);
 }
 
 
-LUA_API int lua_tag (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL) ? LUA_NOTAG : luaT_tag(o);
+LUA_API int lua_isuserdata (lua_State *L, int idx) {
+  const TObject *o = luaA_indexAcceptable(L, idx);
+  return (o != NULL && (ttisuserdata(o) || ttislightuserdata(o)));
 }
 
-LUA_API int lua_equal (lua_State *L, int index1, int index2) {
+
+LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
   StkId o1 = luaA_indexAcceptable(L, index1);
   StkId o2 = luaA_indexAcceptable(L, index2);
-  if (o1 == NULL || o2 == NULL) return 0;  /* index out-of-range */
-  else return luaO_equalObj(o1, o2);
+  return (o1 == NULL || o2 == NULL) ? 0  /* index out of range */
+                                    : luaO_rawequalObj(o1, o2);
+}
+
+
+LUA_API int lua_equal (lua_State *L, int index1, int index2) {
+  StkId o1, o2;
+  int i;
+  lua_lock(L);  /* may call tag method */
+  o1 = luaA_indexAcceptable(L, index1);
+  o2 = luaA_indexAcceptable(L, index2);
+  i = (o1 == NULL || o2 == NULL) ? 0  /* index out of range */
+                                 : equalobj(L, o1, o2);
+  lua_unlock(L);
+  return i;
 }
 
+
 LUA_API int lua_lessthan (lua_State *L, int index1, int index2) {
-  StkId o1 = luaA_indexAcceptable(L, index1);
-  StkId o2 = luaA_indexAcceptable(L, index2);
-  if (o1 == NULL || o2 == NULL) return 0;  /* index out-of-range */
-  else return luaV_lessthan(L, o1, o2, L->top);
+  StkId o1, o2;
+  int i;
+  lua_lock(L);  /* may call tag method */
+  o1 = luaA_indexAcceptable(L, index1);
+  o2 = luaA_indexAcceptable(L, index2);
+  i = (o1 == NULL || o2 == NULL) ? 0  /* index out-of-range */
+                                 : luaV_lessthan(L, o1, o2);
+  lua_unlock(L);
+  return i;
 }
 
 
 
-LUA_API double lua_tonumber (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL || tonumber(o)) ? 0 : nvalue(o);
+LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
+  TObject n;
+  const TObject *o = luaA_indexAcceptable(L, idx);
+  if (o != NULL && tonumber(o, &n))
+    return nvalue(o);
+  else
+    return 0;
 }
 
-LUA_API const char *lua_tostring (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL || tostring(L, o)) ? NULL : svalue(o);
+
+LUA_API int lua_toboolean (lua_State *L, int idx) {
+  const TObject *o = luaA_indexAcceptable(L, idx);
+  return (o != NULL) && !l_isfalse(o);
 }
 
-LUA_API size_t lua_strlen (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL || tostring(L, o)) ? 0 : tsvalue(o)->len;
+
+LUA_API const char *lua_tostring (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
+  if (o == NULL)
+    return NULL;
+  else if (ttisstring(o))
+    return svalue(o);
+  else {
+    const char *s;
+    lua_lock(L);  /* `luaV_tostring' may create a new string */
+    s = (luaV_tostring(L, o) ? svalue(o) : NULL);
+    luaC_checkGC(L);
+    lua_unlock(L);
+    return s;
+  }
 }
 
-LUA_API lua_CFunction lua_tocfunction (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL || !iscfunction(o)) ? NULL : clvalue(o)->f.c;
+
+LUA_API size_t lua_strlen (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
+  if (o == NULL)
+    return 0;
+  else if (ttisstring(o))
+    return tsvalue(o)->tsv.len;
+  else {
+    size_t l;
+    lua_lock(L);  /* `luaV_tostring' may create a new string */
+    l = (luaV_tostring(L, o) ? tsvalue(o)->tsv.len : 0);
+    lua_unlock(L);
+    return l;
+  }
 }
 
-LUA_API void *lua_touserdata (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
-  return (o == NULL || ttype(o) != LUA_TUSERDATA) ? NULL :
-                                                    tsvalue(o)->u.d.value;
+
+LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
+  return (o == NULL || !iscfunction(o)) ? NULL : clvalue(o)->c.f;
 }
 
-LUA_API const void *lua_topointer (lua_State *L, int index) {
-  StkId o = luaA_indexAcceptable(L, index);
+
+LUA_API void *lua_touserdata (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
   if (o == NULL) return NULL;
   switch (ttype(o)) {
-    case LUA_TTABLE: 
-      return hvalue(o);
-    case LUA_TFUNCTION:
-      return clvalue(o);
+    case LUA_TUSERDATA: return (uvalue(o) + 1);
+    case LUA_TLIGHTUSERDATA: return pvalue(o);
     default: return NULL;
   }
 }
 
 
+LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
+  return (o == NULL || !ttisthread(o)) ? NULL : thvalue(o);
+}
+
+
+LUA_API const void *lua_topointer (lua_State *L, int idx) {
+  StkId o = luaA_indexAcceptable(L, idx);
+  if (o == NULL) return NULL;
+  else {
+    switch (ttype(o)) {
+      case LUA_TTABLE: return hvalue(o);
+      case LUA_TFUNCTION: return clvalue(o);
+      case LUA_TTHREAD: return thvalue(o);
+      case LUA_TUSERDATA:
+      case LUA_TLIGHTUSERDATA:
+        return lua_touserdata(L, idx);
+      default: return NULL;
+    }
+  }
+}
+
+
 
 /*
 ** push functions (C -> stack)
@@ -200,22 +387,27 @@ LUA_API const void *lua_topointer (lua_State *L, int index) {
 
 
 LUA_API void lua_pushnil (lua_State *L) {
-  ttype(L->top) = LUA_TNIL;
+  lua_lock(L);
+  setnilvalue(L->top);
   api_incr_top(L);
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_pushnumber (lua_State *L, double n) {
-  nvalue(L->top) = n;
-  ttype(L->top) = LUA_TNUMBER;
+LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
+  lua_lock(L);
+  setnvalue(L->top, n);
   api_incr_top(L);
+  lua_unlock(L);
 }
 
 
 LUA_API void lua_pushlstring (lua_State *L, const char *s, size_t len) {
-  tsvalue(L->top) = luaS_newlstr(L, s, len);
-  ttype(L->top) = LUA_TSTRING;
+  lua_lock(L);
+  luaC_checkGC(L);
+  setsvalue2s(L->top, luaS_newlstr(L, s, len));
   api_incr_top(L);
+  lua_unlock(L);
 }
 
 
@@ -227,159 +419,338 @@ LUA_API void lua_pushstring (lua_State *L, const char *s) {
 }
 
 
-LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
-  luaV_Cclosure(L, fn, n);
+LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
+                                      va_list argp) {
+  const char *ret;
+  lua_lock(L);
+  luaC_checkGC(L);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  lua_unlock(L);
+  return ret;
 }
 
 
-LUA_API void lua_pushusertag (lua_State *L, void *u, int tag) {
-  /* ORDER LUA_T */
-  if (!(tag == LUA_ANYTAG || tag == LUA_TUSERDATA || validtag(tag)))
-    luaO_verror(L, "invalid tag for a userdata (%d)", tag);
-  tsvalue(L->top) = luaS_createudata(L, u, tag);
-  ttype(L->top) = LUA_TUSERDATA;
-  api_incr_top(L);
+LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
+  const char *ret;
+  va_list argp;
+  lua_lock(L);
+  luaC_checkGC(L);
+  va_start(argp, fmt);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  lua_unlock(L);
+  return ret;
 }
 
 
-
-/*
-** get functions (Lua -> stack)
-*/
+LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
+  Closure *cl;
+  lua_lock(L);
+  luaC_checkGC(L);
+  api_checknelems(L, n);
+  cl = luaF_newCclosure(L, n);
+  cl->c.f = fn;
+  L->top -= n;
+  while (n--)
+    setobj2n(&cl->c.upvalue[n], L->top+n);
+  setclvalue(L->top, cl);
+  api_incr_top(L);
+  lua_unlock(L);
+}
 
 
-LUA_API void lua_getglobal (lua_State *L, const char *name) {
-  StkId top = L->top;
-  *top = *luaV_getglobal(L, luaS_new(L, name));
-  L->top = top;
+LUA_API void lua_pushboolean (lua_State *L, int b) {
+  lua_lock(L);
+  setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
   api_incr_top(L);
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_gettable (lua_State *L, int index) {
-  StkId t = Index(L, index);
-  StkId top = L->top;
-  *(top-1) = *luaV_gettable(L, t);
-  L->top = top;  /* tag method may change top */
+LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
+  lua_lock(L);
+  setpvalue(L->top, p);
+  api_incr_top(L);
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_rawget (lua_State *L, int index) {
-  StkId t = Index(L, index);
-  LUA_ASSERT(ttype(t) == LUA_TTABLE, "table expected");
-  *(L->top - 1) = *luaH_get(L, hvalue(t), L->top - 1);
-}
 
+/*
+** get functions (Lua -> stack)
+*/
 
-LUA_API void lua_rawgeti (lua_State *L, int index, int n) {
-  StkId o = Index(L, index);
-  LUA_ASSERT(ttype(o) == LUA_TTABLE, "table expected");
-  *L->top = *luaH_getnum(hvalue(o), n);
-  api_incr_top(L);
+
+LUA_API void lua_gettable (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = luaA_index(L, idx);
+  setobj2s(L->top - 1, luaV_gettable(L, t, L->top - 1, 0));
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_getglobals (lua_State *L) {
-  hvalue(L->top) = L->gt;
-  ttype(L->top) = LUA_TTABLE;
-  api_incr_top(L);
+LUA_API void lua_rawget (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = luaA_index(L, idx);
+  api_check(L, ttistable(t));
+  setobj2s(L->top - 1, luaH_get(hvalue(t), L->top - 1));
+  lua_unlock(L);
 }
 
 
-LUA_API int lua_getref (lua_State *L, int ref) {
-  if (ref == LUA_REFNIL)
-    ttype(L->top) = LUA_TNIL;
-  else if (0 <= ref && ref < L->refSize &&
-          (L->refArray[ref].st == LOCK || L->refArray[ref].st == HOLD))
-    *L->top = L->refArray[ref].o;
-  else
-    return 0;
+LUA_API void lua_rawgeti (lua_State *L, int idx, int n) {
+  StkId o;
+  lua_lock(L);
+  o = luaA_index(L, idx);
+  api_check(L, ttistable(o));
+  setobj2s(L->top, luaH_getnum(hvalue(o), n));
   api_incr_top(L);
-  return 1;
+  lua_unlock(L);
 }
 
 
 LUA_API void lua_newtable (lua_State *L) {
-  hvalue(L->top) = luaH_new(L, 0);
-  ttype(L->top) = LUA_TTABLE;
+  lua_lock(L);
+  luaC_checkGC(L);
+  sethvalue(L->top, luaH_new(L, 0, 0));
   api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_getmetatable (lua_State *L, int objindex) {
+  const TObject *obj;
+  Table *mt = NULL;
+  int res;
+  lua_lock(L);
+  obj = luaA_indexAcceptable(L, objindex);
+  if (obj != NULL) {
+    switch (ttype(obj)) {
+      case LUA_TTABLE:
+        mt = hvalue(obj)->metatable;
+        break;
+      case LUA_TUSERDATA:
+        mt = uvalue(obj)->uv.metatable;
+        break;
+    }
+  }
+  if (mt == NULL || mt == hvalue(defaultmeta(L)))
+    res = 0;
+  else {
+    sethvalue(L->top, mt);
+    api_incr_top(L);
+    res = 1;
+  }
+  lua_unlock(L);
+  return res;
 }
 
 
+LUA_API void lua_getfenv (lua_State *L, int idx) {
+  StkId o;
+  lua_lock(L);
+  o = luaA_index(L, idx);
+  setobj2s(L->top, isLfunction(o) ? &clvalue(o)->l.g : gt(L));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
 
 /*
 ** set functions (stack -> Lua)
 */
 
 
-LUA_API void lua_setglobal (lua_State *L, const char *name) {
-  StkId top = L->top;
-  luaV_setglobal(L, luaS_new(L, name));
-  L->top = top-1;  /* remove element from the top */
+LUA_API void lua_settable (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  api_checknelems(L, 2);
+  t = luaA_index(L, idx);
+  luaV_settable(L, t, L->top - 2, L->top - 1);
+  L->top -= 2;  /* pop index and value */
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_settable (lua_State *L, int index) {
-  StkId t = Index(L, index);
-  StkId top = L->top;
-  luaV_settable(L, t, top-2);
-  L->top = top-2;  /* pop index and value */
+LUA_API void lua_rawset (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  api_checknelems(L, 2);
+  t = luaA_index(L, idx);
+  api_check(L, ttistable(t));
+  setobj2t(luaH_set(L, hvalue(t), L->top-2), L->top-1);  /* write barrier */
+  L->top -= 2;
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_rawset (lua_State *L, int index) {
-  StkId t = Index(L, index);
-  LUA_ASSERT(ttype(t) == LUA_TTABLE, "table expected");
-  *luaH_set(L, hvalue(t), L->top-2) = *(L->top-1);
-  L->top -= 2;
+LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
+  StkId o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = luaA_index(L, idx);
+  api_check(L, ttistable(o));
+  setobj2t(luaH_setnum(L, hvalue(o), n), L->top-1);  /* write barrier */
+  L->top--;
+  lua_unlock(L);
 }
 
 
-LUA_API void lua_rawseti (lua_State *L, int index, int n) {
-  StkId o = Index(L, index);
-  LUA_ASSERT(ttype(o) == LUA_TTABLE, "table expected");
-  *luaH_setint(L, hvalue(o), n) = *(L->top-1);
+LUA_API int lua_setmetatable (lua_State *L, int objindex) {
+  TObject *obj, *mt;
+  int res = 1;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  obj = luaA_index(L, objindex);
+  mt = (!ttisnil(L->top - 1)) ? L->top - 1 : defaultmeta(L);
+  api_check(L, ttistable(mt));
+  switch (ttype(obj)) {
+    case LUA_TTABLE: {
+      hvalue(obj)->metatable = hvalue(mt);  /* write barrier */
+      break;
+    }
+    case LUA_TUSERDATA: {
+      uvalue(obj)->uv.metatable = hvalue(mt);  /* write barrier */
+      break;
+    }
+    default: {
+      res = 0;  /* cannot set */
+      break;
+    }
+  }
   L->top--;
+  lua_unlock(L);
+  return res;
 }
 
 
-LUA_API void lua_setglobals (lua_State *L) {
-  StkId newtable = --L->top;
-  LUA_ASSERT(ttype(newtable) == LUA_TTABLE, "table expected");
-  L->gt = hvalue(newtable);
+LUA_API int lua_setfenv (lua_State *L, int idx) {
+  StkId o;
+  int res = 0;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = luaA_index(L, idx);
+  L->top--;
+  api_check(L, ttistable(L->top));
+  if (isLfunction(o)) {
+    res = 1;
+    clvalue(o)->l.g = *(L->top);
+  }
+  lua_unlock(L);
+  return res;
 }
 
 
-LUA_API int lua_ref (lua_State *L,  int lock) {
-  int ref;
-  if (ttype(L->top-1) == LUA_TNIL)
-    ref = LUA_REFNIL;
-  else {
-    if (L->refFree != NONEXT) {  /* is there a free place? */
-      ref = L->refFree;
-      L->refFree = L->refArray[ref].st;
-    }
-    else {  /* no more free places */
-      luaM_growvector(L, L->refArray, L->refSize, 1, struct Ref,
-                      "reference table overflow", MAX_INT);
-      L->nblocks += sizeof(struct Ref);
-      ref = L->refSize++;
-    }
-    L->refArray[ref].o = *(L->top-1);
-    L->refArray[ref].st = lock ? LOCK : HOLD;
-  }
-  L->top--;
-  return ref;
+/*
+** `load' and `call' functions (run Lua code)
+*/
+
+LUA_API void lua_call (lua_State *L, int nargs, int nresults) {
+  StkId func;
+  lua_lock(L);
+  api_checknelems(L, nargs+1);
+  func = L->top - (nargs+1);
+  luaD_call(L, func, nresults);
+  lua_unlock(L);
 }
 
 
+
 /*
-** "do" functions (run Lua code)
-** (most of them are in ldo.c)
+** Execute a protected call.
 */
+struct CallS {  /* data to `f_call' */
+  StkId func;
+  int nresults;
+};
+
 
-LUA_API void lua_rawcall (lua_State *L, int nargs, int nresults) {
-  luaD_call(L, L->top-(nargs+1), nresults);
+static void f_call (lua_State *L, void *ud) {
+  struct CallS *c = cast(struct CallS *, ud);
+  luaD_call(L, c->func, c->nresults);
+}
+
+
+
+LUA_API int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc) {
+  struct CallS c;
+  int status;
+  ptrdiff_t func;
+  lua_lock(L);
+  func = (errfunc == 0) ? 0 : savestack(L, luaA_index(L, errfunc));
+  c.func = L->top - (nargs+1);  /* function to be called */
+  c.nresults = nresults;
+  status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+  lua_unlock(L);
+  return status;
+}
+
+
+/*
+** Execute a protected C call.
+*/
+struct CCallS {  /* data to `f_Ccall' */
+  lua_CFunction func;
+  void *ud;
+};
+
+
+static void f_Ccall (lua_State *L, void *ud) {
+  struct CCallS *c = cast(struct CCallS *, ud);
+  Closure *cl;
+  cl = luaF_newCclosure(L, 0);
+  cl->c.f = c->func;
+  setclvalue(L->top, cl);  /* push function */
+  incr_top(L);
+  setpvalue(L->top, c->ud);  /* push only argument */
+  incr_top(L);
+  luaD_call(L, L->top - 2, 0);
+}
+
+
+LUA_API int lua_cpcall (lua_State *L, lua_CFunction func, void *ud) {
+  struct CCallS c;
+  int status;
+  lua_lock(L);
+  c.func = func;
+  c.ud = ud;
+  status = luaD_pcall(L, f_Ccall, &c, savestack(L, L->top), 0);
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_load (lua_State *L, lua_Chunkreader reader, void *data,
+                      const char *chunkname) {
+  ZIO z;
+  int status;
+  int c;
+  lua_lock(L);
+  if (!chunkname) chunkname = "?";
+  luaZ_init(&z, reader, data, chunkname);
+  c = luaZ_lookahead(&z);
+  status = luaD_protectedparser(L, &z, (c == LUA_SIGNATURE[0]));
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_dump (lua_State *L, lua_Chunkwriter writer, void *data) {
+  int status;
+  TObject *o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = L->top - 1;
+  if (isLfunction(o) && clvalue(o)->l.nupvalues == 0) {
+    luaU_dump(L, clvalue(o)->l.p, writer, data);
+    status = 1;
+  }
+  else
+    status = 0;
+  lua_unlock(L);
+  return status;
 }
 
 
@@ -388,23 +759,34 @@ LUA_API void lua_rawcall (lua_State *L, int nargs, int nresults) {
 */
 
 /* GC values are expressed in Kbytes: #bytes/2^10 */
-#define GCscale(x)		((int)((x)>>10))
-#define GCunscale(x)		((unsigned long)(x)<<10)
+#define GCscalel(x)		((x)>>10)
+#define GCscale(x)		(cast(int, GCscalel(x)))
+#define GCunscale(x)		(cast(lu_mem, x)<<10)
 
 LUA_API int lua_getgcthreshold (lua_State *L) {
-  return GCscale(L->GCthreshold);
+  int threshold;
+  lua_lock(L);
+  threshold = GCscale(G(L)->GCthreshold);
+  lua_unlock(L);
+  return threshold;
 }
 
 LUA_API int lua_getgccount (lua_State *L) {
-  return GCscale(L->nblocks);
+  int count;
+  lua_lock(L);
+  count = GCscale(G(L)->nblocks);
+  lua_unlock(L);
+  return count;
 }
 
 LUA_API void lua_setgcthreshold (lua_State *L, int newthreshold) {
-  if (newthreshold > GCscale(ULONG_MAX))
-    L->GCthreshold = ULONG_MAX;
+  lua_lock(L);
+  if (cast(lu_mem, newthreshold) > GCscalel(MAX_LUMEM))
+    G(L)->GCthreshold = MAX_LUMEM;
   else
-    L->GCthreshold = GCunscale(newthreshold);
+    G(L)->GCthreshold = GCunscale(newthreshold);
   luaC_checkGC(L);
+  lua_unlock(L);
 }
 
 
@@ -412,83 +794,129 @@ LUA_API void lua_setgcthreshold (lua_State *L, int newthreshold) {
 ** miscellaneous functions
 */
 
-LUA_API void lua_settag (lua_State *L, int tag) {
-  luaT_realtag(L, tag);
-  switch (ttype(L->top-1)) {
-    case LUA_TTABLE:
-      hvalue(L->top-1)->htag = tag;
-      break;
-    case LUA_TUSERDATA:
-      tsvalue(L->top-1)->u.d.tag = tag;
-      break;
-    default:
-      luaO_verror(L, "cannot change the tag of a %.20s",
-                  luaO_typename(L->top-1));
-  }
+
+LUA_API const char *lua_version (void) {
+  return LUA_VERSION;
 }
 
 
-LUA_API void lua_unref (lua_State *L, int ref) {
-  if (ref >= 0) {
-    LUA_ASSERT(ref < L->refSize && L->refArray[ref].st < 0, "invalid ref");
-    L->refArray[ref].st = L->refFree;
-    L->refFree = ref;
-  }
+LUA_API int lua_error (lua_State *L) {
+  lua_lock(L);
+  api_checknelems(L, 1);
+  luaG_errormsg(L);
+  lua_unlock(L);
+  return 0;  /* to avoid warnings */
 }
 
 
-LUA_API int lua_next (lua_State *L, int index) {
-  StkId t = luaA_index(L, index);
-  Node *n;
-  LUA_ASSERT(ttype(t) == LUA_TTABLE, "table expected");
-  n = luaH_next(L, hvalue(t), luaA_index(L, -1));
-  if (n) {
-    *(L->top-1) = *key(n);
-    *L->top = *val(n);
+LUA_API int lua_next (lua_State *L, int idx) {
+  StkId t;
+  int more;
+  lua_lock(L);
+  t = luaA_index(L, idx);
+  api_check(L, ttistable(t));
+  more = luaH_next(L, hvalue(t), L->top - 1);
+  if (more) {
     api_incr_top(L);
-    return 1;
   }
-  else {  /* no more elements */
+  else  /* no more elements */
     L->top -= 1;  /* remove key */
-    return 0;
+  lua_unlock(L);
+  return more;
+}
+
+
+LUA_API void lua_concat (lua_State *L, int n) {
+  lua_lock(L);
+  luaC_checkGC(L);
+  api_checknelems(L, n);
+  if (n >= 2) {
+    luaV_concat(L, n, L->top - L->base - 1);
+    L->top -= (n-1);
+  }
+  else if (n == 0) {  /* push empty string */
+    setsvalue2s(L->top, luaS_newlstr(L, NULL, 0));
+    api_incr_top(L);
+  }
+  /* else n == 1; nothing to do */
+  lua_unlock(L);
+}
+
+
+LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
+  Udata *u;
+  lua_lock(L);
+  luaC_checkGC(L);
+  u = luaS_newudata(L, size);
+  setuvalue(L->top, u);
+  api_incr_top(L);
+  lua_unlock(L);
+  return u + 1;
+}
+
+
+LUA_API int lua_pushupvalues (lua_State *L) {
+  Closure *func;
+  int n, i;
+  lua_lock(L);
+  api_check(L, iscfunction(L->base - 1));
+  func = clvalue(L->base - 1);
+  n = func->c.nupvalues;
+  luaD_checkstack(L, n + LUA_MINSTACK);
+  for (i=0; i<n; i++) {
+    setobj2s(L->top, &func->c.upvalue[i]);
+    L->top++;
   }
+  lua_unlock(L);
+  return n;
 }
 
 
-LUA_API int lua_getn (lua_State *L, int index) {
-  Hash *h = hvalue(luaA_index(L, index));
-  const TObject *value = luaH_getstr(h, luaS_new(L, "n"));  /* value = h.n */
-  if (ttype(value) == LUA_TNUMBER)
-    return (int)nvalue(value);
+static const char *aux_upvalue (lua_State *L, int funcindex, int n,
+                                TObject **val) {
+  Closure *f;
+  StkId fi = luaA_index(L, funcindex);
+  if (!ttisfunction(fi)) return NULL;
+  f = clvalue(fi);
+  if (f->c.isC) {
+    if (n > f->c.nupvalues) return NULL;
+    *val = &f->c.upvalue[n-1];
+    return "";
+  }
   else {
-    Number max = 0;
-    int i = h->size;
-    Node *n = h->node;
-    while (i--) {
-      if (ttype(key(n)) == LUA_TNUMBER &&
-          ttype(val(n)) != LUA_TNIL &&
-          nvalue(key(n)) > max)
-        max = nvalue(key(n));
-      n++;
-    }
-    return (int)max;
+    Proto *p = f->l.p;
+    if (n > p->sizeupvalues) return NULL;
+    *val = f->l.upvals[n-1]->v;
+    return getstr(p->upvalues[n-1]);
   }
 }
 
 
-LUA_API void lua_concat (lua_State *L, int n) {
-  StkId top = L->top;
-  luaV_strconc(L, n, top);
-  L->top = top-(n-1);
-  luaC_checkGC(L);
+LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TObject *val;
+  lua_lock(L);
+  name = aux_upvalue(L, funcindex, n, &val);
+  if (name) {
+    setobj2s(L->top, val);
+    api_incr_top(L);
+  }
+  lua_unlock(L);
+  return name;
 }
 
 
-LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
-  TString *ts = luaS_newudata(L, (size==0) ? 1 : size, NULL);
-  tsvalue(L->top) = ts;
-  ttype(L->top) = LUA_TUSERDATA;
-  api_incr_top(L);
-  return ts->u.d.value;
+LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TObject *val;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  name = aux_upvalue(L, funcindex, n, &val);
+  if (name) {
+    L->top--;
+    setobj(val, L->top);  /* write barrier */
+  }
+  lua_unlock(L);
+  return name;
 }
 
diff --git a/src/lapi.h b/src/lapi.h
index 5cefdc7a..d12612f3 100644
--- a/src/lapi.h
+++ b/src/lapi.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.h,v 1.20 2000/08/31 14:08:27 roberto Exp $
+** $Id: lapi.h,v 1.21 2002/03/04 21:29:41 roberto Exp $
 ** Auxiliary functions from Lua API
 ** See Copyright Notice in lua.h
 */
@@ -11,7 +11,6 @@
 #include "lobject.h"
 
 
-TObject *luaA_index (lua_State *L, int index);
 void luaA_pushobject (lua_State *L, const TObject *o);
 
 #endif
diff --git a/src/lcode.c b/src/lcode.c
index 6882240d..d626ecd6 100644
--- a/src/lcode.c
+++ b/src/lcode.c
@@ -1,66 +1,84 @@
 /*
-** $Id: lcode.c,v 1.51 2000/09/29 12:42:13 roberto Exp $
+** $Id: lcode.c,v 1.117 2003/04/03 13:35:34 roberto Exp $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
 
 
-#include "stdlib.h"
+#include <stdlib.h>
+
+#define lcode_c
 
 #include "lua.h"
 
 #include "lcode.h"
+#include "ldebug.h"
 #include "ldo.h"
 #include "llex.h"
 #include "lmem.h"
 #include "lobject.h"
 #include "lopcodes.h"
 #include "lparser.h"
+#include "ltable.h"
 
 
-void luaK_error (LexState *ls, const char *msg) {
-  luaX_error(ls, msg, ls->t.token);
-}
+#define hasjumps(e)	((e)->t != (e)->f)
 
 
-/*
-** Returns the the previous instruction, for optimizations.
-** If there is a jump target between this and the current instruction,
-** returns a dummy instruction to avoid wrong optimizations.
-*/
-static Instruction previous_instruction (FuncState *fs) {
-  if (fs->pc > fs->lasttarget)  /* no jumps to current position? */
-    return fs->f->code[fs->pc-1];  /* returns previous instruction */
-  else
-    return CREATE_0(OP_END);  /* no optimizations after an `END' */
+void luaK_nil (FuncState *fs, int from, int n) {
+  Instruction *previous;
+  if (fs->pc > fs->lasttarget &&  /* no jumps to current position? */
+      GET_OPCODE(*(previous = &fs->f->code[fs->pc-1])) == OP_LOADNIL) {
+    int pfrom = GETARG_A(*previous);
+    int pto = GETARG_B(*previous);
+    if (pfrom <= from && from <= pto+1) {  /* can connect both? */
+      if (from+n-1 > pto)
+        SETARG_B(*previous, from+n-1);
+      return;
+    }
+  }
+  luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0);  /* else no optimization */
 }
 
 
 int luaK_jump (FuncState *fs) {
-  int j = luaK_code1(fs, OP_JMP, NO_JUMP);
-  if (j == fs->lasttarget) {  /* possible jumps to this jump? */
-    luaK_concat(fs, &j, fs->jlt);  /* keep them on hold */
-    fs->jlt = NO_JUMP;
-  }
+  int jpc = fs->jpc;  /* save list of jumps to here */
+  int j;
+  fs->jpc = NO_JUMP;
+  j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
+  luaK_concat(fs, &j, jpc);  /* keep them on hold */
   return j;
 }
 
 
+static int luaK_condjump (FuncState *fs, OpCode op, int A, int B, int C) {
+  luaK_codeABC(fs, op, A, B, C);
+  return luaK_jump(fs);
+}
+
+
 static void luaK_fixjump (FuncState *fs, int pc, int dest) {
   Instruction *jmp = &fs->f->code[pc];
-  if (dest == NO_JUMP)
-    SETARG_S(*jmp, NO_JUMP);  /* point to itself to represent end of list */
-  else {  /* jump is relative to position following jump instruction */
-    int offset = dest-(pc+1);
-    if (abs(offset) > MAXARG_S)
-      luaK_error(fs->ls, "control structure too long");
-    SETARG_S(*jmp, offset);
-  }
+  int offset = dest-(pc+1);
+  lua_assert(dest != NO_JUMP);
+  if (abs(offset) > MAXARG_sBx)
+    luaX_syntaxerror(fs->ls, "control structure too long");
+  SETARG_sBx(*jmp, offset);
+}
+
+
+/*
+** returns current `pc' and marks it as a jump target (to avoid wrong
+** optimizations with consecutive instructions not in the same basic block).
+*/
+int luaK_getlabel (FuncState *fs) {
+  fs->lasttarget = fs->pc;
+  return fs->pc;
 }
 
 
 static int luaK_getjump (FuncState *fs, int pc) {
-  int offset = GETARG_S(fs->f->code[pc]);
+  int offset = GETARG_sBx(fs->f->code[pc]);
   if (offset == NO_JUMP)  /* point to itself represents end of list */
     return NO_JUMP;  /* end of list */
   else
@@ -68,634 +86,629 @@ static int luaK_getjump (FuncState *fs, int pc) {
 }
 
 
+static Instruction *getjumpcontrol (FuncState *fs, int pc) {
+  Instruction *pi = &fs->f->code[pc];
+  if (pc >= 1 && testOpMode(GET_OPCODE(*(pi-1)), OpModeT))
+    return pi-1;
+  else
+    return pi;
+}
+
+
 /*
-** returns current `pc' and marks it as a jump target (to avoid wrong
-** optimizations with consecutive instructions not in the same basic block).
-** discharge list of jumps to last target.
+** check whether list has any jump that do not produce a value
+** (or produce an inverted value)
 */
-int luaK_getlabel (FuncState *fs) {
-  if (fs->pc != fs->lasttarget) {
-    int lasttarget = fs->lasttarget;
-    fs->lasttarget = fs->pc;
-    luaK_patchlist(fs, fs->jlt, lasttarget);  /* discharge old list `jlt' */
-    fs->jlt = NO_JUMP;  /* nobody jumps to this new label (yet) */
+static int need_value (FuncState *fs, int list, int cond) {
+  for (; list != NO_JUMP; list = luaK_getjump(fs, list)) {
+    Instruction i = *getjumpcontrol(fs, list);
+    if (GET_OPCODE(i) != OP_TEST || GETARG_C(i) != cond) return 1;
   }
-  return fs->pc;
+  return 0;  /* not found */
 }
 
 
-void luaK_deltastack (FuncState *fs, int delta) {
-  fs->stacklevel += delta;
-  if (fs->stacklevel > fs->f->maxstacksize) {
-    if (fs->stacklevel > MAXSTACK)
-      luaK_error(fs->ls, "function or expression too complex");
-    fs->f->maxstacksize = fs->stacklevel;
-  }
+static void patchtestreg (Instruction *i, int reg) {
+  if (reg == NO_REG) reg = GETARG_B(*i);
+  SETARG_A(*i, reg);
 }
 
 
-void luaK_kstr (LexState *ls, int c) {
-  luaK_code1(ls->fs, OP_PUSHSTRING, c);
+static void luaK_patchlistaux (FuncState *fs, int list,
+          int ttarget, int treg, int ftarget, int freg, int dtarget) {
+  while (list != NO_JUMP) {
+    int next = luaK_getjump(fs, list);
+    Instruction *i = getjumpcontrol(fs, list);
+    if (GET_OPCODE(*i) != OP_TEST) {
+      lua_assert(dtarget != NO_JUMP);
+      luaK_fixjump(fs, list, dtarget);  /* jump to default target */
+    }
+    else {
+      if (GETARG_C(*i)) {
+        lua_assert(ttarget != NO_JUMP);
+        patchtestreg(i, treg);
+        luaK_fixjump(fs, list, ttarget);
+      }
+      else {
+        lua_assert(ftarget != NO_JUMP);
+        patchtestreg(i, freg);
+        luaK_fixjump(fs, list, ftarget);
+      }
+    }
+    list = next;
+  }
 }
 
 
-static int number_constant (FuncState *fs, Number r) {
-  /* check whether `r' has appeared within the last LOOKBACKNUMS entries */
-  Proto *f = fs->f;
-  int c = f->nknum;
-  int lim = c < LOOKBACKNUMS ? 0 : c-LOOKBACKNUMS;
-  while (--c >= lim)
-    if (f->knum[c] == r) return c;
-  /* not found; create a new entry */
-  luaM_growvector(fs->L, f->knum, f->nknum, 1, Number,
-                  "constant table overflow", MAXARG_U);
-  c = f->nknum++;
-  f->knum[c] = r;
-  return c;
-}
-
-
-void luaK_number (FuncState *fs, Number f) {
-  if (f <= (Number)MAXARG_S && (Number)(int)f == f)
-    luaK_code1(fs, OP_PUSHINT, (int)f);  /* f has a short integer value */
-  else
-    luaK_code1(fs, OP_PUSHNUM, number_constant(fs, f));
+static void luaK_dischargejpc (FuncState *fs) {
+  luaK_patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc, NO_REG, fs->pc);
+  fs->jpc = NO_JUMP;
 }
 
 
-void luaK_adjuststack (FuncState *fs, int n) {
-  if (n > 0)
-    luaK_code1(fs, OP_POP, n);
-  else
-    luaK_code1(fs, OP_PUSHNIL, -n);
+void luaK_patchlist (FuncState *fs, int list, int target) {
+  if (target == fs->pc)
+    luaK_patchtohere(fs, list);
+  else {
+    lua_assert(target < fs->pc);
+    luaK_patchlistaux(fs, list, target, NO_REG, target, NO_REG, target);
+  }
 }
 
 
-int luaK_lastisopen (FuncState *fs) {
-  /* check whether last instruction is an open function call */
-  Instruction i = previous_instruction(fs);
-  if (GET_OPCODE(i) == OP_CALL && GETARG_B(i) == MULT_RET)
-    return 1;
-  else return 0;
+void luaK_patchtohere (FuncState *fs, int list) {
+  luaK_getlabel(fs);
+  luaK_concat(fs, &fs->jpc, list);
 }
 
 
-void luaK_setcallreturns (FuncState *fs, int nresults) {
-  if (luaK_lastisopen(fs)) {  /* expression is an open function call? */
-    SETARG_B(fs->f->code[fs->pc-1], nresults);  /* set number of results */
-    luaK_deltastack(fs, nresults);  /* push results */
+void luaK_concat (FuncState *fs, int *l1, int l2) {
+  if (l2 == NO_JUMP) return;
+  else if (*l1 == NO_JUMP)
+    *l1 = l2;
+  else {
+    int list = *l1;
+    int next;
+    while ((next = luaK_getjump(fs, list)) != NO_JUMP)  /* find last element */
+      list = next;
+    luaK_fixjump(fs, list, l2);
   }
 }
 
 
-static int discharge (FuncState *fs, expdesc *var) {
-  switch (var->k) {
-    case VLOCAL:
-      luaK_code1(fs, OP_GETLOCAL, var->u.index);
-      break;
-    case VGLOBAL:
-      luaK_code1(fs, OP_GETGLOBAL, var->u.index);
-      break;
-    case VINDEXED:
-      luaK_code0(fs, OP_GETTABLE);
-      break;
-    case VEXP:
-      return 0;  /* nothing to do */
+void luaK_checkstack (FuncState *fs, int n) {
+  int newstack = fs->freereg + n;
+  if (newstack > fs->f->maxstacksize) {
+    if (newstack >= MAXSTACK)
+      luaX_syntaxerror(fs->ls, "function or expression too complex");
+    fs->f->maxstacksize = cast(lu_byte, newstack);
   }
-  var->k = VEXP;
-  var->u.l.t = var->u.l.f = NO_JUMP;
-  return 1;
 }
 
 
-static void discharge1 (FuncState *fs, expdesc *var) {
-  discharge(fs, var);
- /* if it has jumps then it is already discharged */
-  if (var->u.l.t == NO_JUMP && var->u.l.f  == NO_JUMP)
-    luaK_setcallreturns(fs, 1);  /* call must return 1 value */
+void luaK_reserveregs (FuncState *fs, int n) {
+  luaK_checkstack(fs, n);
+  fs->freereg += n;
 }
 
 
-void luaK_storevar (LexState *ls, const expdesc *var) {
-  FuncState *fs = ls->fs;
-  switch (var->k) {
-    case VLOCAL:
-      luaK_code1(fs, OP_SETLOCAL, var->u.index);
-      break;
-    case VGLOBAL:
-      luaK_code1(fs, OP_SETGLOBAL, var->u.index);
-      break;
-    case VINDEXED:  /* table is at top-3; pop 3 elements after operation */
-      luaK_code2(fs, OP_SETTABLE, 3, 3);
-      break;
-    default:
-      LUA_INTERNALERROR("invalid var kind to store");
+static void freereg (FuncState *fs, int reg) {
+  if (reg >= fs->nactvar && reg < MAXSTACK) {
+    fs->freereg--;
+    lua_assert(reg == fs->freereg);
   }
 }
 
 
-static OpCode invertjump (OpCode op) {
-  switch (op) {
-    case OP_JMPNE: return OP_JMPEQ;
-    case OP_JMPEQ: return OP_JMPNE;
-    case OP_JMPLT: return OP_JMPGE;
-    case OP_JMPLE: return OP_JMPGT;
-    case OP_JMPGT: return OP_JMPLE;
-    case OP_JMPGE: return OP_JMPLT;
-    case OP_JMPT: case OP_JMPONT:  return OP_JMPF;
-    case OP_JMPF: case OP_JMPONF:  return OP_JMPT;
-    default:
-      LUA_INTERNALERROR("invalid jump instruction");
-      return OP_END;  /* to avoid warnings */
-  }
+static void freeexp (FuncState *fs, expdesc *e) {
+  if (e->k == VNONRELOC)
+    freereg(fs, e->info);
 }
 
 
-static void luaK_patchlistaux (FuncState *fs, int list, int target,
-                               OpCode special, int special_target) {
-  Instruction *code = fs->f->code;
-  while (list != NO_JUMP) {
-    int next = luaK_getjump(fs, list);
-    Instruction *i = &code[list];
-    OpCode op = GET_OPCODE(*i);
-    if (op == special)  /* this `op' already has a value */
-      luaK_fixjump(fs, list, special_target);
-    else {
-      luaK_fixjump(fs, list, target);  /* do the patch */
-      if (op == OP_JMPONT)  /* remove eventual values */
-        SET_OPCODE(*i, OP_JMPT);
-      else if (op == OP_JMPONF)
-        SET_OPCODE(*i, OP_JMPF);
-    }
-    list = next;
+static int addk (FuncState *fs, TObject *k, TObject *v) {
+  const TObject *idx = luaH_get(fs->h, k);
+  if (ttisnumber(idx)) {
+    lua_assert(luaO_rawequalObj(&fs->f->k[cast(int, nvalue(idx))], v));
+    return cast(int, nvalue(idx));
+  }
+  else {  /* constant not found; create a new entry */
+    Proto *f = fs->f;
+    luaM_growvector(fs->L, f->k, fs->nk, f->sizek, TObject,
+                    MAXARG_Bx, "constant table overflow");
+    setobj2n(&f->k[fs->nk], v);
+    setnvalue(luaH_set(fs->L, fs->h, k), cast(lua_Number, fs->nk));
+    return fs->nk++;
   }
 }
 
 
-void luaK_patchlist (FuncState *fs, int list, int target) {
-  if (target == fs->lasttarget)  /* same target that list `jlt'? */
-    luaK_concat(fs, &fs->jlt, list);  /* delay fixing */
-  else
-    luaK_patchlistaux(fs, list, target, OP_END, 0);
+int luaK_stringK (FuncState *fs, TString *s) {
+  TObject o;
+  setsvalue(&o, s);
+  return addk(fs, &o, &o);
 }
 
 
-static int need_value (FuncState *fs, int list, OpCode hasvalue) {
-  /* check whether list has a jump without a value */
-  for (; list != NO_JUMP; list = luaK_getjump(fs, list))
-    if (GET_OPCODE(fs->f->code[list]) != hasvalue) return 1;
-  return 0;  /* not found */
+int luaK_numberK (FuncState *fs, lua_Number r) {
+  TObject o;
+  setnvalue(&o, r);
+  return addk(fs, &o, &o);
 }
 
 
-void luaK_concat (FuncState *fs, int *l1, int l2) {
-  if (*l1 == NO_JUMP)
-    *l1 = l2;
-  else {
-    int list = *l1;
-    for (;;) {  /* traverse `l1' */
-      int next = luaK_getjump(fs, list);
-      if (next == NO_JUMP) {  /* end of list? */
-        luaK_fixjump(fs, list, l2);
-        return;
-      }
-      list = next;
-    }
-  }
+static int nil_constant (FuncState *fs) {
+  TObject k, v;
+  setnilvalue(&v);
+  sethvalue(&k, fs->h);  /* cannot use nil as key; instead use table itself */
+  return addk(fs, &k, &v);
 }
 
 
-static void luaK_testgo (FuncState *fs, expdesc *v, int invert, OpCode jump) {
-  int prevpos;  /* position of last instruction */
-  Instruction *previous;
-  int *golist, *exitlist;
-  if (!invert) {
-    golist = &v->u.l.f;    /* go if false */
-    exitlist = &v->u.l.t;  /* exit if true */
-  }
-  else {
-    golist = &v->u.l.t;    /* go if true */
-    exitlist = &v->u.l.f;  /* exit if false */
-  }
-  discharge1(fs, v);
-  prevpos = fs->pc-1;
-  previous = &fs->f->code[prevpos];
-  LUA_ASSERT(*previous==previous_instruction(fs), "no jump allowed here");
-  if (!ISJUMP(GET_OPCODE(*previous)))
-    prevpos = luaK_code1(fs, jump, NO_JUMP);
-  else {  /* last instruction is already a jump */
-    if (invert)
-      SET_OPCODE(*previous, invertjump(GET_OPCODE(*previous)));
+void luaK_setcallreturns (FuncState *fs, expdesc *e, int nresults) {
+  if (e->k == VCALL) {  /* expression is an open function call? */
+    SETARG_C(getcode(fs, e), nresults+1);
+    if (nresults == 1) {  /* `regular' expression? */
+      e->k = VNONRELOC;
+      e->info = GETARG_A(getcode(fs, e));
+    }
   }
-  luaK_concat(fs, exitlist, prevpos);  /* insert last jump in `exitlist' */
-  luaK_patchlist(fs, *golist, luaK_getlabel(fs));
-  *golist = NO_JUMP;
 }
 
 
-void luaK_goiftrue (FuncState *fs, expdesc *v, int keepvalue) {
-  luaK_testgo(fs, v, 1, keepvalue ? OP_JMPONF : OP_JMPF);
+void luaK_dischargevars (FuncState *fs, expdesc *e) {
+  switch (e->k) {
+    case VLOCAL: {
+      e->k = VNONRELOC;
+      break;
+    }
+    case VUPVAL: {
+      e->info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->info, 0);
+      e->k = VRELOCABLE;
+      break;
+    }
+    case VGLOBAL: {
+      e->info = luaK_codeABx(fs, OP_GETGLOBAL, 0, e->info);
+      e->k = VRELOCABLE;
+      break;
+    }
+    case VINDEXED: {
+      freereg(fs, e->aux);
+      freereg(fs, e->info);
+      e->info = luaK_codeABC(fs, OP_GETTABLE, 0, e->info, e->aux);
+      e->k = VRELOCABLE;
+      break;
+    }
+    case VCALL: {
+      luaK_setcallreturns(fs, e, 1);
+      break;
+    }
+    default: break;  /* there is one value available (somewhere) */
+  }
 }
 
 
-static void luaK_goiffalse (FuncState *fs, expdesc *v, int keepvalue) {
-  luaK_testgo(fs, v, 0, keepvalue ? OP_JMPONT : OP_JMPT);
+static int code_label (FuncState *fs, int A, int b, int jump) {
+  luaK_getlabel(fs);  /* those instructions may be jump targets */
+  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
 }
 
 
-static int code_label (FuncState *fs, OpCode op, int arg) {
-  luaK_getlabel(fs);  /* those instructions may be jump targets */
-  return luaK_code1(fs, op, arg);
-}
-
-
-void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
-  FuncState *fs = ls->fs;
-  if (!discharge(fs, v)) {  /* `v' is an expression? */
-    OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]);
-    if (!ISJUMP(previous) && v->u.l.f == NO_JUMP && v->u.l.t == NO_JUMP) {
-      /* expression has no jumps */
-      if (onlyone)
-        luaK_setcallreturns(fs, 1);  /* call must return 1 value */
-    }
-    else {  /* expression has jumps */
-      int final;  /* position after whole expression */
-      int j = NO_JUMP;  /*  eventual  jump over values */
-      int p_nil = NO_JUMP;  /* position of an eventual PUSHNIL */
-      int p_1 = NO_JUMP;  /* position of an eventual PUSHINT */
-      if (ISJUMP(previous) || need_value(fs, v->u.l.f, OP_JMPONF)
-                           || need_value(fs, v->u.l.t, OP_JMPONT)) {
-        /* expression needs values */
-        if (ISJUMP(previous))
-          luaK_concat(fs, &v->u.l.t, fs->pc-1);  /* put `previous' in t. list */
-        else {
-          j = code_label(fs, OP_JMP, NO_JUMP);  /* to jump over both pushes */
-          /* correct stack for compiler and symbolic execution */
-          luaK_adjuststack(fs, 1);
-        }
-        p_nil = code_label(fs, OP_PUSHNILJMP, 0);
-        p_1 = code_label(fs, OP_PUSHINT, 1);
-        luaK_patchlist(fs, j, luaK_getlabel(fs));
-      }
-      final = luaK_getlabel(fs);
-      luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final);
-      luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final);
-      v->u.l.f = v->u.l.t = NO_JUMP;
+static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VNIL: {
+      luaK_nil(fs, reg, 1);
+      break;
+    }
+    case VFALSE:  case VTRUE: {
+      luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
+      break;
+    }
+    case VK: {
+      luaK_codeABx(fs, OP_LOADK, reg, e->info);
+      break;
+    }
+    case VRELOCABLE: {
+      Instruction *pc = &getcode(fs, e);
+      SETARG_A(*pc, reg);
+      break;
+    }
+    case VNONRELOC: {
+      if (reg != e->info)
+        luaK_codeABC(fs, OP_MOVE, reg, e->info, 0);
+      break;
+    }
+    default: {
+      lua_assert(e->k == VVOID || e->k == VJMP);
+      return;  /* nothing to do... */
     }
   }
+  e->info = reg;
+  e->k = VNONRELOC;
 }
 
 
-void luaK_prefix (LexState *ls, UnOpr op, expdesc *v) {
-  FuncState *fs = ls->fs;
-  if (op == OPR_MINUS) {
-    luaK_tostack(ls, v, 1);
-    luaK_code0(fs, OP_MINUS);
+static void discharge2anyreg (FuncState *fs, expdesc *e) {
+  if (e->k != VNONRELOC) {
+    luaK_reserveregs(fs, 1);
+    discharge2reg(fs, e, fs->freereg-1);
   }
-  else {  /* op == NOT */
-    Instruction *previous;
-    discharge1(fs, v);
-    previous = &fs->f->code[fs->pc-1];
-    if (ISJUMP(GET_OPCODE(*previous)))
-      SET_OPCODE(*previous, invertjump(GET_OPCODE(*previous)));
-    else
-      luaK_code0(fs, OP_NOT);
-    /* interchange true and false lists */
-    { int temp = v->u.l.f; v->u.l.f = v->u.l.t; v->u.l.t = temp; }
+}
+
+
+static void luaK_exp2reg (FuncState *fs, expdesc *e, int reg) {
+  discharge2reg(fs, e, reg);
+  if (e->k == VJMP)
+    luaK_concat(fs, &e->t, e->info);  /* put this jump in `t' list */
+  if (hasjumps(e)) {
+    int final;  /* position after whole expression */
+    int p_f = NO_JUMP;  /* position of an eventual LOAD false */
+    int p_t = NO_JUMP;  /* position of an eventual LOAD true */
+    if (need_value(fs, e->t, 1) || need_value(fs, e->f, 0)) {
+      int fj = NO_JUMP;  /* first jump (over LOAD ops.) */
+      if (e->k != VJMP)
+        fj = luaK_jump(fs);
+      p_f = code_label(fs, reg, 0, 1);
+      p_t = code_label(fs, reg, 1, 0);
+      luaK_patchtohere(fs, fj);
+    }
+    final = luaK_getlabel(fs);
+    luaK_patchlistaux(fs, e->f, p_f, NO_REG, final, reg, p_f);
+    luaK_patchlistaux(fs, e->t, final, reg, p_t, NO_REG, p_t);
   }
+  e->f = e->t = NO_JUMP;
+  e->info = reg;
+  e->k = VNONRELOC;
 }
 
 
-void luaK_infix (LexState *ls, BinOpr op, expdesc *v) {
-  FuncState *fs = ls->fs;
-  switch (op) {
-    case OPR_AND:
-      luaK_goiftrue(fs, v, 1);
-      break;
-    case OPR_OR:
-      luaK_goiffalse(fs, v, 1);
-      break;
-    default:
-      luaK_tostack(ls, v, 1);  /* all other binary operators need a value */
+void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  freeexp(fs, e);
+  luaK_reserveregs(fs, 1);
+  luaK_exp2reg(fs, e, fs->freereg - 1);
+}
+
+
+int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  if (e->k == VNONRELOC) {
+    if (!hasjumps(e)) return e->info;  /* exp is already in a register */ 
+    if (e->info >= fs->nactvar) {  /* reg. is not a local? */
+      luaK_exp2reg(fs, e, e->info);  /* put value on it */
+      return e->info;
+    }
   }
+  luaK_exp2nextreg(fs, e);  /* default */
+  return e->info;
 }
 
 
+void luaK_exp2val (FuncState *fs, expdesc *e) {
+  if (hasjumps(e))
+    luaK_exp2anyreg(fs, e);
+  else
+    luaK_dischargevars(fs, e);
+}
 
-static const struct {
-  OpCode opcode;  /* opcode for each binary operator */
-  int arg;        /* default argument for the opcode */
-} codes[] = {  /* ORDER OPR */
-      {OP_ADD, 0}, {OP_SUB, 0}, {OP_MULT, 0}, {OP_DIV, 0},
-      {OP_POW, 0}, {OP_CONCAT, 2},
-      {OP_JMPNE, NO_JUMP}, {OP_JMPEQ, NO_JUMP},
-      {OP_JMPLT, NO_JUMP}, {OP_JMPLE, NO_JUMP},
-      {OP_JMPGT, NO_JUMP}, {OP_JMPGE, NO_JUMP}
-};
 
+int luaK_exp2RK (FuncState *fs, expdesc *e) {
+  luaK_exp2val(fs, e);
+  switch (e->k) {
+    case VNIL: {
+      if (fs->nk + MAXSTACK <= MAXARG_C) {  /* constant fit in argC? */
+        e->info = nil_constant(fs);
+        e->k = VK;
+        return e->info + MAXSTACK;
+      }
+      else break;
+    }
+    case VK: {
+      if (e->info + MAXSTACK <= MAXARG_C)  /* constant fit in argC? */
+        return e->info + MAXSTACK;
+      else break;
+    }
+    default: break;
+  }
+  /* not a constant in the right range: put it in a register */
+  return luaK_exp2anyreg(fs, e);
+}
 
-void luaK_posfix (LexState *ls, BinOpr op, expdesc *v1, expdesc *v2) {
-  FuncState *fs = ls->fs;
-  switch (op) {
-    case OPR_AND: {
-      LUA_ASSERT(v1->u.l.t == NO_JUMP, "list must be closed");
-      discharge1(fs, v2);
-      v1->u.l.t = v2->u.l.t;
-      luaK_concat(fs, &v1->u.l.f, v2->u.l.f);
+
+void luaK_storevar (FuncState *fs, expdesc *var, expdesc *exp) {
+  switch (var->k) {
+    case VLOCAL: {
+      freeexp(fs, exp);
+      luaK_exp2reg(fs, exp, var->info);
+      return;
+    }
+    case VUPVAL: {
+      int e = luaK_exp2anyreg(fs, exp);
+      luaK_codeABC(fs, OP_SETUPVAL, e, var->info, 0);
       break;
     }
-    case OPR_OR: {
-      LUA_ASSERT(v1->u.l.f == NO_JUMP, "list must be closed");
-      discharge1(fs, v2);
-      v1->u.l.f = v2->u.l.f;
-      luaK_concat(fs, &v1->u.l.t, v2->u.l.t);
+    case VGLOBAL: {
+      int e = luaK_exp2anyreg(fs, exp);
+      luaK_codeABx(fs, OP_SETGLOBAL, e, var->info);
+      break;
+    }
+    case VINDEXED: {
+      int e = luaK_exp2RK(fs, exp);
+      luaK_codeABC(fs, OP_SETTABLE, var->info, var->aux, e);
       break;
     }
     default: {
-      luaK_tostack(ls, v2, 1);  /* `v2' must be a value */
-      luaK_code1(fs, codes[op].opcode, codes[op].arg);
+      lua_assert(0);  /* invalid var kind to store */
+      break;
     }
   }
+  freeexp(fs, exp);
 }
 
 
-static void codelineinfo (FuncState *fs) {
-  Proto *f = fs->f;
-  LexState *ls = fs->ls;
-  if (ls->lastline > fs->lastline) {
-    luaM_growvector(fs->L, f->lineinfo, f->nlineinfo, 2, int,
-                    "line info overflow", MAX_INT);
-    if (ls->lastline > fs->lastline+1)
-      f->lineinfo[f->nlineinfo++] = -(ls->lastline - (fs->lastline+1));
-    f->lineinfo[f->nlineinfo++] = fs->pc;
-    fs->lastline = ls->lastline;
-  }
+void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
+  int func;
+  luaK_exp2anyreg(fs, e);
+  freeexp(fs, e);
+  func = fs->freereg;
+  luaK_reserveregs(fs, 2);
+  luaK_codeABC(fs, OP_SELF, func, e->info, luaK_exp2RK(fs, key));
+  freeexp(fs, key);
+  e->info = func;
+  e->k = VNONRELOC;
 }
 
 
-int luaK_code0 (FuncState *fs, OpCode o) {
-  return luaK_code2(fs, o, 0, 0);
+static void invertjump (FuncState *fs, expdesc *e) {
+  Instruction *pc = getjumpcontrol(fs, e->info);
+  lua_assert(testOpMode(GET_OPCODE(*pc), OpModeT) &&
+             GET_OPCODE(*pc) != OP_TEST);
+  SETARG_A(*pc, !(GETARG_A(*pc)));
 }
 
 
-int luaK_code1 (FuncState *fs, OpCode o, int arg1) {
-  return luaK_code2(fs, o, arg1, 0);
+static int jumponcond (FuncState *fs, expdesc *e, int cond) {
+  if (e->k == VRELOCABLE) {
+    Instruction ie = getcode(fs, e);
+    if (GET_OPCODE(ie) == OP_NOT) {
+      fs->pc--;  /* remove previous OP_NOT */
+      return luaK_condjump(fs, OP_TEST, NO_REG, GETARG_B(ie), !cond);
+    }
+    /* else go through */
+  }
+  discharge2anyreg(fs, e);
+  freeexp(fs, e);
+  return luaK_condjump(fs, OP_TEST, NO_REG, e->info, cond);
 }
 
 
-int luaK_code2 (FuncState *fs, OpCode o, int arg1, int arg2) {
-  Instruction i = previous_instruction(fs);
-  int delta = luaK_opproperties[o].push - luaK_opproperties[o].pop;
-  int optm = 0;  /* 1 when there is an optimization */
-  switch (o) {
-    case OP_CLOSURE: {
-      delta = -arg2+1;
+void luaK_goiftrue (FuncState *fs, expdesc *e) {
+  int pc;  /* pc of last jump */
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VK: case VTRUE: {
+      pc = NO_JUMP;  /* always true; do nothing */
       break;
     }
-    case OP_SETTABLE: {
-      delta = -arg2;
+    case VFALSE: {
+      pc = luaK_jump(fs);  /* always jump */
       break;
     }
-    case OP_SETLIST: {
-      if (arg2 == 0) return NO_JUMP;  /* nothing to do */
-      delta = -arg2;
+    case VJMP: {
+      invertjump(fs, e);
+      pc = e->info;
       break;
     }
-    case OP_SETMAP: {
-      if (arg1 == 0) return NO_JUMP;  /* nothing to do */
-      delta = -2*arg1;
+    default: {
+      pc = jumponcond(fs, e, 0);
       break;
     }
-    case OP_RETURN: {
-      if (GET_OPCODE(i) == OP_CALL && GETARG_B(i) == MULT_RET) {
-        SET_OPCODE(i, OP_TAILCALL);
-        SETARG_B(i, arg1);
-        optm = 1;
-      }
+  }
+  luaK_concat(fs, &e->f, pc);  /* insert last jump in `f' list */
+}
+
+
+void luaK_goiffalse (FuncState *fs, expdesc *e) {
+  int pc;  /* pc of last jump */
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VNIL: case VFALSE: {
+      pc = NO_JUMP;  /* always false; do nothing */
       break;
     }
-    case OP_PUSHNIL: {
-      if (arg1 == 0) return NO_JUMP;  /* nothing to do */
-      delta = arg1;
-      switch(GET_OPCODE(i)) {
-        case OP_PUSHNIL: SETARG_U(i, GETARG_U(i)+arg1); optm = 1; break;
-        default: break;
-      }
+    case VTRUE: {
+      pc = luaK_jump(fs);  /* always jump */
       break;
     }
-    case OP_POP: {
-      if (arg1 == 0) return NO_JUMP;  /* nothing to do */
-      delta = -arg1;
-      switch(GET_OPCODE(i)) {
-        case OP_SETTABLE: SETARG_B(i, GETARG_B(i)+arg1); optm = 1; break;
-        default: break;
-      }
+    case VJMP: {
+      pc = e->info;
       break;
     }
-    case OP_GETTABLE: {
-      switch(GET_OPCODE(i)) {
-        case OP_PUSHSTRING:  /* `t.x' */
-          SET_OPCODE(i, OP_GETDOTTED);
-          optm = 1;
-          break;
-        case OP_GETLOCAL:  /* `t[i]' */
-          SET_OPCODE(i, OP_GETINDEXED);
-          optm = 1;
-          break;
-        default: break;
-      }
+    default: {
+      pc = jumponcond(fs, e, 1);
       break;
     }
-    case OP_ADD: {
-      switch(GET_OPCODE(i)) {
-        case OP_PUSHINT: SET_OPCODE(i, OP_ADDI); optm = 1; break;  /* `a+k' */
-        default: break;
-      }
+  }
+  luaK_concat(fs, &e->t, pc);  /* insert last jump in `t' list */
+}
+
+
+static void codenot (FuncState *fs, expdesc *e) {
+  luaK_dischargevars(fs, e);
+  switch (e->k) {
+    case VNIL: case VFALSE: {
+      e->k = VTRUE;
       break;
     }
-    case OP_SUB: {
-      switch(GET_OPCODE(i)) {
-        case OP_PUSHINT:  /* `a-k' */
-          i = CREATE_S(OP_ADDI, -GETARG_S(i));
-          optm = 1;
-          break;
-        default: break;
-      }
+    case VK: case VTRUE: {
+      e->k = VFALSE;
       break;
     }
-    case OP_CONCAT: {
-      delta = -arg1+1;
-      switch(GET_OPCODE(i)) {
-        case OP_CONCAT:  /* `a..b..c' */
-          SETARG_U(i, GETARG_U(i)+1);
-          optm = 1;
-          break;
-        default: break;
-      }
+    case VJMP: {
+      invertjump(fs, e);
       break;
     }
-    case OP_MINUS: {
-      switch(GET_OPCODE(i)) {
-        case OP_PUSHINT:  /* `-k' */
-          SETARG_S(i, -GETARG_S(i));
-          optm = 1;
-          break;
-        case OP_PUSHNUM:  /* `-k' */
-          SET_OPCODE(i, OP_PUSHNEGNUM);
-          optm = 1;
-          break;
-        default: break;
-      }
+    case VRELOCABLE:
+    case VNONRELOC: {
+      discharge2anyreg(fs, e);
+      freeexp(fs, e);
+      e->info = luaK_codeABC(fs, OP_NOT, 0, e->info, 0);
+      e->k = VRELOCABLE;
       break;
     }
-    case OP_JMPNE: {
-      if (i == CREATE_U(OP_PUSHNIL, 1)) {  /* `a~=nil' */
-        i = CREATE_S(OP_JMPT, NO_JUMP);
-        optm = 1;
-      }
+    default: {
+      lua_assert(0);  /* cannot happen */
       break;
     }
-    case OP_JMPEQ: {
-      if (i == CREATE_U(OP_PUSHNIL, 1)) {  /* `a==nil' */
-        i = CREATE_0(OP_NOT);
-        delta = -1;  /* just undo effect of previous PUSHNIL */
-        optm = 1;
-      }
-      break;
+  }
+  /* interchange true and false lists */
+  { int temp = e->f; e->f = e->t; e->t = temp; }
+}
+
+
+void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
+  t->aux = luaK_exp2RK(fs, k);
+  t->k = VINDEXED;
+}
+
+
+void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e) {
+  if (op == OPR_MINUS) {
+    luaK_exp2val(fs, e);
+    if (e->k == VK && ttisnumber(&fs->f->k[e->info]))
+      e->info = luaK_numberK(fs, -nvalue(&fs->f->k[e->info]));
+    else {
+      luaK_exp2anyreg(fs, e);
+      freeexp(fs, e);
+      e->info = luaK_codeABC(fs, OP_UNM, 0, e->info, 0);
+      e->k = VRELOCABLE;
     }
-    case OP_JMPT:
-    case OP_JMPONT: {
-      switch (GET_OPCODE(i)) {
-        case OP_NOT: {
-          i = CREATE_S(OP_JMPF, NO_JUMP);
-          optm = 1;
-          break;
-        }
-        case OP_PUSHINT: {
-          if (o == OP_JMPT) {  /* JMPONT must keep original integer value */
-            i = CREATE_S(OP_JMP, NO_JUMP);
-            optm = 1;
-          }
-          break;
-        }
-        case OP_PUSHNIL: {
-          if (GETARG_U(i) == 1) {
-            fs->pc--;  /* erase previous instruction */
-            luaK_deltastack(fs, -1);  /* correct stack */
-            return NO_JUMP; 
-          }
-          break;
-        }
-        default: break;
-      }
+  }
+  else  /* op == NOT */
+    codenot(fs, e);
+}
+
+
+void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
+  switch (op) {
+    case OPR_AND: {
+      luaK_goiftrue(fs, v);
+      luaK_patchtohere(fs, v->t);
+      v->t = NO_JUMP;
       break;
     }
-    case OP_JMPF:
-    case OP_JMPONF: {
-      switch (GET_OPCODE(i)) {
-        case OP_NOT: {
-          i = CREATE_S(OP_JMPT, NO_JUMP);
-          optm = 1;
-          break;
-        }
-        case OP_PUSHINT: {  /* `while 1 do ...' */
-          fs->pc--;  /* erase previous instruction */
-          luaK_deltastack(fs, -1);  /* correct stack */
-          return NO_JUMP; 
-        }
-        case OP_PUSHNIL: {  /* `repeat ... until nil' */
-          if (GETARG_U(i) == 1) {
-            i = CREATE_S(OP_JMP, NO_JUMP);
-            optm = 1;
-          }
-          break;
-        }
-        default: break;
-      }
+    case OPR_OR: {
+      luaK_goiffalse(fs, v);
+      luaK_patchtohere(fs, v->f);
+      v->f = NO_JUMP;
       break;
     }
-    case OP_GETDOTTED:
-    case OP_GETINDEXED:
-    case OP_TAILCALL:
-    case OP_ADDI: {
-      LUA_INTERNALERROR("instruction used only for optimizations");
+    case OPR_CONCAT: {
+      luaK_exp2nextreg(fs, v);  /* operand must be on the `stack' */
       break;
     }
     default: {
-      LUA_ASSERT(delta != VD, "invalid delta");
+      luaK_exp2RK(fs, v);
       break;
     }
   }
-  luaK_deltastack(fs, delta);
-  if (optm) {  /* optimize: put instruction in place of last one */
-      fs->f->code[fs->pc-1] = i;  /* change previous instruction */
-      return fs->pc-1;  /* do not generate new instruction */
+}
+
+
+static void codebinop (FuncState *fs, expdesc *res, BinOpr op,
+                       int o1, int o2) {
+  if (op <= OPR_POW) {  /* arithmetic operator? */
+    OpCode opc = cast(OpCode, (op - OPR_ADD) + OP_ADD);  /* ORDER OP */
+    res->info = luaK_codeABC(fs, opc, 0, o1, o2);
+    res->k = VRELOCABLE;
   }
-  /* else build new instruction */
-  switch ((enum Mode)luaK_opproperties[o].mode) {
-    case iO: i = CREATE_0(o); break;
-    case iU: i = CREATE_U(o, arg1); break;
-    case iS: i = CREATE_S(o, arg1); break;
-    case iAB: i = CREATE_AB(o, arg1, arg2); break;
+  else {  /* test operator */
+    static const OpCode ops[] = {OP_EQ, OP_EQ, OP_LT, OP_LE, OP_LT, OP_LE};
+    int cond = 1;
+    if (op >= OPR_GT) {  /* `>' or `>='? */
+      int temp;  /* exchange args and replace by `<' or `<=' */
+      temp = o1; o1 = o2; o2 = temp;  /* o1 <==> o2 */
+    }
+    else if (op == OPR_NE) cond = 0;
+    res->info = luaK_condjump(fs, ops[op - OPR_NE], cond, o1, o2);
+    res->k = VJMP;
   }
-  codelineinfo(fs);
+}
+
+
+void luaK_posfix (FuncState *fs, BinOpr op, expdesc *e1, expdesc *e2) {
+  switch (op) {
+    case OPR_AND: {
+      lua_assert(e1->t == NO_JUMP);  /* list must be closed */
+      luaK_dischargevars(fs, e2);
+      luaK_concat(fs, &e1->f, e2->f);
+      e1->k = e2->k; e1->info = e2->info; e1->aux = e2->aux; e1->t = e2->t;
+      break;
+    }
+    case OPR_OR: {
+      lua_assert(e1->f == NO_JUMP);  /* list must be closed */
+      luaK_dischargevars(fs, e2);
+      luaK_concat(fs, &e1->t, e2->t);
+      e1->k = e2->k; e1->info = e2->info; e1->aux = e2->aux; e1->f = e2->f;
+      break;
+    }
+    case OPR_CONCAT: {
+      luaK_exp2val(fs, e2);
+      if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
+        lua_assert(e1->info == GETARG_B(getcode(fs, e2))-1);
+        freeexp(fs, e1);
+        SETARG_B(getcode(fs, e2), e1->info);
+        e1->k = e2->k; e1->info = e2->info;
+      }
+      else {
+        luaK_exp2nextreg(fs, e2);
+        freeexp(fs, e2);
+        freeexp(fs, e1);
+        e1->info = luaK_codeABC(fs, OP_CONCAT, 0, e1->info, e2->info);
+        e1->k = VRELOCABLE;
+      }
+      break;
+    }
+    default: {
+      int o1 = luaK_exp2RK(fs, e1);
+      int o2 = luaK_exp2RK(fs, e2);
+      freeexp(fs, e2);
+      freeexp(fs, e1);
+      codebinop(fs, e1, op, o1, o2);
+    }
+  }
+}
+
+
+void luaK_fixline (FuncState *fs, int line) {
+  fs->f->lineinfo[fs->pc - 1] = line;
+}
+
+
+int luaK_code (FuncState *fs, Instruction i, int line) {
+  Proto *f = fs->f;
+  luaK_dischargejpc(fs);  /* `pc' will change */
   /* put new instruction in code array */
-  luaM_growvector(fs->L, fs->f->code, fs->pc, 1, Instruction,
-                  "code size overflow", MAX_INT);
-  fs->f->code[fs->pc] = i;
+  luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
+                  MAX_INT, "code size overflow");
+  f->code[fs->pc] = i;
+  /* save corresponding line information */
+  luaM_growvector(fs->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
+                  MAX_INT, "code size overflow");
+  f->lineinfo[fs->pc] = line;
   return fs->pc++;
 }
 
 
-const struct OpProperties luaK_opproperties[NUM_OPCODES] = {
-  {iO, 0, 0},	/* OP_END */
-  {iU, 0, 0},	/* OP_RETURN */
-  {iAB, 0, 0},	/* OP_CALL */
-  {iAB, 0, 0},	/* OP_TAILCALL */
-  {iU, VD, 0},	/* OP_PUSHNIL */
-  {iU, VD, 0},	/* OP_POP */
-  {iS, 1, 0},	/* OP_PUSHINT */
-  {iU, 1, 0},	/* OP_PUSHSTRING */
-  {iU, 1, 0},	/* OP_PUSHNUM */
-  {iU, 1, 0},	/* OP_PUSHNEGNUM */
-  {iU, 1, 0},	/* OP_PUSHUPVALUE */
-  {iU, 1, 0},	/* OP_GETLOCAL */
-  {iU, 1, 0},	/* OP_GETGLOBAL */
-  {iO, 1, 2},	/* OP_GETTABLE */
-  {iU, 1, 1},	/* OP_GETDOTTED */
-  {iU, 1, 1},	/* OP_GETINDEXED */
-  {iU, 2, 1},	/* OP_PUSHSELF */
-  {iU, 1, 0},	/* OP_CREATETABLE */
-  {iU, 0, 1},	/* OP_SETLOCAL */
-  {iU, 0, 1},	/* OP_SETGLOBAL */
-  {iAB, VD, 0},	/* OP_SETTABLE */
-  {iAB, VD, 0},	/* OP_SETLIST */
-  {iU, VD, 0},	/* OP_SETMAP */
-  {iO, 1, 2},	/* OP_ADD */
-  {iS, 1, 1},	/* OP_ADDI */
-  {iO, 1, 2},	/* OP_SUB */
-  {iO, 1, 2},	/* OP_MULT */
-  {iO, 1, 2},	/* OP_DIV */
-  {iO, 1, 2},	/* OP_POW */
-  {iU, VD, 0},	/* OP_CONCAT */
-  {iO, 1, 1},	/* OP_MINUS */
-  {iO, 1, 1},	/* OP_NOT */
-  {iS, 0, 2},	/* OP_JMPNE */
-  {iS, 0, 2},	/* OP_JMPEQ */
-  {iS, 0, 2},	/* OP_JMPLT */
-  {iS, 0, 2},	/* OP_JMPLE */
-  {iS, 0, 2},	/* OP_JMPGT */
-  {iS, 0, 2},	/* OP_JMPGE */
-  {iS, 0, 1},	/* OP_JMPT */
-  {iS, 0, 1},	/* OP_JMPF */
-  {iS, 0, 1},	/* OP_JMPONT */
-  {iS, 0, 1},	/* OP_JMPONF */
-  {iS, 0, 0},	/* OP_JMP */
-  {iO, 0, 0},	/* OP_PUSHNILJMP */
-  {iS, 0, 0},	/* OP_FORPREP */
-  {iS, 0, 3},	/* OP_FORLOOP */
-  {iS, 2, 0},	/* OP_LFORPREP */
-  {iS, 0, 3},	/* OP_LFORLOOP */
-  {iAB, VD, 0}	/* OP_CLOSURE */
-};
+int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
+  lua_assert(getOpMode(o) == iABC);
+  return luaK_code(fs, CREATE_ABC(o, a, b, c), fs->ls->lastline);
+}
+
+
+int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
+  lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
+  return luaK_code(fs, CREATE_ABx(o, a, bc), fs->ls->lastline);
+}
 
diff --git a/src/lcode.h b/src/lcode.h
index 3f0a209a..74908c65 100644
--- a/src/lcode.h
+++ b/src/lcode.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.h,v 1.16 2000/08/09 14:49:13 roberto Exp $
+** $Id: lcode.h,v 1.38 2002/12/11 12:34:22 roberto Exp $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -26,45 +26,49 @@
 typedef enum BinOpr {
   OPR_ADD, OPR_SUB, OPR_MULT, OPR_DIV, OPR_POW,
   OPR_CONCAT,
-  OPR_NE, OPR_EQ, OPR_LT, OPR_LE, OPR_GT, OPR_GE,
+  OPR_NE, OPR_EQ,
+  OPR_LT, OPR_LE, OPR_GT, OPR_GE,
   OPR_AND, OPR_OR,
   OPR_NOBINOPR
 } BinOpr;
 
-typedef enum UnOpr { OPR_MINUS, OPR_NOT, OPR_NOUNOPR } UnOpr;
-
+#define binopistest(op)	((op) >= OPR_NE)
 
-enum Mode {iO, iU, iS, iAB};  /* instruction format */
+typedef enum UnOpr { OPR_MINUS, OPR_NOT, OPR_NOUNOPR } UnOpr;
 
-#define VD	100	/* flag for variable delta */
 
-extern const struct OpProperties {
-  char mode;
-  unsigned char push;
-  unsigned char pop;
-} luaK_opproperties[];
+#define getcode(fs,e)	((fs)->f->code[(e)->info])
 
+#define luaK_codeAsBx(fs,o,A,sBx)	luaK_codeABx(fs,o,A,(sBx)+MAXARG_sBx)
 
-void luaK_error (LexState *ls, const char *msg);
-int luaK_code0 (FuncState *fs, OpCode o);
-int luaK_code1 (FuncState *fs, OpCode o, int arg1);
-int luaK_code2 (FuncState *fs, OpCode o, int arg1, int arg2);
+int luaK_code (FuncState *fs, Instruction i, int line);
+int luaK_codeABx (FuncState *fs, OpCode o, int A, unsigned int Bx);
+int luaK_codeABC (FuncState *fs, OpCode o, int A, int B, int C);
+void luaK_fixline (FuncState *fs, int line);
+void luaK_nil (FuncState *fs, int from, int n);
+void luaK_reserveregs (FuncState *fs, int n);
+void luaK_checkstack (FuncState *fs, int n);
+int luaK_stringK (FuncState *fs, TString *s);
+int luaK_numberK (FuncState *fs, lua_Number r);
+void luaK_dischargevars (FuncState *fs, expdesc *e);
+int luaK_exp2anyreg (FuncState *fs, expdesc *e);
+void luaK_exp2nextreg (FuncState *fs, expdesc *e);
+void luaK_exp2val (FuncState *fs, expdesc *e);
+int luaK_exp2RK (FuncState *fs, expdesc *e);
+void luaK_self (FuncState *fs, expdesc *e, expdesc *key);
+void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k);
+void luaK_goiftrue (FuncState *fs, expdesc *e);
+void luaK_goiffalse (FuncState *fs, expdesc *e);
+void luaK_storevar (FuncState *fs, expdesc *var, expdesc *e);
+void luaK_setcallreturns (FuncState *fs, expdesc *var, int nresults);
 int luaK_jump (FuncState *fs);
 void luaK_patchlist (FuncState *fs, int list, int target);
+void luaK_patchtohere (FuncState *fs, int list);
 void luaK_concat (FuncState *fs, int *l1, int l2);
-void luaK_goiftrue (FuncState *fs, expdesc *v, int keepvalue);
 int luaK_getlabel (FuncState *fs);
-void luaK_deltastack (FuncState *fs, int delta);
-void luaK_kstr (LexState *ls, int c);
-void luaK_number (FuncState *fs, Number f);
-void luaK_adjuststack (FuncState *fs, int n);
-int luaK_lastisopen (FuncState *fs);
-void luaK_setcallreturns (FuncState *fs, int nresults);
-void luaK_tostack (LexState *ls, expdesc *v, int onlyone);
-void luaK_storevar (LexState *ls, const expdesc *var);
-void luaK_prefix (LexState *ls, UnOpr op, expdesc *v);
-void luaK_infix (LexState *ls, BinOpr op, expdesc *v);
-void luaK_posfix (LexState *ls, BinOpr op, expdesc *v1, expdesc *v2);
+void luaK_prefix (FuncState *fs, UnOpr op, expdesc *v);
+void luaK_infix (FuncState *fs, BinOpr op, expdesc *v);
+void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1, expdesc *v2);
 
 
 #endif
diff --git a/src/ldebug.c b/src/ldebug.c
index a5a2ab1d..8e511e3b 100644
--- a/src/ldebug.c
+++ b/src/ldebug.c
@@ -1,11 +1,14 @@
 /*
-** $Id: ldebug.c,v 1.50 2000/10/30 12:38:50 roberto Exp $
+** $Id: ldebug.c,v 1.150 2003/03/19 21:24:04 roberto Exp $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
 
 
 #include <stdlib.h>
+#include <string.h>
+
+#define ldebug_c
 
 #include "lua.h"
 
@@ -20,447 +23,563 @@
 #include "lstring.h"
 #include "ltable.h"
 #include "ltm.h"
-#include "luadebug.h"
+#include "lvm.h"
 
 
 
-static const char *getfuncname (lua_State *L, StkId f, const char **name);
+static const char *getfuncname (CallInfo *ci, const char **name);
 
 
-static void setnormalized (TObject *d, const TObject *s) {
-  if (ttype(s) == LUA_TMARK) {
-    clvalue(d) = infovalue(s)->func;
-    ttype(d) = LUA_TFUNCTION;
-  }
-  else *d = *s;
-}
+#define isLua(ci)	(!((ci)->state & CI_C))
 
 
-static int isLmark (StkId o) {
-  return (o && ttype(o) == LUA_TMARK && !infovalue(o)->func->isC);
+static int currentpc (CallInfo *ci) {
+  if (!isLua(ci)) return -1;  /* function is not a Lua function? */
+  if (ci->state & CI_HASFRAME)  /* function has a frame? */
+    ci->u.l.savedpc = *ci->u.l.pc;  /* use `pc' from there */
+  /* function's pc is saved */
+  return pcRel(ci->u.l.savedpc, ci_func(ci)->l.p);
 }
 
 
-LUA_API lua_Hook lua_setcallhook (lua_State *L, lua_Hook func) {
-  lua_Hook oldhook = L->callhook;
-  L->callhook = func;
-  return oldhook;
+static int currentline (CallInfo *ci) {
+  int pc = currentpc(ci);
+  if (pc < 0)
+    return -1;  /* only active lua functions have current-line information */
+  else
+    return getline(ci_func(ci)->l.p, pc);
 }
 
 
-LUA_API lua_Hook lua_setlinehook (lua_State *L, lua_Hook func) {
-  lua_Hook oldhook = L->linehook;
-  L->linehook = func;
-  return oldhook;
+void luaG_inithooks (lua_State *L) {
+  CallInfo *ci;
+  for (ci = L->ci; ci != L->base_ci; ci--)  /* update all `savedpc's */
+    currentpc(ci);
+  L->hookinit = 1;
 }
 
 
-static StkId aux_stackedfunction (lua_State *L, int level, StkId top) {
-  int i;
-  for (i = (top-1) - L->stack; i>=0; i--) {
-    if (is_T_MARK(L->stack[i].ttype)) {
-      if (level == 0)
-        return L->stack+i;
-      level--;
-    }
+/*
+** this function can be called asynchronous (e.g. during a signal)
+*/
+LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
+  if (func == NULL || mask == 0) {  /* turn off hooks? */
+    mask = 0;
+    func = NULL;
   }
-  return NULL;
+  L->hook = func;
+  L->basehookcount = count;
+  resethookcount(L);
+  L->hookmask = cast(lu_byte, mask);
+  L->hookinit = 0;
+  return 1;
 }
 
 
-LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
-  StkId f = aux_stackedfunction(L, level, L->top);
-  if (f == NULL) return 0;  /* there is no such level */
-  else {
-    ar->_func = f;
-    return 1;
-  }
+LUA_API lua_Hook lua_gethook (lua_State *L) {
+  return L->hook;
 }
 
 
-static int nups (StkId f) {
-  switch (ttype(f)) {
-    case LUA_TFUNCTION:
-      return clvalue(f)->nupvalues;
-    case LUA_TMARK:
-      return infovalue(f)->func->nupvalues;
-    default:
-      return 0;
-  }
+LUA_API int lua_gethookmask (lua_State *L) {
+  return L->hookmask;
 }
 
 
-int luaG_getline (int *lineinfo, int pc, int refline, int *prefi) {
-  int refi;
-  if (lineinfo == NULL || pc == -1)
-    return -1;  /* no line info or function is not active */
-  refi = prefi ? *prefi : 0;
-  if (lineinfo[refi] < 0)
-    refline += -lineinfo[refi++]; 
-  LUA_ASSERT(lineinfo[refi] >= 0, "invalid line info");
-  while (lineinfo[refi] > pc) {
-    refline--;
-    refi--;
-    if (lineinfo[refi] < 0)
-      refline -= -lineinfo[refi--]; 
-    LUA_ASSERT(lineinfo[refi] >= 0, "invalid line info");
-  }
-  for (;;) {
-    int nextline = refline + 1;
-    int nextref = refi + 1;
-    if (lineinfo[nextref] < 0)
-      nextline += -lineinfo[nextref++]; 
-    LUA_ASSERT(lineinfo[nextref] >= 0, "invalid line info");
-    if (lineinfo[nextref] > pc)
-      break;
-    refline = nextline;
-    refi = nextref;
-  }
-  if (prefi) *prefi = refi;
-  return refline;
+LUA_API int lua_gethookcount (lua_State *L) {
+  return L->basehookcount;
 }
 
 
-static int currentpc (StkId f) {
-  CallInfo *ci = infovalue(f);
-  LUA_ASSERT(isLmark(f), "function has no pc");
-  if (ci->pc)
-    return (*ci->pc - ci->func->f.l->code) - 1;
-  else
-    return -1;  /* function is not active */
-}
-
-
-static int currentline (StkId f) {
-  if (!isLmark(f))
-    return -1;  /* only active lua functions have current-line information */
+LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
+  int status;
+  CallInfo *ci;
+  lua_lock(L);
+  for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) {
+    level--;
+    if (!(ci->state & CI_C))  /* Lua function? */
+      level -= ci->u.l.tailcalls;  /* skip lost tail calls */
+  }
+  if (level > 0 || ci == L->base_ci) status = 0;  /* there is no such level */
+  else if (level < 0) {  /* level is of a lost tail call */
+    status = 1;
+    ar->i_ci = 0;
+  }
   else {
-    CallInfo *ci = infovalue(f);
-    int *lineinfo = ci->func->f.l->lineinfo;
-    return luaG_getline(lineinfo, currentpc(f), 1, NULL);
+    status = 1;
+    ar->i_ci = ci - L->base_ci;
   }
+  lua_unlock(L);
+  return status;
 }
 
 
-
-static Proto *getluaproto (StkId f) {
-  return (isLmark(f) ?  infovalue(f)->func->f.l : NULL);
+static Proto *getluaproto (CallInfo *ci) {
+  return (isLua(ci) ? ci_func(ci)->l.p : NULL);
 }
 
 
 LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
   const char *name;
-  StkId f = ar->_func;
-  Proto *fp = getluaproto(f);
-  if (!fp) return NULL;  /* `f' is not a Lua function? */
-  name = luaF_getlocalname(fp, n, currentpc(f));
-  if (!name) return NULL;
-  luaA_pushobject(L, (f+1)+(n-1));  /* push value */
+  CallInfo *ci;
+  Proto *fp;
+  lua_lock(L);
+  name = NULL;
+  ci = L->base_ci + ar->i_ci;
+  fp = getluaproto(ci);
+  if (fp) {  /* is a Lua function? */
+    name = luaF_getlocalname(fp, n, currentpc(ci));
+    if (name)
+      luaA_pushobject(L, ci->base+(n-1));  /* push value */
+  }
+  lua_unlock(L);
   return name;
 }
 
 
 LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
   const char *name;
-  StkId f = ar->_func;
-  Proto *fp = getluaproto(f);
+  CallInfo *ci;
+  Proto *fp;
+  lua_lock(L);
+  name = NULL;
+  ci = L->base_ci + ar->i_ci;
+  fp = getluaproto(ci);
   L->top--;  /* pop new value */
-  if (!fp) return NULL;  /* `f' is not a Lua function? */
-  name = luaF_getlocalname(fp, n, currentpc(f));
-  if (!name || name[0] == '(') return NULL;  /* `(' starts private locals */
-  *((f+1)+(n-1)) = *L->top;
+  if (fp) {  /* is a Lua function? */
+    name = luaF_getlocalname(fp, n, currentpc(ci));
+    if (!name || name[0] == '(')  /* `(' starts private locals */
+      name = NULL;
+    else
+      setobjs2s(ci->base+(n-1), L->top);
+  }
+  lua_unlock(L);
   return name;
 }
 
 
-static void infoLproto (lua_Debug *ar, Proto *f) {
-  ar->source = f->source->str;
-  ar->linedefined = f->lineDefined;
-  ar->what = "Lua";
-}
-
-
-static void funcinfo (lua_State *L, lua_Debug *ar, StkId func) {
-  Closure *cl = NULL;
-  switch (ttype(func)) {
-    case LUA_TFUNCTION:
-      cl = clvalue(func);
-      break;
-    case LUA_TMARK:
-      cl = infovalue(func)->func;
-      break;
-    default:
-      lua_error(L, "value for `lua_getinfo' is not a function");
-  }
-  if (cl->isC) {
-    ar->source = "=C";
+static void funcinfo (lua_Debug *ar, StkId func) {
+  Closure *cl = clvalue(func);
+  if (cl->c.isC) {
+    ar->source = "=[C]";
     ar->linedefined = -1;
     ar->what = "C";
   }
-  else
-    infoLproto(ar, cl->f.l);
-  luaO_chunkid(ar->short_src, ar->source, sizeof(ar->short_src));
-  if (ar->linedefined == 0)
-    ar->what = "main";
-}
-
-
-static const char *travtagmethods (lua_State *L, const TObject *o) {
-  if (ttype(o) == LUA_TFUNCTION) {
-    int e;
-    for (e=0; e<TM_N; e++) {
-      int t;
-      for (t=0; t<=L->last_tag; t++)
-        if (clvalue(o) == luaT_gettm(L, t, e))
-          return luaT_eventname[e];
-    }
+  else {
+    ar->source = getstr(cl->l.p->source);
+    ar->linedefined = cl->l.p->lineDefined;
+    ar->what = (ar->linedefined == 0) ? "main" : "Lua";
   }
-  return NULL;
+  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
 }
 
 
 static const char *travglobals (lua_State *L, const TObject *o) {
-  Hash *g = L->gt;
-  int i;
-  for (i=0; i<g->size; i++) {
-    if (luaO_equalObj(o, val(node(g, i))) &&
-        ttype(key(node(g, i))) == LUA_TSTRING) 
-      return tsvalue(key(node(g, i)))->str;
+  Table *g = hvalue(gt(L));
+  int i = sizenode(g);
+  while (i--) {
+    Node *n = gnode(g, i);
+    if (luaO_rawequalObj(o, gval(n)) && ttisstring(gkey(n)))
+      return getstr(tsvalue(gkey(n)));
   }
   return NULL;
 }
 
 
-static void getname (lua_State *L, StkId f, lua_Debug *ar) {
-  TObject o;
-  setnormalized(&o, f);
-  /* try to find a name for given function */
-  if ((ar->name = travglobals(L, &o)) != NULL)
-    ar->namewhat = "global";
-  /* not found: try tag methods */
-  else if ((ar->name = travtagmethods(L, &o)) != NULL)
-    ar->namewhat = "tag-method";
-  else ar->namewhat = "";  /* not found at all */
+static void info_tailcall (lua_State *L, lua_Debug *ar) {
+  ar->name = ar->namewhat = "";
+  ar->what = "tail";
+  ar->linedefined = ar->currentline = -1;
+  ar->source = "=(tail call)";
+  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
+  ar->nups = 0;
+  setnilvalue(L->top);
 }
 
 
-LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
-  StkId func;
-  int isactive = (*what != '>');
-  if (isactive)
-    func = ar->_func;
-  else {
-    what++;  /* skip the '>' */
-    func = L->top - 1;
-  }
+static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
+                    StkId f, CallInfo *ci) {
+  int status = 1;
   for (; *what; what++) {
     switch (*what) {
       case 'S': {
-        funcinfo(L, ar, func);
+        funcinfo(ar, f);
         break;
       }
       case 'l': {
-        ar->currentline = currentline(func);
+        ar->currentline = (ci) ? currentline(ci) : -1;
         break;
       }
       case 'u': {
-        ar->nups = nups(func);
+        ar->nups = clvalue(f)->c.nupvalues;
         break;
       }
       case 'n': {
-        ar->namewhat = (isactive) ? getfuncname(L, func, &ar->name) : NULL;
-        if (ar->namewhat == NULL)
-          getname(L, func, ar);
+        ar->namewhat = (ci) ? getfuncname(ci, &ar->name) : NULL;
+        if (ar->namewhat == NULL) {
+          /* try to find a global name */
+          if ((ar->name = travglobals(L, f)) != NULL)
+            ar->namewhat = "global";
+          else ar->namewhat = "";  /* not found */
+        }
         break;
       }
       case 'f': {
-        setnormalized(L->top, func);
-        incr_top;  /* push function */
+        setobj2s(L->top, f);
         break;
       }
-      default: return 0;  /* invalid option */
+      default: status = 0;  /* invalid option */
     }
   }
-  if (!isactive) L->top--;  /* pop function */
-  return 1;
+  return status;
+}
+
+
+LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
+  int status = 1;
+  lua_lock(L);
+  if (*what == '>') {
+    StkId f = L->top - 1;
+    if (!ttisfunction(f))
+      luaG_runerror(L, "value for `lua_getinfo' is not a function");
+    status = auxgetinfo(L, what + 1, ar, f, NULL);
+    L->top--;  /* pop function */
+  }
+  else if (ar->i_ci != 0) {  /* no tail call? */
+    CallInfo *ci = L->base_ci + ar->i_ci;
+    lua_assert(ttisfunction(ci->base - 1));
+    status = auxgetinfo(L, what, ar, ci->base - 1, ci);
+  }
+  else
+    info_tailcall(L, ar);
+  if (strchr(what, 'f')) incr_top(L);
+  lua_unlock(L);
+  return status;
 }
 
 
 /*
 ** {======================================================
-** Symbolic Execution
+** Symbolic Execution and code checker
 ** =======================================================
 */
 
+#define check(x)		if (!(x)) return 0;
+
+#define checkjump(pt,pc)	check(0 <= pc && pc < pt->sizecode)
+
+#define checkreg(pt,reg)	check((reg) < (pt)->maxstacksize)
+
+
 
-static int pushpc (int *stack, int pc, int top, int n) {
-  while (n--)
-    stack[top++] = pc-1;
-  return top;
+static int precheck (const Proto *pt) {
+  check(pt->maxstacksize <= MAXSTACK);
+  check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
+  lua_assert(pt->numparams+pt->is_vararg <= pt->maxstacksize);
+  check(GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
+  return 1;
 }
 
 
-static Instruction luaG_symbexec (const Proto *pt, int lastpc, int stackpos) {
-  int stack[MAXSTACK];  /* stores last instruction that changed a stack entry */
-  const Instruction *code = pt->code;
-  int top = pt->numparams;
-  int pc = 0;
-  if (pt->is_vararg)  /* varargs? */
-    top++;  /* `arg' */
-  while (pc < lastpc) {
-    const Instruction i = code[pc++];
-    LUA_ASSERT(0 <= top && top <= pt->maxstacksize, "wrong stack");
-    switch (GET_OPCODE(i)) {
-      case OP_RETURN: {
-        LUA_ASSERT(top >= GETARG_U(i), "wrong stack");
-        top = GETARG_U(i);
+static int checkopenop (const Proto *pt, int pc) {
+  Instruction i = pt->code[pc+1];
+  switch (GET_OPCODE(i)) {
+    case OP_CALL:
+    case OP_TAILCALL:
+    case OP_RETURN: {
+      check(GETARG_B(i) == 0);
+      return 1;
+    }
+    case OP_SETLISTO: return 1;
+    default: return 0;  /* invalid instruction after an open call */
+  }
+}
+
+
+static int checkRK (const Proto *pt, int r) {
+  return (r < pt->maxstacksize || (r >= MAXSTACK && r-MAXSTACK < pt->sizek));
+}
+
+
+static Instruction luaG_symbexec (const Proto *pt, int lastpc, int reg) {
+  int pc;
+  int last;  /* stores position of last instruction that changed `reg' */
+  last = pt->sizecode-1;  /* points to final return (a `neutral' instruction) */
+  check(precheck(pt));
+  for (pc = 0; pc < lastpc; pc++) {
+    const Instruction i = pt->code[pc];
+    OpCode op = GET_OPCODE(i);
+    int a = GETARG_A(i);
+    int b = 0;
+    int c = 0;
+    checkreg(pt, a);
+    switch (getOpMode(op)) {
+      case iABC: {
+        b = GETARG_B(i);
+        c = GETARG_C(i);
+        if (testOpMode(op, OpModeBreg)) {
+          checkreg(pt, b);
+        }
+        else if (testOpMode(op, OpModeBrk))
+          check(checkRK(pt, b));
+        if (testOpMode(op, OpModeCrk))
+          check(checkRK(pt, c));
         break;
       }
-      case OP_TAILCALL: {
-        LUA_ASSERT(top >= GETARG_A(i), "wrong stack");
-        top = GETARG_B(i);
+      case iABx: {
+        b = GETARG_Bx(i);
+        if (testOpMode(op, OpModeK)) check(b < pt->sizek);
+        break;
+      }
+      case iAsBx: {
+        b = GETARG_sBx(i);
         break;
       }
-      case OP_CALL: {
-        int nresults = GETARG_B(i);
-        if (nresults == MULT_RET) nresults = 1;
-        LUA_ASSERT(top >= GETARG_A(i), "wrong stack");
-        top = pushpc(stack, pc, GETARG_A(i), nresults);
+    }
+    if (testOpMode(op, OpModesetA)) {
+      if (a == reg) last = pc;  /* change register `a' */
+    }
+    if (testOpMode(op, OpModeT)) {
+      check(pc+2 < pt->sizecode);  /* check skip */
+      check(GET_OPCODE(pt->code[pc+1]) == OP_JMP);
+    }
+    switch (op) {
+      case OP_LOADBOOL: {
+        check(c == 0 || pc+2 < pt->sizecode);  /* check its jump */
         break;
       }
-      case OP_PUSHNIL: {
-        top = pushpc(stack, pc, top, GETARG_U(i));
+      case OP_LOADNIL: {
+        if (a <= reg && reg <= b)
+          last = pc;  /* set registers from `a' to `b' */
         break;
       }
-      case OP_POP: {
-        top -= GETARG_U(i);
+      case OP_GETUPVAL:
+      case OP_SETUPVAL: {
+        check(b < pt->nups);
         break;
       }
-      case OP_SETTABLE:
-      case OP_SETLIST: {
-        top -= GETARG_B(i);
+      case OP_GETGLOBAL:
+      case OP_SETGLOBAL: {
+        check(ttisstring(&pt->k[b]));
         break;
       }
-      case OP_SETMAP: {
-        top -= 2*GETARG_U(i);
+      case OP_SELF: {
+        checkreg(pt, a+1);
+        if (reg == a+1) last = pc;
         break;
       }
       case OP_CONCAT: {
-        top -= GETARG_U(i);
-        stack[top++] = pc-1;
+        /* `c' is a register, and at least two operands */
+        check(c < MAXSTACK && b < c);
         break;
       }
-      case OP_CLOSURE: {
-        top -= GETARG_B(i);
-        stack[top++] = pc-1;
+      case OP_TFORLOOP:
+        checkreg(pt, a+c+5);
+        if (reg >= a) last = pc;  /* affect all registers above base */
+        /* go through */
+      case OP_FORLOOP:
+        checkreg(pt, a+2);
+        /* go through */
+      case OP_JMP: {
+        int dest = pc+1+b;
+	check(0 <= dest && dest < pt->sizecode);
+        /* not full check and jump is forward and do not skip `lastpc'? */
+        if (reg != NO_REG && pc < dest && dest <= lastpc)
+          pc += b;  /* do the jump */
         break;
       }
-      case OP_JMPONT:
-      case OP_JMPONF: {
-        int newpc = pc + GETARG_S(i);
-        /* jump is forward and do not skip `lastpc'? */
-        if (pc < newpc && newpc <= lastpc) {
-          stack[top-1] = pc-1;  /* value comes from `and'/`or' */
-          pc = newpc;  /* do the jump */
+      case OP_CALL:
+      case OP_TAILCALL: {
+        if (b != 0) {
+          checkreg(pt, a+b-1);
         }
-        else
-          top--;  /* do not jump; pop value */
+        c--;  /* c = num. returns */
+        if (c == LUA_MULTRET) {
+          check(checkopenop(pt, pc));
+        }
+        else if (c != 0)
+          checkreg(pt, a+c-1);
+        if (reg >= a) last = pc;  /* affect all registers above base */
         break;
       }
-      default: {
-        OpCode op = GET_OPCODE(i);
-        LUA_ASSERT(luaK_opproperties[op].push != VD,
-                   "invalid opcode for default");
-        top -= luaK_opproperties[op].pop;
-        LUA_ASSERT(top >= 0, "wrong stack");
-        top = pushpc(stack, pc, top, luaK_opproperties[op].push);
+      case OP_RETURN: {
+        b--;  /* b = num. returns */
+        if (b > 0) checkreg(pt, a+b-1);
+        break;
+      }
+      case OP_SETLIST: {
+        checkreg(pt, a + (b&(LFIELDS_PER_FLUSH-1)) + 1);
+        break;
+      }
+      case OP_CLOSURE: {
+        int nup;
+        check(b < pt->sizep);
+        nup = pt->p[b]->nups;
+        check(pc + nup < pt->sizecode);
+        for (; nup>0; nup--) {
+          OpCode op1 = GET_OPCODE(pt->code[pc+nup]);
+          check(op1 == OP_GETUPVAL || op1 == OP_MOVE);
+        }
+        break;
       }
+      default: break;
     }
   }
-  return code[stack[stackpos]];
+  return pt->code[last];
 }
 
+#undef check
+#undef checkjump
+#undef checkreg
 
-static const char *getobjname (lua_State *L, StkId obj, const char **name) {
-  StkId func = aux_stackedfunction(L, 0, obj);
-  if (!isLmark(func))
-    return NULL;  /* not an active Lua function */
-  else {
-    Proto *p = infovalue(func)->func->f.l;
-    int pc = currentpc(func);
-    int stackpos = obj - (func+1);  /* func+1 == function base */
-    Instruction i = luaG_symbexec(p, pc, stackpos);
-    LUA_ASSERT(pc != -1, "function must be active");
+/* }====================================================== */
+
+
+int luaG_checkcode (const Proto *pt) {
+  return luaG_symbexec(pt, pt->sizecode, NO_REG);
+}
+
+
+static const char *kname (Proto *p, int c) {
+  c = c - MAXSTACK;
+  if (c >= 0 && ttisstring(&p->k[c]))
+    return svalue(&p->k[c]);
+  else
+    return "?";
+}
+
+
+static const char *getobjname (CallInfo *ci, int stackpos, const char **name) {
+  if (isLua(ci)) {  /* a Lua function? */
+    Proto *p = ci_func(ci)->l.p;
+    int pc = currentpc(ci);
+    Instruction i;
+    *name = luaF_getlocalname(p, stackpos+1, pc);
+    if (*name)  /* is a local? */
+      return "local";
+    i = luaG_symbexec(p, pc, stackpos);  /* try symbolic execution */
+    lua_assert(pc != -1);
     switch (GET_OPCODE(i)) {
       case OP_GETGLOBAL: {
-        *name = p->kstr[GETARG_U(i)]->str;
+        int g = GETARG_Bx(i);  /* global index */
+        lua_assert(ttisstring(&p->k[g]));
+        *name = svalue(&p->k[g]);
         return "global";
       }
-      case OP_GETLOCAL: {
-        *name = luaF_getlocalname(p, GETARG_U(i)+1, pc);
-        LUA_ASSERT(*name, "local must exist");
-        return "local";
+      case OP_MOVE: {
+        int a = GETARG_A(i);
+        int b = GETARG_B(i);  /* move from `b' to `a' */
+        if (b < a)
+          return getobjname(ci, b, name);  /* get name for `b' */
+        break;
       }
-      case OP_PUSHSELF:
-      case OP_GETDOTTED: {
-        *name = p->kstr[GETARG_U(i)]->str;
+      case OP_GETTABLE: {
+        int k = GETARG_C(i);  /* key index */
+        *name = kname(p, k);
         return "field";
       }
-      default:
-        return NULL;  /* no useful name found */
+      case OP_SELF: {
+        int k = GETARG_C(i);  /* key index */
+        *name = kname(p, k);
+        return "method";
+      }
+      default: break;
     }
   }
+  return NULL;  /* no useful name found */
 }
 
 
-static const char *getfuncname (lua_State *L, StkId f, const char **name) {
-  StkId func = aux_stackedfunction(L, 0, f);  /* calling function */
-  if (!isLmark(func))
-    return NULL;  /* not an active Lua function */
-  else {
-    Proto *p = infovalue(func)->func->f.l;
-    int pc = currentpc(func);
-    Instruction i;
-    if (pc == -1) return NULL;  /* function is not activated */
-    i = p->code[pc];
-    switch (GET_OPCODE(i)) {
-      case OP_CALL: case OP_TAILCALL:
-        return getobjname(L, (func+1)+GETARG_A(i), name);
-      default:
-        return NULL;  /* no useful name found */
-    }
-  }
+static const char *getfuncname (CallInfo *ci, const char **name) {
+  Instruction i;
+  if ((isLua(ci) && ci->u.l.tailcalls > 0) || !isLua(ci - 1))
+    return NULL;  /* calling function is not Lua (or is unknown) */
+  ci--;  /* calling function */
+  i = ci_func(ci)->l.p->code[currentpc(ci)];
+  if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL)
+    return getobjname(ci, GETARG_A(i), name);
+  else
+    return NULL;  /* no useful name can be found */
 }
 
 
-/* }====================================================== */
+/* only ANSI way to check whether a pointer points to an array */
+static int isinstack (CallInfo *ci, const TObject *o) {
+  StkId p;
+  for (p = ci->base; p < ci->top; p++)
+    if (o == p) return 1;
+  return 0;
+}
 
 
-void luaG_typeerror (lua_State *L, StkId o, const char *op) {
-  const char *name;
-  const char *kind = getobjname(L, o, &name);
-  const char *t = luaO_typename(o);
+void luaG_typeerror (lua_State *L, const TObject *o, const char *op) {
+  const char *name = NULL;
+  const char *t = luaT_typenames[ttype(o)];
+  const char *kind = (isinstack(L->ci, o)) ?
+                         getobjname(L->ci, o - L->base, &name) : NULL;
   if (kind)
-    luaO_verror(L, "attempt to %.30s %.20s `%.40s' (a %.10s value)",
+    luaG_runerror(L, "attempt to %s %s `%s' (a %s value)",
                 op, kind, name, t);
   else
-    luaO_verror(L, "attempt to %.30s a %.10s value", op, t);
+    luaG_runerror(L, "attempt to %s a %s value", op, t);
+}
+
+
+void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
+  if (ttisstring(p1)) p1 = p2;
+  lua_assert(!ttisstring(p1));
+  luaG_typeerror(L, p1, "concatenate");
 }
 
 
-void luaG_binerror (lua_State *L, StkId p1, int t, const char *op) {
-  if (ttype(p1) == t) p1++;
-  LUA_ASSERT(ttype(p1) != t, "must be an error");
-  luaG_typeerror(L, p1, op);
+void luaG_aritherror (lua_State *L, const TObject *p1, const TObject *p2) {
+  TObject temp;
+  if (luaV_tonumber(p1, &temp) == NULL)
+    p2 = p1;  /* first operand is wrong */
+  luaG_typeerror(L, p2, "perform arithmetic on");
 }
 
 
-void luaG_ordererror (lua_State *L, StkId top) {
-  const char *t1 = luaO_typename(top-2);
-  const char *t2 = luaO_typename(top-1);
+int luaG_ordererror (lua_State *L, const TObject *p1, const TObject *p2) {
+  const char *t1 = luaT_typenames[ttype(p1)];
+  const char *t2 = luaT_typenames[ttype(p2)];
   if (t1[2] == t2[2])
-    luaO_verror(L, "attempt to compare two %.10s values", t1);
+    luaG_runerror(L, "attempt to compare two %s values", t1);
   else
-    luaO_verror(L, "attempt to compare %.10s with %.10s", t1, t2);
+    luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
+  return 0;
+}
+
+
+static void addinfo (lua_State *L, const char *msg) {
+  CallInfo *ci = L->ci;
+  if (isLua(ci)) {  /* is Lua code? */
+    char buff[LUA_IDSIZE];  /* add file:line information */
+    int line = currentline(ci);
+    luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE);
+    luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
+  }
+}
+
+
+void luaG_errormsg (lua_State *L) {
+  if (L->errfunc != 0) {  /* is there an error handling function? */
+    StkId errfunc = restorestack(L, L->errfunc);
+    if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
+    setobjs2s(L->top, L->top - 1);  /* move argument */
+    setobjs2s(L->top - 1, errfunc);  /* push function */
+    incr_top(L);
+    luaD_call(L, L->top - 2, 1);  /* call it */
+  }
+  luaD_throw(L, LUA_ERRRUN);
+}
+
+
+void luaG_runerror (lua_State *L, const char *fmt, ...) {
+  va_list argp;
+  va_start(argp, fmt);
+  addinfo(L, luaO_pushvfstring(L, fmt, argp));
+  va_end(argp);
+  luaG_errormsg(L);
 }
 
diff --git a/src/ldebug.h b/src/ldebug.h
index d4b2d3b0..7ff39583 100644
--- a/src/ldebug.h
+++ b/src/ldebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.h,v 1.7 2000/10/05 12:14:08 roberto Exp $
+** $Id: ldebug.h,v 1.32 2002/11/18 11:01:55 roberto Exp $
 ** Auxiliary functions from Debug Interface module
 ** See Copyright Notice in lua.h
 */
@@ -9,13 +9,23 @@
 
 
 #include "lstate.h"
-#include "luadebug.h"
 
 
-void luaG_typeerror (lua_State *L, StkId o, const char *op);
-void luaG_binerror (lua_State *L, StkId p1, int t, const char *op);
-int luaG_getline (int *lineinfo, int pc, int refline, int *refi);
-void luaG_ordererror (lua_State *L, StkId top);
+#define pcRel(pc, p)	(cast(int, (pc) - (p)->code) - 1)
+
+#define getline(f,pc)	(((f)->lineinfo) ? (f)->lineinfo[pc] : 0)
+
+#define resethookcount(L)	(L->hookcount = L->basehookcount)
+
+
+void luaG_inithooks (lua_State *L);
+void luaG_typeerror (lua_State *L, const TObject *o, const char *opname);
+void luaG_concaterror (lua_State *L, StkId p1, StkId p2);
+void luaG_aritherror (lua_State *L, const TObject *p1, const TObject *p2);
+int luaG_ordererror (lua_State *L, const TObject *p1, const TObject *p2);
+void luaG_runerror (lua_State *L, const char *fmt, ...);
+void luaG_errormsg (lua_State *L);
+int luaG_checkcode (const Proto *pt);
 
 
 #endif
diff --git a/src/ldo.c b/src/ldo.c
index 8a779bbe..ae4f22fd 100644
--- a/src/ldo.c
+++ b/src/ldo.c
@@ -1,22 +1,25 @@
 /*
-** $Id: ldo.c,v 1.109a 2000/10/30 12:38:50 roberto Exp $
+** $Id: ldo.c,v 1.217 2003/04/03 13:35:34 roberto Exp $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
 
 
 #include <setjmp.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#define ldo_c
+
 #include "lua.h"
 
 #include "ldebug.h"
 #include "ldo.h"
+#include "lfunc.h"
 #include "lgc.h"
 #include "lmem.h"
 #include "lobject.h"
+#include "lopcodes.h"
 #include "lparser.h"
 #include "lstate.h"
 #include "lstring.h"
@@ -27,362 +30,429 @@
 #include "lzio.h"
 
 
-/* space to handle stack overflow errors */
-#define EXTRA_STACK	(2*LUA_MINSTACK)
 
 
-void luaD_init (lua_State *L, int stacksize) {
-  L->stack = luaM_newvector(L, stacksize+EXTRA_STACK, TObject);
-  L->nblocks += stacksize*sizeof(TObject);
-  L->stack_last = L->stack+(stacksize-1);
-  L->stacksize = stacksize;
-  L->Cbase = L->top = L->stack;
-}
+/*
+** {======================================================
+** Error-recovery functions (based on long jumps)
+** =======================================================
+*/
 
 
-void luaD_checkstack (lua_State *L, int n) {
-  if (L->stack_last - L->top <= n) {  /* stack overflow? */
-    if (L->stack_last-L->stack > (L->stacksize-1)) {
-      /* overflow while handling overflow */
-      luaD_breakrun(L, LUA_ERRERR);  /* break run without error message */
+/* chain list of long jump buffers */
+struct lua_longjmp {
+  struct lua_longjmp *previous;
+  jmp_buf b;
+  volatile int status;  /* error code */
+};
+
+
+static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+  switch (errcode) {
+    case LUA_ERRMEM: {
+      setsvalue2s(oldtop, luaS_new(L, MEMERRMSG));
+      break;
+    }
+    case LUA_ERRERR: {
+      setsvalue2s(oldtop, luaS_new(L, "error in error handling"));
+      break;
     }
-    else {
-      L->stack_last += EXTRA_STACK;  /* to be used by error message */
-      lua_error(L, "stack overflow");
+    case LUA_ERRSYNTAX:
+    case LUA_ERRRUN: {
+      setobjs2s(oldtop, L->top - 1);  /* error message on current top */
+      break;
     }
   }
+  L->top = oldtop + 1;
+}
+
+
+void luaD_throw (lua_State *L, int errcode) {
+  if (L->errorJmp) {
+    L->errorJmp->status = errcode;
+    longjmp(L->errorJmp->b, 1);
+  }
+  else {
+    G(L)->panic(L);
+    exit(EXIT_FAILURE);
+  }
+}
+
+
+int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
+  struct lua_longjmp lj;
+  lj.status = 0;
+  lj.previous = L->errorJmp;  /* chain new error handler */
+  L->errorJmp = &lj;
+  if (setjmp(lj.b) == 0)
+    (*f)(L, ud);
+  L->errorJmp = lj.previous;  /* restore old error handler */
+  return lj.status;
 }
 
 
 static void restore_stack_limit (lua_State *L) {
-  if (L->top - L->stack < L->stacksize - 1)
-    L->stack_last = L->stack + (L->stacksize-1);
+  L->stack_last = L->stack+L->stacksize-1;
+  if (L->size_ci > LUA_MAXCALLS) {  /* there was an overflow? */
+    int inuse = (L->ci - L->base_ci);
+    if (inuse + 1 < LUA_MAXCALLS)  /* can `undo' overflow? */
+      luaD_reallocCI(L, LUA_MAXCALLS);
+  }
 }
 
+/* }====================================================== */
 
-/*
-** Adjust stack. Set top to base+extra, pushing NILs if needed.
-** (we cannot add base+extra unless we are sure it fits in the stack;
-**  otherwise the result of such operation on pointers is undefined)
-*/
-void luaD_adjusttop (lua_State *L, StkId base, int extra) {
-  int diff = extra-(L->top-base);
-  if (diff <= 0)
-    L->top = base+extra;
-  else {
-    luaD_checkstack(L, diff);
-    while (diff--)
-      ttype(L->top++) = LUA_TNIL;
+
+static void correctstack (lua_State *L, TObject *oldstack) {
+  CallInfo *ci;
+  GCObject *up;
+  L->top = (L->top - oldstack) + L->stack;
+  for (up = L->openupval; up != NULL; up = up->gch.next)
+    gcotouv(up)->v = (gcotouv(up)->v - oldstack) + L->stack;
+  for (ci = L->base_ci; ci <= L->ci; ci++) {
+    ci->top = (ci->top - oldstack) + L->stack;
+    ci->base = (ci->base - oldstack) + L->stack;
   }
+  L->base = L->ci->base;
 }
 
 
-/*
-** Open a hole inside the stack at `pos'
-*/
-static void luaD_openstack (lua_State *L, StkId pos) {
-  int i = L->top-pos; 
-  while (i--) pos[i+1] = pos[i];
-  incr_top;
+void luaD_reallocstack (lua_State *L, int newsize) {
+  TObject *oldstack = L->stack;
+  luaM_reallocvector(L, L->stack, L->stacksize, newsize, TObject);
+  L->stacksize = newsize;
+  L->stack_last = L->stack+newsize-1-EXTRA_STACK;
+  correctstack(L, oldstack);
 }
 
 
-static void dohook (lua_State *L, lua_Debug *ar, lua_Hook hook) {
-  StkId old_Cbase = L->Cbase;
-  StkId old_top = L->Cbase = L->top;
-  luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-  L->allowhooks = 0;  /* cannot call hooks inside a hook */
-  (*hook)(L, ar);
-  LUA_ASSERT(L->allowhooks == 0, "invalid allow");
-  L->allowhooks = 1;
-  L->top = old_top;
-  L->Cbase = old_Cbase;
+void luaD_reallocCI (lua_State *L, int newsize) {
+  CallInfo *oldci = L->base_ci;
+  luaM_reallocvector(L, L->base_ci, L->size_ci, newsize, CallInfo);
+  L->size_ci = cast(unsigned short, newsize);
+  L->ci = (L->ci - oldci) + L->base_ci;
+  L->end_ci = L->base_ci + L->size_ci;
 }
 
 
-void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook) {
-  if (L->allowhooks) {
-    lua_Debug ar;
-    ar._func = func;
-    ar.event = "line";
-    ar.currentline = line;
-    dohook(L, &ar, linehook);
+void luaD_growstack (lua_State *L, int n) {
+  if (n <= L->stacksize)  /* double size is enough? */
+    luaD_reallocstack(L, 2*L->stacksize);
+  else
+    luaD_reallocstack(L, L->stacksize + n + EXTRA_STACK);
+}
+
+
+static void luaD_growCI (lua_State *L) {
+  if (L->size_ci > LUA_MAXCALLS)  /* overflow while handling overflow? */
+    luaD_throw(L, LUA_ERRERR);
+  else {
+    luaD_reallocCI(L, 2*L->size_ci);
+    if (L->size_ci > LUA_MAXCALLS)
+      luaG_runerror(L, "stack overflow");
   }
 }
 
 
-static void luaD_callHook (lua_State *L, StkId func, lua_Hook callhook,
-                    const char *event) {
-  if (L->allowhooks) {
+void luaD_callhook (lua_State *L, int event, int line) {
+  lua_Hook hook = L->hook;
+  if (hook && L->allowhook) {
+    ptrdiff_t top = savestack(L, L->top);
+    ptrdiff_t ci_top = savestack(L, L->ci->top);
     lua_Debug ar;
-    ar._func = func;
     ar.event = event;
-    infovalue(func)->pc = NULL;  /* function is not active */
-    dohook(L, &ar, callhook);
+    ar.currentline = line;
+    if (event == LUA_HOOKTAILRET)
+      ar.i_ci = 0;  /* tail call; no debug information about it */
+    else
+      ar.i_ci = L->ci - L->base_ci;
+    luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
+    L->ci->top = L->top + LUA_MINSTACK;
+    L->allowhook = 0;  /* cannot call hooks inside a hook */
+    lua_unlock(L);
+    (*hook)(L, &ar);
+    lua_lock(L);
+    lua_assert(!L->allowhook);
+    L->allowhook = 1;
+    L->ci->top = restorestack(L, ci_top);
+    L->top = restorestack(L, top);
   }
 }
 
 
-static StkId callCclosure (lua_State *L, const struct Closure *cl, StkId base) {
-  int nup = cl->nupvalues;  /* number of upvalues */
-  StkId old_Cbase = L->Cbase;
-  int n;
-  L->Cbase = base;       /* new base for C function */
-  luaD_checkstack(L, nup+LUA_MINSTACK);  /* ensure minimum stack size */
-  for (n=0; n<nup; n++)  /* copy upvalues as extra arguments */
-    *(L->top++) = cl->upvalue[n];
-  n = (*cl->f.c)(L);  /* do the actual call */
-  L->Cbase = old_Cbase;  /* restore old C base */
-  return L->top - n;  /* return index of first result */
+static void adjust_varargs (lua_State *L, int nfixargs, StkId base) {
+  int i;
+  Table *htab;
+  TObject nname;
+  int actual = L->top - base;  /* actual number of arguments */
+  if (actual < nfixargs) {
+    luaD_checkstack(L, nfixargs - actual);
+    for (; actual < nfixargs; ++actual)
+      setnilvalue(L->top++);
+  }
+  actual -= nfixargs;  /* number of extra arguments */
+  htab = luaH_new(L, actual, 1);  /* create `arg' table */
+  for (i=0; i<actual; i++)  /* put extra arguments into `arg' table */
+    setobj2n(luaH_setnum(L, htab, i+1), L->top - actual + i);
+  /* store counter in field `n' */
+  setsvalue(&nname, luaS_newliteral(L, "n"));
+  setnvalue(luaH_set(L, htab, &nname), cast(lua_Number, actual));
+  L->top -= actual;  /* remove extra elements from the stack */
+  sethvalue(L->top, htab);
+  incr_top(L);
 }
 
 
-void luaD_callTM (lua_State *L, Closure *f, int nParams, int nResults) {
-  StkId base = L->top - nParams;
-  luaD_openstack(L, base);
-  clvalue(base) = f;
-  ttype(base) = LUA_TFUNCTION;
-  luaD_call(L, base, nResults);
+static StkId tryfuncTM (lua_State *L, StkId func) {
+  const TObject *tm = luaT_gettmbyobj(L, func, TM_CALL);
+  StkId p;
+  ptrdiff_t funcr = savestack(L, func);
+  if (!ttisfunction(tm))
+    luaG_typeerror(L, func, "call");
+  /* Open a hole inside the stack at `func' */
+  for (p = L->top; p > func; p--) setobjs2s(p, p-1);
+  incr_top(L);
+  func = restorestack(L, funcr);  /* previous call may change stack */
+  setobj2s(func, tm);  /* tag method is the new function to be called */
+  return func;
 }
 
 
-/*
-** Call a function (C or Lua). The function to be called is at *func.
-** The arguments are on the stack, right after the function.
-** When returns, the results are on the stack, starting at the original
-** function position.
-** The number of results is nResults, unless nResults=LUA_MULTRET.
-*/ 
-void luaD_call (lua_State *L, StkId func, int nResults) {
-  lua_Hook callhook;
-  StkId firstResult;
-  CallInfo ci;
-  Closure *cl;
-  if (ttype(func) != LUA_TFUNCTION) {
-    /* `func' is not a function; check the `function' tag method */
-    Closure *tm = luaT_gettmbyObj(L, func, TM_FUNCTION);
-    if (tm == NULL)
-      luaG_typeerror(L, func, "call");
-    luaD_openstack(L, func);
-    clvalue(func) = tm;  /* tag method is the new function to be called */
-    ttype(func) = LUA_TFUNCTION;
+StkId luaD_precall (lua_State *L, StkId func) {
+  LClosure *cl;
+  ptrdiff_t funcr = savestack(L, func);
+  if (!ttisfunction(func)) /* `func' is not a function? */
+    func = tryfuncTM(L, func);  /* check the `function' tag method */
+  if (L->ci + 1 == L->end_ci) luaD_growCI(L);
+  else condhardstacktests(luaD_reallocCI(L, L->size_ci));
+  cl = &clvalue(func)->l;
+  if (!cl->isC) {  /* Lua function? prepare its call */
+    CallInfo *ci;
+    Proto *p = cl->p;
+    if (p->is_vararg)  /* varargs? */
+      adjust_varargs(L, p->numparams, func+1);
+    luaD_checkstack(L, p->maxstacksize);
+    ci = ++L->ci;  /* now `enter' new function */
+    L->base = L->ci->base = restorestack(L, funcr) + 1;
+    ci->top = L->base + p->maxstacksize;
+    ci->u.l.savedpc = p->code;  /* starting point */
+    ci->u.l.tailcalls = 0;
+    ci->state = CI_SAVEDPC;
+    while (L->top < ci->top)
+      setnilvalue(L->top++);
+    L->top = ci->top;
+    return NULL;
   }
-  cl = clvalue(func);
-  ci.func = cl;
-  infovalue(func) = &ci;
-  ttype(func) = LUA_TMARK;
-  callhook = L->callhook;
-  if (callhook)
-    luaD_callHook(L, func, callhook, "call");
-  firstResult = (cl->isC ? callCclosure(L, cl, func+1) :
-                           luaV_execute(L, cl, func+1));
-  if (callhook)  /* same hook that was active at entry */
-    luaD_callHook(L, func, callhook, "return");
-  LUA_ASSERT(ttype(func) == LUA_TMARK, "invalid tag");
-  /* move results to `func' (to erase parameters and function) */
-  if (nResults == LUA_MULTRET) {
-    while (firstResult < L->top)  /* copy all results */
-      *func++ = *firstResult++;
-    L->top = func;
+  else {  /* if is a C function, call it */
+    CallInfo *ci;
+    int n;
+    luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
+    ci = ++L->ci;  /* now `enter' new function */
+    L->base = L->ci->base = restorestack(L, funcr) + 1;
+    ci->top = L->top + LUA_MINSTACK;
+    ci->state = CI_C;  /* a C function */
+    if (L->hookmask & LUA_MASKCALL)
+      luaD_callhook(L, LUA_HOOKCALL, -1);
+    lua_unlock(L);
+#ifdef LUA_COMPATUPVALUES
+    lua_pushupvalues(L);
+#endif
+    n = (*clvalue(L->base - 1)->c.f)(L);  /* do the actual call */
+    lua_lock(L);
+    return L->top - n;
   }
-  else {  /* copy at most `nResults' */
-    for (; nResults > 0 && firstResult < L->top; nResults--)
-      *func++ = *firstResult++;
-    L->top = func;
-    for (; nResults > 0; nResults--) {  /* if there are not enough results */
-      ttype(L->top) = LUA_TNIL;  /* adjust the stack */
-      incr_top;  /* must check stack space */
-    }
-  }
-  luaC_checkGC(L);
 }
 
 
-/*
-** Execute a protected call.
-*/
-struct CallS {  /* data to `f_call' */
-  StkId func;
-  int nresults;
-};
-
-static void f_call (lua_State *L, void *ud) {
-  struct CallS *c = (struct CallS *)ud;
-  luaD_call(L, c->func, c->nresults);
+static StkId callrethooks (lua_State *L, StkId firstResult) {
+  ptrdiff_t fr = savestack(L, firstResult);  /* next call may change stack */
+  luaD_callhook(L, LUA_HOOKRET, -1);
+  if (!(L->ci->state & CI_C)) {  /* Lua function? */
+    while (L->ci->u.l.tailcalls--)  /* call hook for eventual tail calls */
+      luaD_callhook(L, LUA_HOOKTAILRET, -1);
+  }
+  return restorestack(L, fr);
 }
 
 
-LUA_API int lua_call (lua_State *L, int nargs, int nresults) {
-  StkId func = L->top - (nargs+1);  /* function to be called */
-  struct CallS c;
-  int status;
-  c.func = func; c.nresults = nresults;
-  status = luaD_runprotected(L, f_call, &c);
-  if (status != 0)  /* an error occurred? */
-    L->top = func;  /* remove parameters from the stack */
-  return status;
+void luaD_poscall (lua_State *L, int wanted, StkId firstResult) { 
+  StkId res;
+  if (L->hookmask & LUA_MASKRET)
+    firstResult = callrethooks(L, firstResult);
+  res = L->base - 1;  /* res == final position of 1st result */
+  L->ci--;
+  L->base = L->ci->base;  /* restore base */
+  /* move results to correct place */
+  while (wanted != 0 && firstResult < L->top) {
+    setobjs2s(res++, firstResult++);
+    wanted--;
+  }
+  while (wanted-- > 0)
+    setnilvalue(res++);
+  L->top = res;
 }
 
 
 /*
-** Execute a protected parser.
-*/
-struct ParserS {  /* data to `f_parser' */
-  ZIO *z;
-  int bin;
-};
-
-static void f_parser (lua_State *L, void *ud) {
-  struct ParserS *p = (struct ParserS *)ud;
-  Proto *tf = p->bin ? luaU_undump(L, p->z) : luaY_parser(L, p->z);
-  luaV_Lclosure(L, tf, 0);
+** Call a function (C or Lua). The function to be called is at *func.
+** The arguments are on the stack, right after the function.
+** When returns, all the results are on the stack, starting at the original
+** function position.
+*/ 
+void luaD_call (lua_State *L, StkId func, int nResults) {
+  StkId firstResult;
+  lua_assert(!(L->ci->state & CI_CALLING));
+  if (++L->nCcalls >= LUA_MAXCCALLS) {
+    if (L->nCcalls == LUA_MAXCCALLS)
+      luaG_runerror(L, "C stack overflow");
+    else if (L->nCcalls >= (LUA_MAXCCALLS + (LUA_MAXCCALLS>>3)))
+      luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
+  }
+  firstResult = luaD_precall(L, func);
+  if (firstResult == NULL)  /* is a Lua function? */
+    firstResult = luaV_execute(L);  /* call it */
+  luaD_poscall(L, nResults, firstResult);
+  L->nCcalls--;
+  luaC_checkGC(L);
 }
 
 
-static int protectedparser (lua_State *L, ZIO *z, int bin) {
-  struct ParserS p;
-  unsigned long old_blocks;
-  int status;
-  p.z = z; p.bin = bin;
-  /* before parsing, give a (good) chance to GC */
-  if (L->nblocks/8 >= L->GCthreshold/10)
-    luaC_collectgarbage(L);
-  old_blocks = L->nblocks;
-  status = luaD_runprotected(L, f_parser, &p);
-  if (status == 0) {
-    /* add new memory to threshold (as it probably will stay) */
-    L->GCthreshold += (L->nblocks - old_blocks);
+static void resume (lua_State *L, void *ud) {
+  StkId firstResult;
+  int nargs = *cast(int *, ud);
+  CallInfo *ci = L->ci;
+  if (ci == L->base_ci) {  /* no activation record? */
+    if (nargs >= L->top - L->base)
+      luaG_runerror(L, "cannot resume dead coroutine");
+    luaD_precall(L, L->top - (nargs + 1));  /* start coroutine */
   }
-  else if (status == LUA_ERRRUN)  /* an error occurred: correct error code */
-    status = LUA_ERRSYNTAX;
-  return status;
+  else if (ci->state & CI_YIELD) {  /* inside a yield? */
+    if (ci->state & CI_C) {  /* `common' yield? */
+      /* finish interrupted execution of `OP_CALL' */
+      int nresults;
+      lua_assert((ci-1)->state & CI_SAVEDPC);
+      lua_assert(GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_CALL ||
+                 GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_TAILCALL);
+      nresults = GETARG_C(*((ci-1)->u.l.savedpc - 1)) - 1;
+      luaD_poscall(L, nresults, L->top - nargs);  /* complete it */
+      if (nresults >= 0) L->top = L->ci->top;
+    }
+    else {  /* yielded inside a hook: just continue its execution */
+      ci->state &= ~CI_YIELD;
+    }
+  }
+  else
+    luaG_runerror(L, "cannot resume non-suspended coroutine");
+  firstResult = luaV_execute(L);
+  if (firstResult != NULL)   /* return? */
+    luaD_poscall(L, LUA_MULTRET, firstResult);  /* finalize this coroutine */
 }
 
 
-static int parse_file (lua_State *L, const char *filename) {
-  ZIO z;
+LUA_API int lua_resume (lua_State *L, int nargs) {
   int status;
-  int bin;  /* flag for file mode */
-  int c;    /* look ahead char */
-  FILE *f = (filename == NULL) ? stdin : fopen(filename, "r");
-  if (f == NULL) return LUA_ERRFILE;  /* unable to open file */
-  c = fgetc(f);
-  ungetc(c, f);
-  bin = (c == ID_CHUNK);
-  if (bin && f != stdin) {
-    f = freopen(filename, "rb", f);  /* set binary mode */
-    if (f == NULL) return LUA_ERRFILE;  /* unable to reopen file */
+  lu_byte old_allowhooks;
+  lua_lock(L);
+  old_allowhooks = L->allowhook;
+  lua_assert(L->errfunc == 0 && L->nCcalls == 0);
+  status = luaD_rawrunprotected(L, resume, &nargs);
+  if (status != 0) {  /* error? */
+    L->ci = L->base_ci;  /* go back to initial level */
+    L->base = L->ci->base;
+    L->nCcalls = 0;
+    luaF_close(L, L->base);  /* close eventual pending closures */
+    seterrorobj(L, status, L->base);
+    L->allowhook = old_allowhooks;
+    restore_stack_limit(L);
   }
-  lua_pushstring(L, "@");
-  lua_pushstring(L, (filename == NULL) ? "(stdin)" : filename);
-  lua_concat(L, 2);
-  c = lua_gettop(L);
-  filename = lua_tostring(L, c);  /* filename = '@'..filename */
-  luaZ_Fopen(&z, f, filename);
-  status = protectedparser(L, &z, bin);
-  lua_remove(L, c);  /* remove `filename' from the stack */
-  if (f != stdin)
-    fclose(f);
-  return status;
-}
-
-
-LUA_API int lua_dofile (lua_State *L, const char *filename) {
-  int status = parse_file(L, filename);
-  if (status == 0)  /* parse OK? */
-    status = lua_call(L, 0, LUA_MULTRET);  /* call main */
+  lua_unlock(L);
   return status;
 }
 
 
-static int parse_buffer (lua_State *L, const char *buff, size_t size,
-                         const char *name) {
-  ZIO z;
-  if (!name) name = "?";
-  luaZ_mopen(&z, buff, size, name);
-  return protectedparser(L, &z, buff[0]==ID_CHUNK);
+LUA_API int lua_yield (lua_State *L, int nresults) {
+  CallInfo *ci;
+  lua_lock(L);
+  ci = L->ci;
+  if (L->nCcalls > 0)
+    luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
+  if (ci->state & CI_C) {  /* usual yield */
+    if ((ci-1)->state & CI_C)
+      luaG_runerror(L, "cannot yield a C function");
+    if (L->top - nresults > L->base) {  /* is there garbage in the stack? */
+      int i;
+      for (i=0; i<nresults; i++)  /* move down results */
+        setobjs2s(L->base + i, L->top - nresults + i);
+      L->top = L->base + nresults;
+    }
+  } /* else it's an yield inside a hook: nothing to do */
+  ci->state |= CI_YIELD;
+  lua_unlock(L);
+  return -1;
 }
 
 
-LUA_API int lua_dobuffer (lua_State *L, const char *buff, size_t size, const char *name) {
-  int status = parse_buffer(L, buff, size, name);
-  if (status == 0)  /* parse OK? */
-    status = lua_call(L, 0, LUA_MULTRET);  /* call main */
+int luaD_pcall (lua_State *L, Pfunc func, void *u,
+                ptrdiff_t old_top, ptrdiff_t ef) {
+  int status;
+  unsigned short oldnCcalls = L->nCcalls;
+  ptrdiff_t old_ci = saveci(L, L->ci);
+  lu_byte old_allowhooks = L->allowhook;
+  ptrdiff_t old_errfunc = L->errfunc;
+  L->errfunc = ef;
+  status = luaD_rawrunprotected(L, func, u);
+  if (status != 0) {  /* an error occurred? */
+    StkId oldtop = restorestack(L, old_top);
+    luaF_close(L, oldtop);  /* close eventual pending closures */
+    seterrorobj(L, status, oldtop);
+    L->nCcalls = oldnCcalls;
+    L->ci = restoreci(L, old_ci);
+    L->base = L->ci->base;
+    L->allowhook = old_allowhooks;
+    restore_stack_limit(L);
+  }
+  L->errfunc = old_errfunc;
   return status;
 }
 
 
-LUA_API int lua_dostring (lua_State *L, const char *str) {
-  return lua_dobuffer(L, str, strlen(str), str);
-}
-
 
 /*
-** {======================================================
-** Error-recover functions (based on long jumps)
-** =======================================================
+** Execute a protected parser.
 */
-
-/* chain list of long jump buffers */
-struct lua_longjmp {
-  jmp_buf b;
-  struct lua_longjmp *previous;
-  volatile int status;  /* error code */
+struct SParser {  /* data to `f_parser' */
+  ZIO *z;
+  Mbuffer buff;  /* buffer to be used by the scanner */
+  int bin;
 };
 
-
-static void message (lua_State *L, const char *s) {
-  const TObject *em = luaH_getglobal(L, LUA_ERRORMESSAGE);
-  if (ttype(em) == LUA_TFUNCTION) {
-    *L->top = *em;
-    incr_top;
-    lua_pushstring(L, s);
-    luaD_call(L, L->top-2, 0);
-  }
-}
-
-
-/*
-** Reports an error, and jumps up to the available recovery label
-*/
-LUA_API void lua_error (lua_State *L, const char *s) {
-  if (s) message(L, s);
-  luaD_breakrun(L, LUA_ERRRUN);
-}
-
-
-void luaD_breakrun (lua_State *L, int errcode) {
-  if (L->errorJmp) {
-    L->errorJmp->status = errcode;
-    longjmp(L->errorJmp->b, 1);
-  }
-  else {
-    if (errcode != LUA_ERRMEM)
-      message(L, "unable to recover; exiting\n");
-    exit(EXIT_FAILURE);
-  }
+static void f_parser (lua_State *L, void *ud) {
+  struct SParser *p;
+  Proto *tf;
+  Closure *cl;
+  luaC_checkGC(L);
+  p = cast(struct SParser *, ud);
+  tf = p->bin ? luaU_undump(L, p->z, &p->buff) : luaY_parser(L, p->z, &p->buff);
+  cl = luaF_newLclosure(L, 0, gt(L));
+  cl->l.p = tf;
+  setclvalue(L->top, cl);
+  incr_top(L);
 }
 
 
-int luaD_runprotected (lua_State *L, void (*f)(lua_State *, void *), void *ud) {
-  StkId oldCbase = L->Cbase;
-  StkId oldtop = L->top;
-  struct lua_longjmp lj;
-  int allowhooks = L->allowhooks;
-  lj.status = 0;
-  lj.previous = L->errorJmp;  /* chain new error handler */
-  L->errorJmp = &lj;
-  if (setjmp(lj.b) == 0)
-    (*f)(L, ud);
-  else {  /* an error occurred: restore the state */
-    L->allowhooks = allowhooks;
-    L->Cbase = oldCbase;
-    L->top = oldtop;
-    restore_stack_limit(L);
+int luaD_protectedparser (lua_State *L, ZIO *z, int bin) {
+  struct SParser p;
+  int status;
+  ptrdiff_t oldtopr = savestack(L, L->top);  /* save current top */
+  p.z = z; p.bin = bin;
+  luaZ_initbuffer(L, &p.buff);
+  status = luaD_rawrunprotected(L, f_parser, &p);
+  luaZ_freebuffer(L, &p.buff);
+  if (status != 0) {  /* error? */
+    StkId oldtop = restorestack(L, oldtopr);
+    seterrorobj(L, status, oldtop);
   }
-  L->errorJmp = lj.previous;  /* restore old error handler */
-  return lj.status;
+  return status;
 }
 
-/* }====================================================== */
 
diff --git a/src/ldo.h b/src/ldo.h
index 3fba1f56..2a61bf5b 100644
--- a/src/ldo.h
+++ b/src/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 1.28 2000/10/06 12:45:25 roberto Exp $
+** $Id: ldo.h,v 1.56 2002/12/04 17:29:32 roberto Exp $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -10,24 +10,51 @@
 
 #include "lobject.h"
 #include "lstate.h"
+#include "lzio.h"
 
 
 /*
-** macro to increment stack top.
-** There must be always an empty slot at the L->stack.top
-*/
-#define incr_top {if (L->top == L->stack_last) luaD_checkstack(L, 1); L->top++;}
+** macro to control inclusion of some hard tests on stack reallocation
+*/ 
+#ifndef HARDSTACKTESTS
+#define condhardstacktests(x)	{ /* empty */ }
+#else
+#define condhardstacktests(x)	x
+#endif
 
 
-void luaD_init (lua_State *L, int stacksize);
-void luaD_adjusttop (lua_State *L, StkId base, int extra);
-void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook);
-void luaD_call (lua_State *L, StkId func, int nResults);
-void luaD_callTM (lua_State *L, Closure *f, int nParams, int nResults);
-void luaD_checkstack (lua_State *L, int n);
+#define luaD_checkstack(L,n)	\
+  if ((char *)L->stack_last - (char *)L->top <= (n)*(int)sizeof(TObject)) \
+    luaD_growstack(L, n); \
+  else condhardstacktests(luaD_reallocstack(L, L->stacksize));
+
+
+#define incr_top(L) {luaD_checkstack(L,1); L->top++;}
 
-void luaD_breakrun (lua_State *L, int errcode);
-int luaD_runprotected (lua_State *L, void (*f)(lua_State *, void *), void *ud);
+#define savestack(L,p)		((char *)(p) - (char *)L->stack)
+#define restorestack(L,n)	((TObject *)((char *)L->stack + (n)))
+
+#define saveci(L,p)		((char *)(p) - (char *)L->base_ci)
+#define restoreci(L,n)		((CallInfo *)((char *)L->base_ci + (n)))
+
+
+/* type of protected functions, to be ran by `runprotected' */
+typedef void (*Pfunc) (lua_State *L, void *ud);
+
+void luaD_resetprotection (lua_State *L);
+int luaD_protectedparser (lua_State *L, ZIO *z, int bin);
+void luaD_callhook (lua_State *L, int event, int line);
+StkId luaD_precall (lua_State *L, StkId func);
+void luaD_call (lua_State *L, StkId func, int nResults);
+int luaD_pcall (lua_State *L, Pfunc func, void *u,
+                ptrdiff_t oldtop, ptrdiff_t ef);
+void luaD_poscall (lua_State *L, int wanted, StkId firstResult);
+void luaD_reallocCI (lua_State *L, int newsize);
+void luaD_reallocstack (lua_State *L, int newsize);
+void luaD_growstack (lua_State *L, int n);
+
+void luaD_throw (lua_State *L, int errcode);
+int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
 
 
 #endif
diff --git a/src/ldump.c b/src/ldump.c
new file mode 100644
index 00000000..234b011f
--- /dev/null
+++ b/src/ldump.c
@@ -0,0 +1,170 @@
+/*
+** $Id: ldump.c,v 1.4 2003/02/11 23:52:12 lhf Exp $
+** save bytecodes
+** See Copyright Notice in lua.h
+*/
+
+#include <stddef.h>
+
+#define ldump_c
+
+#include "lua.h"
+
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lstate.h"
+#include "lundump.h"
+
+#define DumpVector(b,n,size,D)	DumpBlock(b,(n)*(size),D)
+#define DumpLiteral(s,D)	DumpBlock("" s,(sizeof(s))-1,D)
+
+typedef struct {
+ lua_State* L;
+ lua_Chunkwriter write;
+ void* data;
+} DumpState;
+
+static void DumpBlock(const void* b, size_t size, DumpState* D)
+{
+ lua_unlock(D->L);
+ (*D->write)(D->L,b,size,D->data);
+ lua_lock(D->L);
+}
+
+static void DumpByte(int y, DumpState* D)
+{
+ char x=(char)y;
+ DumpBlock(&x,sizeof(x),D);
+}
+
+static void DumpInt(int x, DumpState* D)
+{
+ DumpBlock(&x,sizeof(x),D);
+}
+
+static void DumpSize(size_t x, DumpState* D)
+{
+ DumpBlock(&x,sizeof(x),D);
+}
+
+static void DumpNumber(lua_Number x, DumpState* D)
+{
+ DumpBlock(&x,sizeof(x),D);
+}
+
+static void DumpString(TString* s, DumpState* D)
+{
+ if (s==NULL || getstr(s)==NULL)
+  DumpSize(0,D);
+ else
+ {
+  size_t size=s->tsv.len+1;		/* include trailing '\0' */
+  DumpSize(size,D);
+  DumpBlock(getstr(s),size,D);
+ }
+}
+
+static void DumpCode(const Proto* f, DumpState* D)
+{
+ DumpInt(f->sizecode,D);
+ DumpVector(f->code,f->sizecode,sizeof(*f->code),D);
+}
+
+static void DumpLocals(const Proto* f, DumpState* D)
+{
+ int i,n=f->sizelocvars;
+ DumpInt(n,D);
+ for (i=0; i<n; i++)
+ {
+  DumpString(f->locvars[i].varname,D);
+  DumpInt(f->locvars[i].startpc,D);
+  DumpInt(f->locvars[i].endpc,D);
+ }
+}
+
+static void DumpLines(const Proto* f, DumpState* D)
+{
+ DumpInt(f->sizelineinfo,D);
+ DumpVector(f->lineinfo,f->sizelineinfo,sizeof(*f->lineinfo),D);
+}
+
+static void DumpUpvalues(const Proto* f, DumpState* D)
+{
+ int i,n=f->sizeupvalues;
+ DumpInt(n,D);
+ for (i=0; i<n; i++) DumpString(f->upvalues[i],D);
+}
+
+static void DumpFunction(const Proto* f, const TString* p, DumpState* D);
+
+static void DumpConstants(const Proto* f, DumpState* D)
+{
+ int i,n;
+ DumpInt(n=f->sizek,D);
+ for (i=0; i<n; i++)
+ {
+  const TObject* o=&f->k[i];
+  DumpByte(ttype(o),D);
+  switch (ttype(o))
+  {
+   case LUA_TNUMBER:
+	DumpNumber(nvalue(o),D);
+	break;
+   case LUA_TSTRING:
+	DumpString(tsvalue(o),D);
+	break;
+   case LUA_TNIL:
+	break;
+   default:
+	lua_assert(0);			/* cannot happen */
+	break;
+  }
+ }
+ DumpInt(n=f->sizep,D);
+ for (i=0; i<n; i++) DumpFunction(f->p[i],f->source,D);
+}
+
+static void DumpFunction(const Proto* f, const TString* p, DumpState* D)
+{
+ DumpString((f->source==p) ? NULL : f->source,D);
+ DumpInt(f->lineDefined,D);
+ DumpByte(f->nups,D);
+ DumpByte(f->numparams,D);
+ DumpByte(f->is_vararg,D);
+ DumpByte(f->maxstacksize,D);
+ DumpLines(f,D);
+ DumpLocals(f,D);
+ DumpUpvalues(f,D);
+ DumpConstants(f,D);
+ DumpCode(f,D);
+}
+
+static void DumpHeader(DumpState* D)
+{
+ DumpLiteral(LUA_SIGNATURE,D);
+ DumpByte(VERSION,D);
+ DumpByte(luaU_endianness(),D);
+ DumpByte(sizeof(int),D);
+ DumpByte(sizeof(size_t),D);
+ DumpByte(sizeof(Instruction),D);
+ DumpByte(SIZE_OP,D);
+ DumpByte(SIZE_A,D);
+ DumpByte(SIZE_B,D);
+ DumpByte(SIZE_C,D);
+ DumpByte(sizeof(lua_Number),D);
+ DumpNumber(TEST_NUMBER,D);
+}
+
+/*
+** dump function as precompiled chunk
+*/
+void luaU_dump (lua_State* L, const Proto* Main, lua_Chunkwriter w, void* data)
+{
+ DumpState D;
+ D.L=L;
+ D.write=w;
+ D.data=data;
+ DumpHeader(&D);
+ DumpFunction(Main,NULL,&D);
+}
+
diff --git a/src/lfunc.c b/src/lfunc.c
index 6841ef71..31044fa5 100644
--- a/src/lfunc.c
+++ b/src/lfunc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.c,v 1.34 2000/10/30 12:20:29 roberto Exp $
+** $Id: lfunc.c,v 1.67 2003/03/18 12:50:04 roberto Exp $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -7,87 +7,113 @@
 
 #include <stdlib.h>
 
+#define lfunc_c
+
 #include "lua.h"
 
 #include "lfunc.h"
+#include "lgc.h"
 #include "lmem.h"
+#include "lobject.h"
 #include "lstate.h"
 
 
-#define sizeclosure(n)	((int)sizeof(Closure) + (int)sizeof(TObject)*((n)-1))
+#define sizeCclosure(n)	(cast(int, sizeof(CClosure)) + \
+                         cast(int, sizeof(TObject)*((n)-1)))
+
+#define sizeLclosure(n)	(cast(int, sizeof(LClosure)) + \
+                         cast(int, sizeof(TObject *)*((n)-1)))
+
 
 
-Closure *luaF_newclosure (lua_State *L, int nelems) {
-  int size = sizeclosure(nelems);
-  Closure *c = (Closure *)luaM_malloc(L, size);
-  c->next = L->rootcl;
-  L->rootcl = c;
-  c->mark = c;
-  c->nupvalues = nelems;
-  L->nblocks += size;
+Closure *luaF_newCclosure (lua_State *L, int nelems) {
+  Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems)));
+  luaC_link(L, valtogco(c), LUA_TFUNCTION);
+  c->c.isC = 1;
+  c->c.nupvalues = cast(lu_byte, nelems);
   return c;
 }
 
 
+Closure *luaF_newLclosure (lua_State *L, int nelems, TObject *e) {
+  Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems)));
+  luaC_link(L, valtogco(c), LUA_TFUNCTION);
+  c->l.isC = 0;
+  c->l.g = *e;
+  c->l.nupvalues = cast(lu_byte, nelems);
+  return c;
+}
+
+
+UpVal *luaF_findupval (lua_State *L, StkId level) {
+  GCObject **pp = &L->openupval;
+  UpVal *p;
+  UpVal *v;
+  while ((p = ngcotouv(*pp)) != NULL && p->v >= level) {
+    if (p->v == level) return p;
+    pp = &p->next;
+  }
+  v = luaM_new(L, UpVal);  /* not found: create a new one */
+  v->tt = LUA_TUPVAL;
+  v->marked = 1;  /* open upvalues should not be collected */
+  v->v = level;  /* current value lives in the stack */
+  v->next = *pp;  /* chain it in the proper position */
+  *pp = valtogco(v);
+  return v;
+}
+
+
+void luaF_close (lua_State *L, StkId level) {
+  UpVal *p;
+  while ((p = ngcotouv(L->openupval)) != NULL && p->v >= level) {
+    setobj(&p->value, p->v);  /* save current value (write barrier) */
+    p->v = &p->value;  /* now current value lives here */
+    L->openupval = p->next;  /* remove from `open' list */
+    luaC_link(L, valtogco(p), LUA_TUPVAL);
+  }
+}
+
+
 Proto *luaF_newproto (lua_State *L) {
   Proto *f = luaM_new(L, Proto);
-  f->knum = NULL;
-  f->nknum = 0;
-  f->kstr = NULL;
-  f->nkstr = 0;
-  f->kproto = NULL;
-  f->nkproto = 0;
+  luaC_link(L, valtogco(f), LUA_TPROTO);
+  f->k = NULL;
+  f->sizek = 0;
+  f->p = NULL;
+  f->sizep = 0;
   f->code = NULL;
-  f->ncode = 0;
+  f->sizecode = 0;
+  f->sizelineinfo = 0;
+  f->sizeupvalues = 0;
+  f->nups = 0;
+  f->upvalues = NULL;
   f->numparams = 0;
   f->is_vararg = 0;
   f->maxstacksize = 0;
-  f->marked = 0;
   f->lineinfo = NULL;
-  f->nlineinfo = 0;
-  f->nlocvars = 0;
+  f->sizelocvars = 0;
   f->locvars = NULL;
   f->lineDefined = 0;
   f->source = NULL;
-  f->next = L->rootproto;  /* chain in list of protos */
-  L->rootproto = f;
   return f;
 }
 
 
-static size_t protosize (Proto *f) {
-  return sizeof(Proto)
-       + f->nknum*sizeof(Number)
-       + f->nkstr*sizeof(TString *)
-       + f->nkproto*sizeof(Proto *)
-       + f->ncode*sizeof(Instruction)
-       + f->nlocvars*sizeof(struct LocVar)
-       + f->nlineinfo*sizeof(int);
-}
-
-
-void luaF_protook (lua_State *L, Proto *f, int pc) {
-  f->ncode = pc;  /* signal that proto was properly created */
-  L->nblocks += protosize(f);
-}
-
-
 void luaF_freeproto (lua_State *L, Proto *f) {
-  if (f->ncode > 0)  /* function was properly created? */
-    L->nblocks -= protosize(f);
-  luaM_free(L, f->code);
-  luaM_free(L, f->locvars);
-  luaM_free(L, f->kstr);
-  luaM_free(L, f->knum);
-  luaM_free(L, f->kproto);
-  luaM_free(L, f->lineinfo);
-  luaM_free(L, f);
+  luaM_freearray(L, f->code, f->sizecode, Instruction);
+  luaM_freearray(L, f->p, f->sizep, Proto *);
+  luaM_freearray(L, f->k, f->sizek, TObject);
+  luaM_freearray(L, f->lineinfo, f->sizelineinfo, int);
+  luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar);
+  luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *);
+  luaM_freelem(L, f);
 }
 
 
 void luaF_freeclosure (lua_State *L, Closure *c) {
-  L->nblocks -= sizeclosure(c->nupvalues);
-  luaM_free(L, c);
+  int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) :
+                          sizeLclosure(c->l.nupvalues);
+  luaM_free(L, c, size);
 }
 
 
@@ -97,11 +123,11 @@ void luaF_freeclosure (lua_State *L, Closure *c) {
 */
 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
   int i;
-  for (i = 0; i<f->nlocvars && f->locvars[i].startpc <= pc; i++) {
+  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
     if (pc < f->locvars[i].endpc) {  /* is variable active? */
       local_number--;
       if (local_number == 0)
-        return f->locvars[i].varname->str;
+        return getstr(f->locvars[i].varname);
     }
   }
   return NULL;  /* not found */
diff --git a/src/lfunc.h b/src/lfunc.h
index 32afbc5d..5d532507 100644
--- a/src/lfunc.h
+++ b/src/lfunc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.h,v 1.13 2000/09/29 12:42:13 roberto Exp $
+** $Id: lfunc.h,v 1.21 2003/03/18 12:50:04 roberto Exp $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -11,10 +11,11 @@
 #include "lobject.h"
 
 
-
 Proto *luaF_newproto (lua_State *L);
-void luaF_protook (lua_State *L, Proto *f, int pc);
-Closure *luaF_newclosure (lua_State *L, int nelems);
+Closure *luaF_newCclosure (lua_State *L, int nelems);
+Closure *luaF_newLclosure (lua_State *L, int nelems, TObject *e);
+UpVal *luaF_findupval (lua_State *L, StkId level);
+void luaF_close (lua_State *L, StkId level);
 void luaF_freeproto (lua_State *L, Proto *f);
 void luaF_freeclosure (lua_State *L, Closure *c);
 
diff --git a/src/lgc.c b/src/lgc.c
index f1eee9ab..4cc45e39 100644
--- a/src/lgc.c
+++ b/src/lgc.c
@@ -1,11 +1,16 @@
 /*
-** $Id: lgc.c,v 1.72+ 2000/10/26 12:47:05 roberto Exp $
+** $Id: lgc.c,v 1.171 2003/04/03 13:35:34 roberto Exp $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
 
+#include <string.h>
+
+#define lgc_c
+
 #include "lua.h"
 
+#include "ldebug.h"
 #include "ldo.h"
 #include "lfunc.h"
 #include "lgc.h"
@@ -18,336 +23,471 @@
 
 
 typedef struct GCState {
-  Hash *tmark;  /* list of marked tables to be visited */
-  Closure *cmark;  /* list of marked closures to be visited */
+  GCObject *tmark;  /* list of marked objects to be traversed */
+  GCObject *wk;  /* list of traversed key-weak tables (to be cleared) */
+  GCObject *wv;  /* list of traversed value-weak tables */
+  GCObject *wkv;  /* list of traversed key-value weak tables */
+  global_State *g;
 } GCState;
 
 
+/*
+** some userful bit tricks
+*/
+#define setbit(x,b)	((x) |= (1<<(b)))
+#define resetbit(x,b)	((x) &= cast(lu_byte, ~(1<<(b))))
+#define testbit(x,b)	((x) & (1<<(b)))
 
-static void markobject (GCState *st, TObject *o);
+#define unmark(x)	resetbit((x)->gch.marked, 0)
+#define ismarked(x)	((x)->gch.marked & ((1<<4)|1))
 
+#define stringmark(s)	setbit((s)->tsv.marked, 0)
 
-/* mark a string; marks larger than 1 cannot be changed */
-#define strmark(s)    {if ((s)->marked == 0) (s)->marked = 1;}
 
+#define isfinalized(u)		(!testbit((u)->uv.marked, 1))
+#define markfinalized(u)	resetbit((u)->uv.marked, 1)
 
 
-static void protomark (Proto *f) {
-  if (!f->marked) {
-    int i;
-    f->marked = 1;
-    strmark(f->source);
-    for (i=0; i<f->nkstr; i++)
-      strmark(f->kstr[i]);
-    for (i=0; i<f->nkproto; i++)
-      protomark(f->kproto[i]);
-    for (i=0; i<f->nlocvars; i++)  /* mark local-variable names */
-      strmark(f->locvars[i].varname);
-  }
-}
+#define KEYWEAKBIT    1
+#define VALUEWEAKBIT  2
+#define KEYWEAK         (1<<KEYWEAKBIT)
+#define VALUEWEAK       (1<<VALUEWEAKBIT)
 
 
-static void markstack (lua_State *L, GCState *st) {
-  StkId o;
-  for (o=L->stack; o<L->top; o++)
-    markobject(st, o);
-}
 
+#define markobject(st,o) { checkconsistency(o); \
+  if (iscollectable(o) && !ismarked(gcvalue(o))) reallymarkobject(st,gcvalue(o)); }
 
-static void marklock (lua_State *L, GCState *st) {
-  int i;
-  for (i=0; i<L->refSize; i++) {
-    if (L->refArray[i].st == LOCK)
-      markobject(st, &L->refArray[i].o);
+#define condmarkobject(st,o,c) { checkconsistency(o); \
+  if (iscollectable(o) && !ismarked(gcvalue(o)) && (c)) \
+    reallymarkobject(st,gcvalue(o)); }
+
+#define markvalue(st,t) { if (!ismarked(valtogco(t))) \
+		reallymarkobject(st, valtogco(t)); }
+
+
+
+static void reallymarkobject (GCState *st, GCObject *o) {
+  lua_assert(!ismarked(o));
+  setbit(o->gch.marked, 0);  /* mark object */
+  switch (o->gch.tt) {
+    case LUA_TUSERDATA: {
+      markvalue(st, gcotou(o)->uv.metatable);
+      break;
+    }
+    case LUA_TFUNCTION: {
+      gcotocl(o)->c.gclist = st->tmark;
+      st->tmark = o;
+      break;
+    }
+    case LUA_TTABLE: {
+      gcotoh(o)->gclist = st->tmark;
+      st->tmark = o;
+      break;
+    }
+    case LUA_TTHREAD: {
+      gcototh(o)->gclist = st->tmark;
+      st->tmark = o;
+      break;
+    }
+    case LUA_TPROTO: {
+      gcotop(o)->gclist = st->tmark;
+      st->tmark = o;
+      break;
+    }
+    default: lua_assert(o->gch.tt == LUA_TSTRING);
   }
 }
 
 
-static void markclosure (GCState *st, Closure *cl) {
-  if (!ismarked(cl)) {
-    if (!cl->isC)
-      protomark(cl->f.l);
-    cl->mark = st->cmark;  /* chain it for later traversal */
-    st->cmark = cl;
+static void marktmu (GCState *st) {
+  GCObject *u;
+  for (u = st->g->tmudata; u; u = u->gch.next) {
+    unmark(u);  /* may be marked, if left from previous GC */
+    reallymarkobject(st, u);
   }
 }
 
 
-static void marktagmethods (lua_State *L, GCState *st) {
-  int e;
-  for (e=0; e<TM_N; e++) {
-    int t;
-    for (t=0; t<=L->last_tag; t++) {
-      Closure *cl = luaT_gettm(L, t, e);
-      if (cl) markclosure(st, cl);
+/* move `dead' udata that need finalization to list `tmudata' */
+void luaC_separateudata (lua_State *L) {
+  GCObject **p = &G(L)->rootudata;
+  GCObject *curr;
+  GCObject *collected = NULL;  /* to collect udata with gc event */
+  GCObject **lastcollected = &collected;
+  while ((curr = *p) != NULL) {
+    lua_assert(curr->gch.tt == LUA_TUSERDATA);
+    if (ismarked(curr) || isfinalized(gcotou(curr)))
+      p = &curr->gch.next;  /* don't bother with them */
+
+    else if (fasttm(L, gcotou(curr)->uv.metatable, TM_GC) == NULL) {
+      markfinalized(gcotou(curr));  /* don't need finalization */
+      p = &curr->gch.next;
+    }
+    else {  /* must call its gc method */
+      *p = curr->gch.next;
+      curr->gch.next = NULL;  /* link `curr' at the end of `collected' list */
+      *lastcollected = curr;
+      lastcollected = &curr->gch.next;
     }
   }
+  /* insert collected udata with gc event into `tmudata' list */
+  *lastcollected = G(L)->tmudata;
+  G(L)->tmudata = collected;
 }
 
 
-static void markobject (GCState *st, TObject *o) {
-  switch (ttype(o)) {
-    case LUA_TUSERDATA:  case LUA_TSTRING:
-      strmark(tsvalue(o));
-      break;
-    case LUA_TMARK:
-      markclosure(st, infovalue(o)->func);
-      break;
-    case LUA_TFUNCTION:
-      markclosure(st, clvalue(o));
-      break;
-    case LUA_TTABLE: {
-      if (!ismarked(hvalue(o))) {
-        hvalue(o)->mark = st->tmark;  /* chain it in list of marked */
-        st->tmark = hvalue(o);
-      }
-      break;
-    }
-    default: break;  /* numbers, etc */
-  }
+static void removekey (Node *n) {
+  setnilvalue(gval(n));  /* remove corresponding value ... */
+  if (iscollectable(gkey(n)))
+    setttype(gkey(n), LUA_TNONE);  /* dead key; remove it */
 }
 
 
-static void markall (lua_State *L) {
-  GCState st;
-  st.cmark = NULL;
-  st.tmark = L->gt;  /* put table of globals in mark list */
-  L->gt->mark = NULL;
-  marktagmethods(L, &st);  /* mark tag methods */
-  markstack(L, &st); /* mark stack objects */
-  marklock(L, &st); /* mark locked objects */
-  for (;;) {  /* mark tables and closures */
-    if (st.cmark) {
-      int i;
-      Closure *f = st.cmark;  /* get first closure from list */
-      st.cmark = f->mark;  /* remove it from list */
-      for (i=0; i<f->nupvalues; i++)  /* mark its upvalues */
-        markobject(&st, &f->upvalue[i]);
+static void traversetable (GCState *st, Table *h) {
+  int i;
+  int weakkey = 0;
+  int weakvalue = 0;
+  const TObject *mode;
+  markvalue(st, h->metatable);
+  lua_assert(h->lsizenode || h->node == st->g->dummynode);
+  mode = gfasttm(st->g, h->metatable, TM_MODE);
+  if (mode && ttisstring(mode)) {  /* is there a weak mode? */
+    weakkey = (strchr(svalue(mode), 'k') != NULL);
+    weakvalue = (strchr(svalue(mode), 'v') != NULL);
+    if (weakkey || weakvalue) {  /* is really weak? */
+      GCObject **weaklist;
+      h->marked &= ~(KEYWEAK | VALUEWEAK);  /* clear bits */
+      h->marked |= cast(lu_byte, (weakkey << KEYWEAKBIT) |
+                                 (weakvalue << VALUEWEAKBIT));
+      weaklist = (weakkey && weakvalue) ? &st->wkv :
+                              (weakkey) ? &st->wk :
+                                          &st->wv;
+      h->gclist = *weaklist;  /* must be cleared after GC, ... */
+      *weaklist = valtogco(h);  /* ... so put in the appropriate list */
     }
-    else if (st.tmark) {
-      int i;
-      Hash *h = st.tmark;  /* get first table from list */
-      st.tmark = h->mark;  /* remove it from list */
-      for (i=0; i<h->size; i++) {
-        Node *n = node(h, i);
-        if (ttype(key(n)) != LUA_TNIL) {
-          if (ttype(val(n)) == LUA_TNIL)
-            luaH_remove(h, key(n));  /* dead element; try to remove it */
-          markobject(&st, &n->key);
-          markobject(&st, &n->val);
-        }
-      }
+  }
+  if (!weakvalue) {
+    i = h->sizearray;
+    while (i--)
+      markobject(st, &h->array[i]);
+  }
+  i = sizenode(h);
+  while (i--) {
+    Node *n = gnode(h, i);
+    if (!ttisnil(gval(n))) {
+      lua_assert(!ttisnil(gkey(n)));
+      condmarkobject(st, gkey(n), !weakkey);
+      condmarkobject(st, gval(n), !weakvalue);
     }
-    else break;  /* nothing else to mark */
   }
 }
 
 
-static int hasmark (const TObject *o) {
-  /* valid only for locked objects */
-  switch (o->ttype) {
-    case LUA_TSTRING: case LUA_TUSERDATA:
-      return tsvalue(o)->marked;
-    case LUA_TTABLE:
-      return ismarked(hvalue(o));
-    case LUA_TFUNCTION:
-      return ismarked(clvalue(o));
-    default:  /* number */
-      return 1;
+static void traverseproto (GCState *st, Proto *f) {
+  int i;
+  stringmark(f->source);
+  for (i=0; i<f->sizek; i++) {  /* mark literal strings */
+    if (ttisstring(f->k+i))
+      stringmark(tsvalue(f->k+i));
   }
+  for (i=0; i<f->sizeupvalues; i++)  /* mark upvalue names */
+    stringmark(f->upvalues[i]);
+  for (i=0; i<f->sizep; i++)  /* mark nested protos */
+    markvalue(st, f->p[i]);
+  for (i=0; i<f->sizelocvars; i++)  /* mark local-variable names */
+    stringmark(f->locvars[i].varname);
+  lua_assert(luaG_checkcode(f));
 }
 
 
-/* macro for internal debugging; check if a link of free refs is valid */
-#define VALIDLINK(L, st,n)      (NONEXT <= (st) && (st) < (n))
 
-static void invalidaterefs (lua_State *L) {
-  int n = L->refSize;
-  int i;
-  for (i=0; i<n; i++) {
-    struct Ref *r = &L->refArray[i];
-    if (r->st == HOLD && !hasmark(&r->o))
-      r->st = COLLECTED;
-    LUA_ASSERT((r->st == LOCK && hasmark(&r->o)) ||
-               (r->st == HOLD && hasmark(&r->o)) ||
-                r->st == COLLECTED ||
-                r->st == NONEXT ||
-               (r->st < n && VALIDLINK(L, L->refArray[r->st].st, n)),
-               "inconsistent ref table");
+static void traverseclosure (GCState *st, Closure *cl) {
+  if (cl->c.isC) {
+    int i;
+    for (i=0; i<cl->c.nupvalues; i++)  /* mark its upvalues */
+      markobject(st, &cl->c.upvalue[i]);
+  }
+  else {
+    int i;
+    lua_assert(cl->l.nupvalues == cl->l.p->nups);
+    markvalue(st, hvalue(&cl->l.g));
+    markvalue(st, cl->l.p);
+    for (i=0; i<cl->l.nupvalues; i++) {  /* mark its upvalues */
+      UpVal *u = cl->l.upvals[i];
+      if (!u->marked) {
+        markobject(st, &u->value);
+        u->marked = 1;
+      }
+    }
   }
-  LUA_ASSERT(VALIDLINK(L, L->refFree, n), "inconsistent ref table");
 }
 
 
+static void checkstacksizes (lua_State *L, StkId max) {
+  int used = L->ci - L->base_ci;  /* number of `ci' in use */
+  if (4*used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci)
+    luaD_reallocCI(L, L->size_ci/2);  /* still big enough... */
+  else condhardstacktests(luaD_reallocCI(L, L->size_ci));
+  used = max - L->stack;  /* part of stack in use */
+  if (4*used < L->stacksize && 2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize)
+    luaD_reallocstack(L, L->stacksize/2);  /* still big enough... */
+  else condhardstacktests(luaD_reallocstack(L, L->stacksize));
+}
 
-static void collectproto (lua_State *L) {
-  Proto **p = &L->rootproto;
-  Proto *next;
-  while ((next = *p) != NULL) {
-    if (next->marked) {
-      next->marked = 0;
-      p = &next->next;
-    }
-    else {
-      *p = next->next;
-      luaF_freeproto(L, next);
-    }
+
+static void traversestack (GCState *st, lua_State *L1) {
+  StkId o, lim;
+  CallInfo *ci;
+  markobject(st, gt(L1));
+  lim = L1->top;
+  for (ci = L1->base_ci; ci <= L1->ci; ci++) {
+    lua_assert(ci->top <= L1->stack_last);
+    lua_assert(ci->state & (CI_C | CI_HASFRAME | CI_SAVEDPC));
+    if (!(ci->state & CI_C) && lim < ci->top)
+      lim = ci->top;
   }
+  for (o = L1->stack; o < L1->top; o++)
+    markobject(st, o);
+  for (; o <= lim; o++)
+    setnilvalue(o);
+  checkstacksizes(L1, lim);
 }
 
 
-static void collectclosure (lua_State *L) {
-  Closure **p = &L->rootcl;
-  Closure *next;
-  while ((next = *p) != NULL) {
-    if (ismarked(next)) {
-      next->mark = next;  /* unmark */
-      p = &next->next;
+static void propagatemarks (GCState *st) {
+  while (st->tmark) {  /* traverse marked objects */
+    switch (st->tmark->gch.tt) {
+      case LUA_TTABLE: {
+        Table *h = gcotoh(st->tmark);
+        st->tmark = h->gclist;
+        traversetable(st, h);
+        break;
+      }
+      case LUA_TFUNCTION: {
+        Closure *cl = gcotocl(st->tmark);
+        st->tmark = cl->c.gclist;
+        traverseclosure(st, cl);
+        break;
+      }
+      case LUA_TTHREAD: {
+        lua_State *th = gcototh(st->tmark);
+        st->tmark = th->gclist;
+        traversestack(st, th);
+        break;
+      }
+      case LUA_TPROTO: {
+        Proto *p = gcotop(st->tmark);
+        st->tmark = p->gclist;
+        traverseproto(st, p);
+        break;
+      }
+      default: lua_assert(0);
     }
-    else {
-      *p = next->next;
-      luaF_freeclosure(L, next);
+  }
+}
+
+
+static int valismarked (const TObject *o) {
+  if (ttisstring(o))
+    stringmark(tsvalue(o));  /* strings are `values', so are never weak */
+  return !iscollectable(o) || testbit(o->value.gc->gch.marked, 0);
+}
+
+
+/*
+** clear collected keys from weaktables
+*/
+static void cleartablekeys (GCObject *l) {
+  while (l) {
+    Table *h = gcotoh(l);
+    int i = sizenode(h);
+    lua_assert(h->marked & KEYWEAK);
+    while (i--) {
+      Node *n = gnode(h, i);
+      if (!valismarked(gkey(n)))  /* key was collected? */
+        removekey(n);  /* remove entry from table */
     }
+    l = h->gclist;
   }
 }
 
 
-static void collecttable (lua_State *L) {
-  Hash **p = &L->roottable;
-  Hash *next;
-  while ((next = *p) != NULL) {
-    if (ismarked(next)) {
-      next->mark = next;  /* unmark */
-      p = &next->next;
+/*
+** clear collected values from weaktables
+*/
+static void cleartablevalues (GCObject *l) {
+  while (l) {
+    Table *h = gcotoh(l);
+    int i = h->sizearray;
+    lua_assert(h->marked & VALUEWEAK);
+    while (i--) {
+      TObject *o = &h->array[i];
+      if (!valismarked(o))  /* value was collected? */
+        setnilvalue(o);  /* remove value */
     }
-    else {
-      *p = next->next;
-      luaH_free(L, next);
+    i = sizenode(h);
+    while (i--) {
+      Node *n = gnode(h, i);
+      if (!valismarked(gval(n)))  /* value was collected? */
+        removekey(n);  /* remove entry from table */
     }
+    l = h->gclist;
   }
 }
 
 
-static void checktab (lua_State *L, stringtable *tb) {
-  if (tb->nuse < (lint32)(tb->size/4) && tb->size > 10)
-    luaS_resize(L, tb, tb->size/2);  /* table is too big */
+static void freeobj (lua_State *L, GCObject *o) {
+  switch (o->gch.tt) {
+    case LUA_TPROTO: luaF_freeproto(L, gcotop(o)); break;
+    case LUA_TFUNCTION: luaF_freeclosure(L, gcotocl(o)); break;
+    case LUA_TUPVAL: luaM_freelem(L, gcotouv(o)); break;
+    case LUA_TTABLE: luaH_free(L, gcotoh(o)); break;
+    case LUA_TTHREAD: {
+      lua_assert(gcototh(o) != L && gcototh(o) != G(L)->mainthread);
+      luaE_freethread(L, gcototh(o));
+      break;
+    }
+    case LUA_TSTRING: {
+      luaM_free(L, o, sizestring(gcotots(o)->tsv.len));
+      break;
+    }
+    case LUA_TUSERDATA: {
+      luaM_free(L, o, sizeudata(gcotou(o)->uv.len));
+      break;
+    }
+    default: lua_assert(0);
+  }
 }
 
 
-static void collectstrings (lua_State *L, int all) {
-  int i;
-  for (i=0; i<L->strt.size; i++) {  /* for each list */
-    TString **p = &L->strt.hash[i];
-    TString *next;
-    while ((next = *p) != NULL) {
-      if (next->marked && !all) {  /* preserve? */
-        if (next->marked < FIXMARK)  /* does not change FIXMARKs */
-          next->marked = 0;
-        p = &next->nexthash;
-      } 
-      else {  /* collect */
-        *p = next->nexthash;
-        L->strt.nuse--;
-        L->nblocks -= sizestring(next->len);
-        luaM_free(L, next);
-      }
+static int sweeplist (lua_State *L, GCObject **p, int limit) {
+  GCObject *curr;
+  int count = 0;  /* number of collected items */
+  while ((curr = *p) != NULL) {
+    if (curr->gch.marked > limit) {
+      unmark(curr);
+      p = &curr->gch.next;
+    }
+    else {
+      count++;
+      *p = curr->gch.next;
+      freeobj(L, curr);
     }
   }
-  checktab(L, &L->strt);
+  return count;
 }
 
 
-static void collectudata (lua_State *L, int all) {
+static void sweepstrings (lua_State *L, int all) {
   int i;
-  for (i=0; i<L->udt.size; i++) {  /* for each list */
-    TString **p = &L->udt.hash[i];
-    TString *next;
-    while ((next = *p) != NULL) {
-      LUA_ASSERT(next->marked <= 1, "udata cannot be fixed");
-      if (next->marked && !all) {  /* preserve? */
-        next->marked = 0;
-        p = &next->nexthash;
-      } 
-      else {  /* collect */
-        int tag = next->u.d.tag;
-        *p = next->nexthash;
-        next->nexthash = L->TMtable[tag].collected;  /* chain udata */
-        L->TMtable[tag].collected = next;
-        L->nblocks -= sizestring(next->len);
-        L->udt.nuse--;
-      }
-    }
+  for (i=0; i<G(L)->strt.size; i++) {  /* for each list */
+    G(L)->strt.nuse -= sweeplist(L, &G(L)->strt.hash[i], all);
   }
-  checktab(L, &L->udt);
 }
 
 
-#define MINBUFFER	256
-static void checkMbuffer (lua_State *L) {
-  if (L->Mbuffsize > MINBUFFER*2) {  /* is buffer too big? */
-    size_t newsize = L->Mbuffsize/2;  /* still larger than MINBUFFER */
-    L->nblocks += (newsize - L->Mbuffsize)*sizeof(char);
-    L->Mbuffsize = newsize;
-    luaM_reallocvector(L, L->Mbuffer, newsize, char);
+static void checkSizes (lua_State *L) {
+  /* check size of string hash */
+  if (G(L)->strt.nuse < cast(ls_nstr, G(L)->strt.size/4) &&
+      G(L)->strt.size > MINSTRTABSIZE*2)
+    luaS_resize(L, G(L)->strt.size/2);  /* table is too big */
+  /* check size of buffer */
+  if (luaZ_sizebuffer(&G(L)->buff) > LUA_MINBUFFER*2) {  /* buffer too big? */
+    size_t newsize = luaZ_sizebuffer(&G(L)->buff) / 2;
+    luaZ_resizebuffer(L, &G(L)->buff, newsize);
   }
+  G(L)->GCthreshold = 2*G(L)->nblocks;  /* new threshold */
 }
 
 
-static void callgcTM (lua_State *L, const TObject *o) {
-  Closure *tm = luaT_gettmbyObj(L, o, TM_GC);
+static void do1gcTM (lua_State *L, Udata *udata) {
+  const TObject *tm = fasttm(L, udata->uv.metatable, TM_GC);
   if (tm != NULL) {
-    int oldah = L->allowhooks;
-    L->allowhooks = 0;  /* stop debug hooks during GC tag methods */
-    luaD_checkstack(L, 2);
-    clvalue(L->top) = tm;
-    ttype(L->top) = LUA_TFUNCTION;
-    *(L->top+1) = *o;
+    setobj2s(L->top, tm);
+    setuvalue(L->top+1, udata);
     L->top += 2;
-    luaD_call(L, L->top-2, 0);
-    L->allowhooks = oldah;  /* restore hooks */
+    luaD_call(L, L->top - 2, 0);
   }
 }
 
 
-static void callgcTMudata (lua_State *L) {
-  int tag;
-  TObject o;
-  ttype(&o) = LUA_TUSERDATA;
-  L->GCthreshold = 2*L->nblocks;  /* avoid GC during tag methods */
-  for (tag=L->last_tag; tag>=0; tag--) {  /* for each tag (in reverse order) */
-    TString *udata;
-    while ((udata = L->TMtable[tag].collected) != NULL) {
-      L->TMtable[tag].collected = udata->nexthash;  /* remove it from list */
-      tsvalue(&o) = udata;
-      callgcTM(L, &o);
-      luaM_free(L, udata);
-    }
+void luaC_callGCTM (lua_State *L) {
+  lu_byte oldah = L->allowhook;
+  L->allowhook = 0;  /* stop debug hooks during GC tag methods */
+  L->top++;  /* reserve space to keep udata while runs its gc method */
+  while (G(L)->tmudata != NULL) {
+    GCObject *o = G(L)->tmudata;
+    Udata *udata = gcotou(o);
+    G(L)->tmudata = udata->uv.next;  /* remove udata from `tmudata' */
+    udata->uv.next = G(L)->rootudata;  /* return it to `root' list */
+    G(L)->rootudata = o;
+    setuvalue(L->top - 1, udata);  /* keep a reference to it */
+    unmark(o);
+    markfinalized(udata);
+    do1gcTM(L, udata);
   }
+  L->top--;
+  L->allowhook = oldah;  /* restore hooks */
 }
 
 
-void luaC_collect (lua_State *L, int all) {
-  collectudata(L, all);
-  callgcTMudata(L);
-  collectstrings(L, all);
-  collecttable(L);
-  collectproto(L);
-  collectclosure(L);
+void luaC_sweep (lua_State *L, int all) {
+  if (all) all = 256;  /* larger than any mark */
+  sweeplist(L, &G(L)->rootudata, all);
+  sweepstrings(L, all);
+  sweeplist(L, &G(L)->rootgc, all);
+}
+
+
+/* mark root set */
+static void markroot (GCState *st, lua_State *L) {
+  global_State *g = st->g;
+  markobject(st, defaultmeta(L));
+  markobject(st, registry(L));
+  traversestack(st, g->mainthread);
+  if (L != g->mainthread)  /* another thread is running? */
+    markvalue(st, L);  /* cannot collect it */
+}
+
+
+static void mark (lua_State *L) {
+  GCState st;
+  GCObject *wkv;
+  st.g = G(L);
+  st.tmark = NULL;
+  st.wkv = st.wk = st.wv = NULL;
+  markroot(&st, L);
+  propagatemarks(&st);  /* mark all reachable objects */
+  cleartablevalues(st.wkv);
+  cleartablevalues(st.wv);
+  wkv = st.wkv;  /* keys must be cleared after preserving udata */
+  st.wkv = NULL;
+  st.wv = NULL;
+  luaC_separateudata(L);  /* separate userdata to be preserved */
+  marktmu(&st);  /* mark `preserved' userdata */
+  propagatemarks(&st);  /* remark, to propagate `preserveness' */
+  cleartablekeys(wkv);
+  /* `propagatemarks' may resuscitate some weak tables; clear them too */
+  cleartablekeys(st.wk);
+  cleartablevalues(st.wv);
+  cleartablekeys(st.wkv);
+  cleartablevalues(st.wkv);
 }
 
 
 void luaC_collectgarbage (lua_State *L) {
-  markall(L);
-  invalidaterefs(L);  /* check unlocked references */
-  luaC_collect(L, 0);
-  checkMbuffer(L);
-  L->GCthreshold = 2*L->nblocks;  /* set new threshold */
-  callgcTM(L, &luaO_nilobject);
+  mark(L);
+  luaC_sweep(L, 0);
+  checkSizes(L);
+  luaC_callGCTM(L);
 }
 
 
-void luaC_checkGC (lua_State *L) {
-  if (L->nblocks >= L->GCthreshold)
-    luaC_collectgarbage(L);
+void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
+  o->gch.next = G(L)->rootgc;
+  G(L)->rootgc = o;
+  o->gch.marked = 0;
+  o->gch.tt = tt;
 }
 
diff --git a/src/lgc.h b/src/lgc.h
index 09b66a2b..6ab6c917 100644
--- a/src/lgc.h
+++ b/src/lgc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.h,v 1.9 2001/02/02 16:23:20 roberto Exp $
+** $Id: lgc.h,v 1.19 2003/02/28 19:45:15 roberto Exp $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -11,9 +11,15 @@
 #include "lobject.h"
 
 
-void luaC_collect (lua_State *L, int all);
+#define luaC_checkGC(L) { lua_assert(!(L->ci->state & CI_CALLING)); \
+	if (G(L)->nblocks >= G(L)->GCthreshold) luaC_collectgarbage(L); }
+
+
+void luaC_separateudata (lua_State *L);
+void luaC_callGCTM (lua_State *L);
+void luaC_sweep (lua_State *L, int all);
 void luaC_collectgarbage (lua_State *L);
-void luaC_checkGC (lua_State *L);
+void luaC_link (lua_State *L, GCObject *o, lu_byte tt);
 
 
 #endif
diff --git a/src/lib/Makefile b/src/lib/Makefile
index 081b8867..3c6c07ab 100644
--- a/src/lib/Makefile
+++ b/src/lib/Makefile
@@ -4,17 +4,16 @@ LUA= ../..
 
 include $(LUA)/config
 
-# actually only used in liolib.c
-EXTRA_DEFS= $(POPEN)
+EXTRA_DEFS= $(POPEN) $(TMPNAM) $(DEGREES) $(LOADLIB)
 
-OBJS= lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o lstrlib.o
-SRCS= lauxlib.c lbaselib.c ldblib.c liolib.c lmathlib.c lstrlib.c
+OBJS= lauxlib.o lbaselib.o ldblib.o liolib.o lmathlib.o ltablib.o lstrlib.o loadlib.o
+SRCS= lauxlib.c lbaselib.c ldblib.c liolib.c lmathlib.c ltablib.c lstrlib.c loadlib.c
 
 T= $(LIB)/liblualib.a
 
-all: $T
+all:	$T
 
-$T: $(OBJS)
+$T:	$(OBJS)
 	$(AR) $@ $(OBJS)
 	$(RANLIB) $@
 
diff --git a/src/lib/README b/src/lib/README
index c04a12e2..c5600b8e 100644
--- a/src/lib/README
+++ b/src/lib/README
@@ -1,6 +1,8 @@
 This is the standard Lua library.
-It is implemented entirely on top of the official Lua API as declared in lua.h,
-using lauxlib.c, which contains several useful functions for writing libraries. 
-We encourage developers to use lauxlib.c in their own libraries.
+
 The code of the standard library can be read as an example of how to export
-C functions to Lua.
+C functions to Lua. The easiest library to read is lmathlib.c.
+
+The library is implemented entirely on top of the official Lua API as declared
+in lua.h, using lauxlib.c, which contains several useful functions for writing
+libraries. We encourage developers to use lauxlib.c in their own libraries.
diff --git a/src/lib/lauxlib.c b/src/lib/lauxlib.c
index 4bdaeeff..ee2d1339 100644
--- a/src/lib/lauxlib.c
+++ b/src/lib/lauxlib.c
@@ -1,25 +1,101 @@
 /*
-** $Id: lauxlib.c,v 1.43 2000/10/30 13:07:48 roberto Exp $
+** $Id: lauxlib.c,v 1.100 2003/04/07 14:35:00 roberto Exp $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
 
 
+#include <ctype.h>
+#include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
 
+
 /* This file uses only the official API of Lua.
 ** Any function declared here could be written as an application function.
-** With care, these functions can be used by other libraries.
 */
 
+#define lauxlib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
-#include "luadebug.h"
 
 
+/* number of prereserved references (for internal use) */
+#define RESERVED_REFS	2
+
+/* reserved references */
+#define FREELIST_REF	1	/* free list of references */
+#define ARRAYSIZE_REF	2	/* array sizes */
+
+
+/* convert a stack index to positive */
+#define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \
+					lua_gettop(L) + (i) + 1)
+
+
+/*
+** {======================================================
+** Error-report functions
+** =======================================================
+*/
+
+
+LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {
+  lua_Debug ar;
+  lua_getstack(L, 0, &ar);
+  lua_getinfo(L, "n", &ar);
+  if (strcmp(ar.namewhat, "method") == 0) {
+    narg--;  /* do not count `self' */
+    if (narg == 0)  /* error is in the self argument itself? */
+      return luaL_error(L, "calling `%s' on bad self (%s)", ar.name, extramsg);
+  }
+  if (ar.name == NULL)
+    ar.name = "?";
+  return luaL_error(L, "bad argument #%d to `%s' (%s)",
+                        narg, ar.name, extramsg);
+}
+
+
+LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname) {
+  const char *msg = lua_pushfstring(L, "%s expected, got %s",
+                                    tname, lua_typename(L, lua_type(L,narg)));
+  return luaL_argerror(L, narg, msg);
+}
+
+
+static void tag_error (lua_State *L, int narg, int tag) {
+  luaL_typerror(L, narg, lua_typename(L, tag)); 
+}
+
+
+LUALIB_API void luaL_where (lua_State *L, int level) {
+  lua_Debug ar;
+  if (lua_getstack(L, level, &ar)) {  /* check function at level */
+    lua_getinfo(L, "Snl", &ar);  /* get info about it */
+    if (ar.currentline > 0) {  /* is there info? */
+      lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
+      return;
+    }
+  }
+  lua_pushliteral(L, "");  /* else, no information available... */
+}
+
+
+LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
+  va_list argp;
+  va_start(argp, fmt);
+  luaL_where(L, 1);
+  lua_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  lua_concat(L, 2);
+  return lua_error(L);
+}
+
+/* }====================================================== */
+
 
 LUALIB_API int luaL_findstring (const char *name, const char *const list[]) {
   int i;
@@ -29,34 +105,55 @@ LUALIB_API int luaL_findstring (const char *name, const char *const list[]) {
   return -1;  /* name not found */
 }
 
-LUALIB_API void luaL_argerror (lua_State *L, int narg, const char *extramsg) {
-  lua_Debug ar;
-  lua_getstack(L, 0, &ar);
-  lua_getinfo(L, "n", &ar);
-  if (ar.name == NULL)
-    ar.name = "?";
-  luaL_verror(L, "bad argument #%d to `%.50s' (%.100s)",
-              narg, ar.name, extramsg);
+
+LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
+  lua_pushstring(L, tname);
+  lua_rawget(L, LUA_REGISTRYINDEX);  /* get registry.name */
+  if (!lua_isnil(L, -1))  /* name already in use? */
+    return 0;  /* leave previous value on top, but return 0 */
+  lua_pop(L, 1);
+  lua_newtable(L);  /* create metatable */
+  lua_pushstring(L, tname);
+  lua_pushvalue(L, -2);
+  lua_rawset(L, LUA_REGISTRYINDEX);  /* registry.name = metatable */
+  lua_pushvalue(L, -1);
+  lua_pushstring(L, tname);
+  lua_rawset(L, LUA_REGISTRYINDEX);  /* registry[metatable] = name */
+  return 1;
 }
 
 
-static void type_error (lua_State *L, int narg, int t) {
-  char buff[50];
-  sprintf(buff, "%.8s expected, got %.8s", lua_typename(L, t),
-                                           lua_typename(L, lua_type(L, narg)));
-  luaL_argerror(L, narg, buff);
+LUALIB_API void  luaL_getmetatable (lua_State *L, const char *tname) {
+  lua_pushstring(L, tname);
+  lua_rawget(L, LUA_REGISTRYINDEX);
+}
+
+
+LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
+  const char *tn;
+  if (!lua_getmetatable(L, ud)) return NULL;  /* no metatable? */
+  lua_rawget(L, LUA_REGISTRYINDEX);  /* get registry[metatable] */
+  tn = lua_tostring(L, -1);
+  if (tn && (strcmp(tn, tname) == 0)) {
+    lua_pop(L, 1);
+    return lua_touserdata(L, ud);
+  }
+  else {
+    lua_pop(L, 1);
+    return NULL;
+  }
 }
 
 
 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {
-  if (space > lua_stackspace(L))
-    luaL_verror(L, "stack overflow (%.30s)", mes);
+  if (!lua_checkstack(L, space))
+    luaL_error(L, "stack overflow (%s)", mes);
 }
 
 
-LUALIB_API void luaL_checktype(lua_State *L, int narg, int t) {
+LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {
   if (lua_type(L, narg) != t)
-    type_error(L, narg, t);
+    tag_error(L, narg, t);
 }
 
 
@@ -66,55 +163,164 @@ LUALIB_API void luaL_checkany (lua_State *L, int narg) {
 }
 
 
-LUALIB_API const char *luaL_check_lstr (lua_State *L, int narg, size_t *len) {
+LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {
   const char *s = lua_tostring(L, narg);
-  if (!s) type_error(L, narg, LUA_TSTRING);
+  if (!s) tag_error(L, narg, LUA_TSTRING);
   if (len) *len = lua_strlen(L, narg);
   return s;
 }
 
 
-LUALIB_API const char *luaL_opt_lstr (lua_State *L, int narg, const char *def, size_t *len) {
-  if (lua_isnull(L, narg)) {
+LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,
+                                        const char *def, size_t *len) {
+  if (lua_isnoneornil(L, narg)) {
     if (len)
       *len = (def ? strlen(def) : 0);
     return def;
   }
-  else return luaL_check_lstr(L, narg, len);
+  else return luaL_checklstring(L, narg, len);
 }
 
 
-LUALIB_API double luaL_check_number (lua_State *L, int narg) {
-  double d = lua_tonumber(L, narg);
+LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {
+  lua_Number d = lua_tonumber(L, narg);
   if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
-    type_error(L, narg, LUA_TNUMBER);
+    tag_error(L, narg, LUA_TNUMBER);
   return d;
 }
 
 
-LUALIB_API double luaL_opt_number (lua_State *L, int narg, double def) {
-  if (lua_isnull(L, narg)) return def;
-  else return luaL_check_number(L, narg);
+LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {
+  if (lua_isnoneornil(L, narg)) return def;
+  else return luaL_checknumber(L, narg);
 }
 
 
-LUALIB_API void luaL_openlib (lua_State *L, const struct luaL_reg *l, int n) {
-  int i;
-  for (i=0; i<n; i++)
-    lua_register(L, l[i].name, l[i].func);
+LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
+  if (!lua_getmetatable(L, obj))  /* no metatable? */
+    return 0;
+  lua_pushstring(L, event);
+  lua_rawget(L, -2);
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 2);  /* remove metatable and metafield */
+    return 0;
+  }
+  else {
+    lua_remove(L, -2);  /* remove only metatable */
+    return 1;
+  }
 }
 
 
-LUALIB_API void luaL_verror (lua_State *L, const char *fmt, ...) {
-  char buff[500];
-  va_list argp;
-  va_start(argp, fmt);
-  vsprintf(buff, fmt, argp);
-  va_end(argp);
-  lua_error(L, buff);
+LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
+  obj = abs_index(L, obj);
+  if (!luaL_getmetafield(L, obj, event))  /* no metafield? */
+    return 0;
+  lua_pushvalue(L, obj);
+  lua_call(L, 1, 1);
+  return 1;
 }
 
 
+LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
+                              const luaL_reg *l, int nup) {
+  if (libname) {
+    lua_pushstring(L, libname);
+    lua_gettable(L, LUA_GLOBALSINDEX);  /* check whether lib already exists */
+    if (lua_isnil(L, -1)) {  /* no? */
+      lua_pop(L, 1);
+      lua_newtable(L);  /* create it */
+      lua_pushstring(L, libname);
+      lua_pushvalue(L, -2);
+      lua_settable(L, LUA_GLOBALSINDEX);  /* register it with given name */
+    }
+    lua_insert(L, -(nup+1));  /* move library table to below upvalues */
+  }
+  for (; l->name; l++) {
+    int i;
+    lua_pushstring(L, l->name);
+    for (i=0; i<nup; i++)  /* copy upvalues to the top */
+      lua_pushvalue(L, -(nup+1));
+    lua_pushcclosure(L, l->func, nup);
+    lua_settable(L, -(nup+3));
+  }
+  lua_pop(L, nup);  /* remove upvalues */
+}
+
+
+
+/*
+** {======================================================
+** getn-setn: size for arrays
+** =======================================================
+*/
+
+static int checkint (lua_State *L, int topop) {
+  int n = (int)lua_tonumber(L, -1);
+  if (n == 0 && !lua_isnumber(L, -1)) n = -1;
+  lua_pop(L, topop);
+  return n;
+}
+
+
+static void getsizes (lua_State *L) {
+  lua_rawgeti(L, LUA_REGISTRYINDEX, ARRAYSIZE_REF);
+  if (lua_isnil(L, -1)) {  /* no `size' table? */
+    lua_pop(L, 1);  /* remove nil */
+    lua_newtable(L);  /* create it */
+    lua_pushvalue(L, -1);  /* `size' will be its own metatable */
+    lua_setmetatable(L, -2);
+    lua_pushliteral(L, "__mode");
+    lua_pushliteral(L, "k");
+    lua_rawset(L, -3);  /* metatable(N).__mode = "k" */
+    lua_pushvalue(L, -1);
+    lua_rawseti(L, LUA_REGISTRYINDEX, ARRAYSIZE_REF);  /* store in register */
+  }
+}
+
+
+void luaL_setn (lua_State *L, int t, int n) {
+  t = abs_index(L, t);
+  lua_pushliteral(L, "n");
+  lua_rawget(L, t);
+  if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */
+    lua_pushliteral(L, "n");  /* use it */
+    lua_pushnumber(L, (lua_Number)n);
+    lua_rawset(L, t);
+  }
+  else {  /* use `sizes' */
+    getsizes(L);
+    lua_pushvalue(L, t);
+    lua_pushnumber(L, (lua_Number)n);
+    lua_rawset(L, -3);  /* sizes[t] = n */
+    lua_pop(L, 1);  /* remove `sizes' */
+  }
+}
+
+
+int luaL_getn (lua_State *L, int t) {
+  int n;
+  t = abs_index(L, t);
+  lua_pushliteral(L, "n");  /* try t.n */
+  lua_rawget(L, t);
+  if ((n = checkint(L, 1)) >= 0) return n;
+  getsizes(L);  /* else try sizes[t] */
+  lua_pushvalue(L, t);
+  lua_rawget(L, -2);
+  if ((n = checkint(L, 2)) >= 0) return n;
+  for (n = 1; ; n++) {  /* else must count elements */
+    lua_rawgeti(L, t, n);
+    if (lua_isnil(L, -1)) break;
+    lua_pop(L, 1);
+  }
+  lua_pop(L, 1);
+  return n - 1;
+}
+
+/* }====================================================== */
+
+
+
 /*
 ** {======================================================
 ** Generic Buffer manipulation
@@ -122,7 +328,6 @@ LUALIB_API void luaL_verror (lua_State *L, const char *fmt, ...) {
 */
 
 
-#define buffempty(B)	((B)->p == (B)->buffer)
 #define bufflen(B)	((B)->p - (B)->buffer)
 #define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
 
@@ -135,29 +340,27 @@ static int emptybuffer (luaL_Buffer *B) {
   else {
     lua_pushlstring(B->L, B->buffer, l);
     B->p = B->buffer;
-    B->level++;
+    B->lvl++;
     return 1;
   }
 }
 
 
 static void adjuststack (luaL_Buffer *B) {
-  if (B->level > 1) {
+  if (B->lvl > 1) {
     lua_State *L = B->L;
     int toget = 1;  /* number of levels to concat */
     size_t toplen = lua_strlen(L, -1);
     do {
       size_t l = lua_strlen(L, -(toget+1));
-      if (B->level - toget + 1 >= LIMIT || toplen > l) {
+      if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
         toplen += l;
         toget++;
       }
       else break;
-    } while (toget < B->level);
-    if (toget >= 2) {
-      lua_concat(L, toget);
-      B->level = B->level - toget + 1;
-    }
+    } while (toget < B->lvl);
+    lua_concat(L, toget);
+    B->lvl = B->lvl - toget + 1;
   }
 }
 
@@ -182,11 +385,8 @@ LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
 
 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
   emptybuffer(B);
-  if (B->level == 0)
-    lua_pushlstring(B->L, NULL, 0);
-  else if (B->level > 1)
-    lua_concat(B->L, B->level);
-  B->level = 1;
+  lua_concat(B->L, B->lvl);
+  B->lvl = 1;
 }
 
 
@@ -201,7 +401,7 @@ LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
   else {
     if (emptybuffer(B))
       lua_insert(L, -2);  /* put buffer before new value */
-    B->level++;  /* add new value into B stack */
+    B->lvl++;  /* add new value into B stack */
     adjuststack(B);
   }
 }
@@ -210,7 +410,182 @@ LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
   B->L = L;
   B->p = B->buffer;
-  B->level = 0;
+  B->lvl = 0;
+}
+
+/* }====================================================== */
+
+
+LUALIB_API int luaL_ref (lua_State *L, int t) {
+  int ref;
+  t = abs_index(L, t);
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 1);  /* remove from stack */
+    return LUA_REFNIL;  /* `nil' has a unique fixed reference */
+  }
+  lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
+  ref = (int)lua_tonumber(L, -1);  /* ref = t[FREELIST_REF] */
+  lua_pop(L, 1);  /* remove it from stack */
+  if (ref != 0) {  /* any free element? */
+    lua_rawgeti(L, t, ref);  /* remove it from list */
+    lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
+  }
+  else {  /* no free elements */
+    ref = luaL_getn(L, t);
+    if (ref < RESERVED_REFS)
+      ref = RESERVED_REFS;  /* skip reserved references */
+    ref++;  /* create new reference */
+    luaL_setn(L, t, ref);
+  }
+  lua_rawseti(L, t, ref);
+  return ref;
+}
+
+
+LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
+  if (ref >= 0) {
+    t = abs_index(L, t);
+    lua_rawgeti(L, t, FREELIST_REF);
+    lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
+    lua_pushnumber(L, (lua_Number)ref);
+    lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
+  }
+}
+
+
+
+/*
+** {======================================================
+** Load functions
+** =======================================================
+*/
+
+typedef struct LoadF {
+  FILE *f;
+  char buff[LUAL_BUFFERSIZE];
+} LoadF;
+
+
+static const char *getF (lua_State *L, void *ud, size_t *size) {
+  LoadF *lf = (LoadF *)ud;
+  (void)L;
+  if (feof(lf->f)) return NULL;
+  *size = fread(lf->buff, 1, LUAL_BUFFERSIZE, lf->f);
+  return (*size > 0) ? lf->buff : NULL;
+}
+
+
+static int errfile (lua_State *L, int fnameindex) {
+  const char *filename = lua_tostring(L, fnameindex) + 1;
+  lua_pushfstring(L, "cannot read %s: %s", filename, strerror(errno));
+  lua_remove(L, fnameindex);
+  return LUA_ERRFILE;
+}
+
+
+LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
+  LoadF lf;
+  int status, readstatus;
+  int c;
+  int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
+  if (filename == NULL) {
+    lua_pushliteral(L, "=stdin");
+    lf.f = stdin;
+  }
+  else {
+    lua_pushfstring(L, "@%s", filename);
+    lf.f = fopen(filename, "r");
+  }
+  if (lf.f == NULL) return errfile(L, fnameindex);  /* unable to open file */
+  c = ungetc(getc(lf.f), lf.f);
+  if (!(isspace(c) || isprint(c)) && lf.f != stdin) {  /* binary file? */
+    fclose(lf.f);
+    lf.f = fopen(filename, "rb");  /* reopen in binary mode */
+    if (lf.f == NULL) return errfile(L, fnameindex); /* unable to reopen file */
+  }
+  status = lua_load(L, getF, &lf, lua_tostring(L, -1));
+  readstatus = ferror(lf.f);
+  if (lf.f != stdin) fclose(lf.f);  /* close file (even in case of errors) */
+  if (readstatus) {
+    lua_settop(L, fnameindex);  /* ignore results from `lua_load' */
+    return errfile(L, fnameindex);
+  }
+  lua_remove(L, fnameindex);
+  return status;
+}
+
+
+typedef struct LoadS {
+  const char *s;
+  size_t size;
+} LoadS;
+
+
+static const char *getS (lua_State *L, void *ud, size_t *size) {
+  LoadS *ls = (LoadS *)ud;
+  (void)L;
+  if (ls->size == 0) return NULL;
+  *size = ls->size;
+  ls->size = 0;
+  return ls->s;
+}
+
+
+LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
+                                const char *name) {
+  LoadS ls;
+  ls.s = buff;
+  ls.size = size;
+  return lua_load(L, getS, &ls, name);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** compatibility code
+** =======================================================
+*/
+
+
+static void callalert (lua_State *L, int status) {
+  if (status != 0) {
+    lua_getglobal(L, "_ALERT");
+    if (lua_isfunction(L, -1)) {
+      lua_insert(L, -2);
+      lua_call(L, 1, 0);
+    }
+    else {  /* no _ALERT function; print it on stderr */
+      fprintf(stderr, "%s\n", lua_tostring(L, -2));
+      lua_pop(L, 2);  /* remove error message and _ALERT */
+    }
+  }
+}
+
+
+static int aux_do (lua_State *L, int status) {
+  if (status == 0) {  /* parse OK? */
+    status = lua_pcall(L, 0, LUA_MULTRET, 0);  /* call main */
+  }
+  callalert(L, status);
+  return status;
+}
+
+
+LUALIB_API int lua_dofile (lua_State *L, const char *filename) {
+  return aux_do(L, luaL_loadfile(L, filename));
+}
+
+
+LUALIB_API int lua_dobuffer (lua_State *L, const char *buff, size_t size,
+                          const char *name) {
+  return aux_do(L, luaL_loadbuffer(L, buff, size, name));
+}
+
+
+LUALIB_API int lua_dostring (lua_State *L, const char *str) {
+  return lua_dobuffer(L, str, strlen(str), str);
 }
 
 /* }====================================================== */
diff --git a/src/lib/lbaselib.c b/src/lib/lbaselib.c
index 29bad6a8..7381cf33 100644
--- a/src/lib/lbaselib.c
+++ b/src/lib/lbaselib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.17a 2000/11/06 13:45:18 roberto Exp $
+** $Id: lbaselib.c,v 1.130 2003/04/03 13:35:34 roberto Exp $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -11,51 +11,15 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define lbaselib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
-#include "luadebug.h"
 #include "lualib.h"
 
 
 
-/*
-** If your system does not support `stderr', redefine this function, or
-** redefine _ERRORMESSAGE so that it won't need _ALERT.
-*/
-static int luaB__ALERT (lua_State *L) {
-  fputs(luaL_check_string(L, 1), stderr);
-  return 0;
-}
-
-
-/*
-** Basic implementation of _ERRORMESSAGE.
-** The library `liolib' redefines _ERRORMESSAGE for better error information.
-*/
-static int luaB__ERRORMESSAGE (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TSTRING);
-  lua_getglobal(L, LUA_ALERT);
-  if (lua_isfunction(L, -1)) {  /* avoid error loop if _ALERT is not defined */
-    lua_Debug ar;
-    lua_pushstring(L, "error: ");
-    lua_pushvalue(L, 1);
-    if (lua_getstack(L, 1, &ar)) {
-      lua_getinfo(L, "Sl", &ar);
-      if (ar.source && ar.currentline > 0) {
-        char buff[100];
-        sprintf(buff, "\n  <%.70s: line %d>", ar.short_src, ar.currentline);
-        lua_pushstring(L, buff);
-        lua_concat(L, 2);
-      }
-    }
-    lua_pushstring(L, "\n");
-    lua_concat(L, 3);
-    lua_rawcall(L, 1, 0);
-  }
-  return 0;
-}
-
 
 /*
 ** If your system does not support `stdout', you can just remove this function.
@@ -71,10 +35,10 @@ static int luaB_print (lua_State *L) {
     const char *s;
     lua_pushvalue(L, -1);  /* function to be called */
     lua_pushvalue(L, i);   /* value to print */
-    lua_rawcall(L, 1, 1);
+    lua_call(L, 1, 1);
     s = lua_tostring(L, -1);  /* get result */
     if (s == NULL)
-      lua_error(L, "`tostring' must return a string to `print'");
+      return luaL_error(L, "`tostring' must return a string to `print'");
     if (i>1) fputs("\t", stdout);
     fputs(s, stdout);
     lua_pop(L, 1);  /* pop result */
@@ -85,7 +49,7 @@ static int luaB_print (lua_State *L) {
 
 
 static int luaB_tonumber (lua_State *L) {
-  int base = luaL_opt_int(L, 2, 10);
+  int base = luaL_optint(L, 2, 10);
   if (base == 10) {  /* standard conversion */
     luaL_checkany(L, 1);
     if (lua_isnumber(L, 1)) {
@@ -94,15 +58,15 @@ static int luaB_tonumber (lua_State *L) {
     }
   }
   else {
-    const char *s1 = luaL_check_string(L, 1);
+    const char *s1 = luaL_checkstring(L, 1);
     char *s2;
     unsigned long n;
-    luaL_arg_check(L, 2 <= base && base <= 36, 2, "base out of range");
+    luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
     n = strtoul(s1, &s2, base);
     if (s1 != s2) {  /* at least one valid digit? */
-      while (isspace((unsigned char)*s2)) s2++;  /* skip trailing spaces */
+      while (isspace((unsigned char)(*s2))) s2++;  /* skip trailing spaces */
       if (*s2 == '\0') {  /* no invalid trailing characters? */
-        lua_pushnumber(L, n);
+        lua_pushnumber(L, (lua_Number)n);
         return 1;
       }
     }
@@ -113,55 +77,99 @@ static int luaB_tonumber (lua_State *L) {
 
 
 static int luaB_error (lua_State *L) {
-  lua_error(L, luaL_opt_string(L, 1, NULL));
-  return 0;  /* to avoid warnings */
+  int level = luaL_optint(L, 2, 1);
+  luaL_checkany(L, 1);
+  if (!lua_isstring(L, 1) || level == 0)
+    lua_pushvalue(L, 1);  /* propagate error message without changes */
+  else {  /* add extra information */
+    luaL_where(L, level);
+    lua_pushvalue(L, 1);
+    lua_concat(L, 2);
+  }
+  return lua_error(L);
 }
 
-static int luaB_setglobal (lua_State *L) {
-  luaL_checkany(L, 2);
-  lua_setglobal(L, luaL_check_string(L, 1));
-  return 0;
+
+static int luaB_getmetatable (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (!lua_getmetatable(L, 1)) {
+    lua_pushnil(L);
+    return 1;  /* no metatable */
+  }
+  luaL_getmetafield(L, 1, "__metatable");
+  return 1;  /* returns either __metatable field (if present) or metatable */
 }
 
-static int luaB_getglobal (lua_State *L) {
-  lua_getglobal(L, luaL_check_string(L, 1));
+
+static int luaB_setmetatable (lua_State *L) {
+  int t = lua_type(L, 2);
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
+                    "nil or table expected");
+  if (luaL_getmetafield(L, 1, "__metatable"))
+    luaL_error(L, "cannot change a protected metatable");
+  lua_settop(L, 2);
+  lua_setmetatable(L, 1);
   return 1;
 }
 
-static int luaB_tag (lua_State *L) {
-  luaL_checkany(L, 1);
-  lua_pushnumber(L, lua_tag(L, 1));
-  return 1;
+
+static void getfunc (lua_State *L) {
+  if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);
+  else {
+    lua_Debug ar;
+    int level = luaL_optint(L, 1, 1);
+    luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
+    if (lua_getstack(L, level, &ar) == 0)
+      luaL_argerror(L, 1, "invalid level");
+    lua_getinfo(L, "f", &ar);
+    if (lua_isnil(L, -1))
+      luaL_error(L, "no function environment for tail call at level %d",
+                    level);
+  }
 }
 
-static int luaB_settag (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TTABLE);
-  lua_pushvalue(L, 1);  /* push table */
-  lua_settag(L, luaL_check_int(L, 2));
-  return 1;  /* return table */
+
+static int aux_getfenv (lua_State *L) {
+  lua_getfenv(L, -1);
+  lua_pushliteral(L, "__fenv");
+  lua_rawget(L, -2);
+  return !lua_isnil(L, -1);
 }
 
-static int luaB_newtag (lua_State *L) {
-  lua_pushnumber(L, lua_newtag(L));
+
+static int luaB_getfenv (lua_State *L) {
+  getfunc(L);
+  if (!aux_getfenv(L))  /* __fenv not defined? */
+    lua_pop(L, 1);  /* remove it, to return real environment */
   return 1;
 }
 
-static int luaB_copytagmethods (lua_State *L) {
-  lua_pushnumber(L, lua_copytagmethods(L, luaL_check_int(L, 1),
-                                          luaL_check_int(L, 2)));
-  return 1;
+
+static int luaB_setfenv (lua_State *L) {
+  luaL_checktype(L, 2, LUA_TTABLE);
+  getfunc(L);
+  if (aux_getfenv(L))  /* __fenv defined? */
+    luaL_error(L, "`setfenv' cannot change a protected environment");
+  else
+    lua_pop(L, 2);  /* remove __fenv and real environment table */
+  lua_pushvalue(L, 2);
+  if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0)
+    lua_replace(L, LUA_GLOBALSINDEX);
+  else if (lua_setfenv(L, -2) == 0)
+    luaL_error(L, "`setfenv' cannot change environment of given function");
+  return 0;
 }
 
-static int luaB_globals (lua_State *L) {
-  lua_getglobals(L);  /* value to be returned */
-  if (!lua_isnull(L, 1)) {
-    luaL_checktype(L, 1, LUA_TTABLE);
-    lua_pushvalue(L, 1);  /* new table of globals */
-    lua_setglobals(L);
-  }
+
+static int luaB_rawequal (lua_State *L) {
+  luaL_checkany(L, 1);
+  luaL_checkany(L, 2);
+  lua_pushboolean(L, lua_rawequal(L, 1, 2));
   return 1;
 }
 
+
 static int luaB_rawget (lua_State *L) {
   luaL_checktype(L, 1, LUA_TTABLE);
   luaL_checkany(L, 2);
@@ -177,39 +185,16 @@ static int luaB_rawset (lua_State *L) {
   return 1;
 }
 
-static int luaB_settagmethod (lua_State *L) {
-  int tag = luaL_check_int(L, 1);
-  const char *event = luaL_check_string(L, 2);
-  luaL_arg_check(L, lua_isfunction(L, 3) || lua_isnil(L, 3), 3,
-                 "function or nil expected");
-  if (strcmp(event, "gc") == 0)
-    lua_error(L, "deprecated use: cannot set the `gc' tag method from Lua");
-  lua_gettagmethod(L, tag, event);
-  lua_pushvalue(L, 3);
-  lua_settagmethod(L, tag, event);
-  return 1;
-}
-
-
-static int luaB_gettagmethod (lua_State *L) {
-  int tag = luaL_check_int(L, 1);
-  const char *event = luaL_check_string(L, 2);
-  if (strcmp(event, "gc") == 0)
-    lua_error(L, "deprecated use: cannot get the `gc' tag method from Lua");
-  lua_gettagmethod(L, tag, event);
-  return 1;
-}
-
 
 static int luaB_gcinfo (lua_State *L) {
-  lua_pushnumber(L, lua_getgccount(L));
-  lua_pushnumber(L, lua_getgcthreshold(L));
+  lua_pushnumber(L, (lua_Number)lua_getgccount(L));
+  lua_pushnumber(L, (lua_Number)lua_getgcthreshold(L));
   return 2;
 }
 
 
 static int luaB_collectgarbage (lua_State *L) {
-  lua_setgcthreshold(L, luaL_opt_int(L, 1, 0));
+  lua_setgcthreshold(L, luaL_optint(L, 1, 0));
   return 0;
 }
 
@@ -233,83 +218,116 @@ static int luaB_next (lua_State *L) {
 }
 
 
-static int passresults (lua_State *L, int status, int oldtop) {
-  static const char *const errornames[] =
-    {"ok", "run-time error", "file error", "syntax error",
-     "memory error", "error in error handling"};
-  if (status == 0) {
-    int nresults = lua_gettop(L) - oldtop;
-    if (nresults > 0)
-      return nresults;  /* results are already on the stack */
-    else {
-      lua_pushuserdata(L, NULL);  /* at least one result to signal no errors */
-      return 1;
-    }
+static int luaB_pairs (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  lua_pushliteral(L, "next");
+  lua_rawget(L, LUA_GLOBALSINDEX);  /* return generator, */
+  lua_pushvalue(L, 1);  /* state, */
+  lua_pushnil(L);  /* and initial value */
+  return 3;
+}
+
+
+static int luaB_ipairs (lua_State *L) {
+  lua_Number i = lua_tonumber(L, 2);
+  luaL_checktype(L, 1, LUA_TTABLE);
+  if (i == 0 && lua_isnone(L, 2)) {  /* `for' start? */
+    lua_pushliteral(L, "ipairs");
+    lua_rawget(L, LUA_GLOBALSINDEX);  /* return generator, */
+    lua_pushvalue(L, 1);  /* state, */
+    lua_pushnumber(L, 0);  /* and initial value */
+    return 3;
+  }
+  else {  /* `for' step */
+    i++;  /* next value */
+    lua_pushnumber(L, i);
+    lua_rawgeti(L, 1, (int)i);
+    return (lua_isnil(L, -1)) ? 0 : 2;
   }
-  else {  /* error */
+}
+
+
+static int load_aux (lua_State *L, int status) {
+  if (status == 0)  /* OK? */
+    return 1;
+  else {
     lua_pushnil(L);
-    lua_pushstring(L, errornames[status]);  /* error code */
-    return 2;
+    lua_insert(L, -2);  /* put before error message */
+    return 2;  /* return nil plus error message */
   }
 }
 
-static int luaB_dostring (lua_State *L) {
-  int oldtop = lua_gettop(L);
+
+static int luaB_loadstring (lua_State *L) {
   size_t l;
-  const char *s = luaL_check_lstr(L, 1, &l);
-  if (*s == '\33')  /* binary files start with ESC... */
-    lua_error(L, "`dostring' cannot run pre-compiled code");
-  return passresults(L, lua_dobuffer(L, s, l, luaL_opt_string(L, 2, s)), oldtop);
+  const char *s = luaL_checklstring(L, 1, &l);
+  const char *chunkname = luaL_optstring(L, 2, s);
+  return load_aux(L, luaL_loadbuffer(L, s, l, chunkname));
+}
+
+
+static int luaB_loadfile (lua_State *L) {
+  const char *fname = luaL_optstring(L, 1, NULL);
+  return load_aux(L, luaL_loadfile(L, fname));
 }
 
 
 static int luaB_dofile (lua_State *L) {
-  int oldtop = lua_gettop(L);
-  const char *fname = luaL_opt_string(L, 1, NULL);
-  return passresults(L, lua_dofile(L, fname), oldtop);
+  const char *fname = luaL_optstring(L, 1, NULL);
+  int status = luaL_loadfile(L, fname);
+  if (status != 0) lua_error(L);
+  lua_call(L, 0, LUA_MULTRET);
+  return lua_gettop(L) - 1;
 }
 
 
-static int luaB_call (lua_State *L) {
-  int oldtop;
-  const char *options = luaL_opt_string(L, 3, "");
-  int err = 0;  /* index of old error method */
-  int i, status;
-  int n;
-  luaL_checktype(L, 2, LUA_TTABLE);
-  n = lua_getn(L, 2);
-  if (!lua_isnull(L, 4)) {  /* set new error method */
-    lua_getglobal(L, LUA_ERRORMESSAGE);
-    err = lua_gettop(L);  /* get index */
-    lua_pushvalue(L, 4);
-    lua_setglobal(L, LUA_ERRORMESSAGE);
-  }
-  oldtop = lua_gettop(L);  /* top before function-call preparation */
-  /* push function */
-  lua_pushvalue(L, 1);
-  luaL_checkstack(L, n, "too many arguments");
-  for (i=0; i<n; i++)  /* push arg[1...n] */
-    lua_rawgeti(L, 2, i+1);
-  status = lua_call(L, n, LUA_MULTRET);
-  if (err != 0) {  /* restore old error method */
-    lua_pushvalue(L, err);
-    lua_setglobal(L, LUA_ERRORMESSAGE);
-  }
-  if (status != 0) {  /* error in call? */
-    if (strchr(options, 'x'))
-      lua_pushnil(L);  /* return nil to signal the error */
-    else
-      lua_error(L, NULL);  /* propagate error without additional messages */
-    return 1;
-  }
-  if (strchr(options, 'p'))  /* pack results? */
-    lua_error(L, "deprecated option `p' in `call'");
-  return lua_gettop(L) - oldtop;  /* results are already on the stack */
+static int luaB_assert (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (!lua_toboolean(L, 1))
+    return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
+  lua_settop(L, 1);
+  return 1;
+}
+
+
+static int luaB_unpack (lua_State *L) {
+  int n, i;
+  luaL_checktype(L, 1, LUA_TTABLE);
+  n = luaL_getn(L, 1);
+  luaL_checkstack(L, n, "table too big to unpack");
+  for (i=1; i<=n; i++)  /* push arg[1...n] */
+    lua_rawgeti(L, 1, i);
+  return n;
+}
+
+
+static int luaB_pcall (lua_State *L) {
+  int status;
+  luaL_checkany(L, 1);
+  status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);
+  lua_pushboolean(L, (status == 0));
+  lua_insert(L, 1);
+  return lua_gettop(L);  /* return status + all results */
+}
+
+
+static int luaB_xpcall (lua_State *L) {
+  int status;
+  luaL_checkany(L, 2);
+  lua_settop(L, 2);
+  lua_insert(L, 1);  /* put error function under function to be called */
+  status = lua_pcall(L, 0, LUA_MULTRET, 1);
+  lua_pushboolean(L, (status == 0));
+  lua_replace(L, 1);
+  return lua_gettop(L);  /* return status + all results */
 }
 
 
 static int luaB_tostring (lua_State *L) {
   char buff[64];
+  luaL_checkany(L, 1);
+  if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */
+    return 1;  /* use its value */
   switch (lua_type(L, 1)) {
     case LUA_TNUMBER:
       lua_pushstring(L, lua_tostring(L, 1));
@@ -317,6 +335,9 @@ static int luaB_tostring (lua_State *L) {
     case LUA_TSTRING:
       lua_pushvalue(L, 1);
       return 1;
+    case LUA_TBOOLEAN:
+      lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));
+      return 1;
     case LUA_TTABLE:
       sprintf(buff, "table: %p", lua_topointer(L, 1));
       break;
@@ -324,328 +345,330 @@ static int luaB_tostring (lua_State *L) {
       sprintf(buff, "function: %p", lua_topointer(L, 1));
       break;
     case LUA_TUSERDATA:
-      sprintf(buff, "userdata(%d): %p", lua_tag(L, 1), lua_touserdata(L, 1));
+    case LUA_TLIGHTUSERDATA:
+      sprintf(buff, "userdata: %p", lua_touserdata(L, 1));
+      break;
+    case LUA_TTHREAD:
+      sprintf(buff, "thread: %p", (void *)lua_tothread(L, 1));
       break;
     case LUA_TNIL:
-      lua_pushstring(L, "nil");
+      lua_pushliteral(L, "nil");
       return 1;
-    default:
-      luaL_argerror(L, 1, "value expected");
   }
   lua_pushstring(L, buff);
   return 1;
 }
 
 
-static int luaB_foreachi (lua_State *L) {
-  int n, i;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  luaL_checktype(L, 2, LUA_TFUNCTION);
-  n = lua_getn(L, 1);
-  for (i=1; i<=n; i++) {
-    lua_pushvalue(L, 2);  /* function */
-    lua_pushnumber(L, i);  /* 1st argument */
-    lua_rawgeti(L, 1, i);  /* 2nd argument */
-    lua_rawcall(L, 2, 1);
-    if (!lua_isnil(L, -1))
-      return 1;
-    lua_pop(L, 1);  /* remove nil result */
+static int luaB_newproxy (lua_State *L) {
+  lua_settop(L, 1);
+  lua_newuserdata(L, 0);  /* create proxy */
+  if (lua_toboolean(L, 1) == 0)
+    return 1;  /* no metatable */
+  else if (lua_isboolean(L, 1)) {
+    lua_newtable(L);  /* create a new metatable `m' ... */
+    lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
+    lua_pushboolean(L, 1);
+    lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
   }
-  return 0;
-}
-
-
-static int luaB_foreach (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TTABLE);
-  luaL_checktype(L, 2, LUA_TFUNCTION);
-  lua_pushnil(L);  /* first index */
-  for (;;) {
-    if (lua_next(L, 1) == 0)
-      return 0;
-    lua_pushvalue(L, 2);  /* function */
-    lua_pushvalue(L, -3);  /* key */
-    lua_pushvalue(L, -3);  /* value */
-    lua_rawcall(L, 2, 1);
-    if (!lua_isnil(L, -1))
-      return 1;
-    lua_pop(L, 2);  /* remove value and result */
+  else {
+    int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
+    if (lua_getmetatable(L, 1)) {
+      lua_rawget(L, lua_upvalueindex(1));
+      validproxy = lua_toboolean(L, -1);
+      lua_pop(L, 1);  /* remove value */
+    }
+    luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
+    lua_getmetatable(L, 1);  /* metatable is valid; get it */
   }
-}
-
-
-static int luaB_assert (lua_State *L) {
-  luaL_checkany(L, 1);
-  if (lua_isnil(L, 1))
-    luaL_verror(L, "assertion failed!  %.90s", luaL_opt_string(L, 2, ""));
-  return 0;
-}
-
-
-static int luaB_getn (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TTABLE);
-  lua_pushnumber(L, lua_getn(L, 1));
+  lua_setmetatable(L, 2);
   return 1;
 }
 
 
-static int luaB_tinsert (lua_State *L) {
-  int v = lua_gettop(L);  /* last argument: to be inserted */
-  int n, pos;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  n = lua_getn(L, 1);
-  if (v == 2)  /* called with only 2 arguments */
-    pos = n+1;
-  else
-    pos = luaL_check_int(L, 2);  /* 2nd argument is the position */
-  lua_pushstring(L, "n");
-  lua_pushnumber(L, n+1);
-  lua_rawset(L, 1);  /* t.n = n+1 */
-  for (; n>=pos; n--) {
-    lua_rawgeti(L, 1, n);
-    lua_rawseti(L, 1, n+1);  /* t[n+1] = t[n] */
-  }
-  lua_pushvalue(L, v);
-  lua_rawseti(L, 1, pos);  /* t[pos] = v */
-  return 0;
-}
-
+/*
+** {======================================================
+** `require' function
+** =======================================================
+*/
 
-static int luaB_tremove (lua_State *L) {
-  int pos, n;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  n = lua_getn(L, 1);
-  pos = luaL_opt_int(L, 2, n);
-  if (n <= 0) return 0;  /* table is "empty" */
-  lua_rawgeti(L, 1, pos);  /* result = t[pos] */
-  for ( ;pos<n; pos++) {
-    lua_rawgeti(L, 1, pos+1);
-    lua_rawseti(L, 1, pos);  /* a[pos] = a[pos+1] */
-  }
-  lua_pushstring(L, "n");
-  lua_pushnumber(L, n-1);
-  lua_rawset(L, 1);  /* t.n = n-1 */
-  lua_pushnil(L);
-  lua_rawseti(L, 1, n);  /* t[n] = nil */
-  return 1;
-}
 
+/* name of global that holds table with loaded packages */
+#define REQTAB		"_LOADED"
 
+/* name of global that holds the search path for packages */
+#define LUA_PATH	"LUA_PATH"
 
+#ifndef LUA_PATH_SEP
+#define LUA_PATH_SEP	';'
+#endif
 
-/*
-** {======================================================
-** Quicksort
-** (based on `Algorithms in MODULA-3', Robert Sedgewick;
-**  Addison-Wesley, 1993.)
-*/
+#ifndef LUA_PATH_MARK
+#define LUA_PATH_MARK	'?'
+#endif
 
+#ifndef LUA_PATH_DEFAULT
+#define LUA_PATH_DEFAULT	"?;?.lua"
+#endif
 
-static void set2 (lua_State *L, int i, int j) {
-  lua_rawseti(L, 1, i);
-  lua_rawseti(L, 1, j);
-}
 
-static int sort_comp (lua_State *L, int a, int b) {
-  /* WARNING: the caller (auxsort) must ensure stack space */
-  if (!lua_isnil(L, 2)) {  /* function? */
-    int res;
-    lua_pushvalue(L, 2);
-    lua_pushvalue(L, a-1);  /* -1 to compensate function */
-    lua_pushvalue(L, b-2);  /* -2 to compensate function and `a' */
-    lua_rawcall(L, 2, 1);
-    res = !lua_isnil(L, -1);
-    lua_pop(L, 1);
-    return res;
+static const char *getpath (lua_State *L) {
+  const char *path;
+  lua_getglobal(L, LUA_PATH);  /* try global variable */
+  path = lua_tostring(L, -1);
+  lua_pop(L, 1);
+  if (path) return path;
+  path = getenv(LUA_PATH);  /* else try environment variable */
+  if (path) return path;
+  return LUA_PATH_DEFAULT;  /* else use default */
+}
+
+
+static const char *pushnextpath (lua_State *L, const char *path) {
+  const char *l;
+  if (*path == '\0') return NULL;  /* no more paths */
+  if (*path == LUA_PATH_SEP) path++;  /* skip separator */
+  l = strchr(path, LUA_PATH_SEP);  /* find next separator */
+  if (l == NULL) l = path+strlen(path);
+  lua_pushlstring(L, path, l - path);  /* directory name */
+  return l;
+}
+
+
+static void pushcomposename (lua_State *L) {
+  const char *path = lua_tostring(L, -1);
+  const char *wild;
+  int n = 1;
+  while ((wild = strchr(path, LUA_PATH_MARK)) != NULL) {
+    /* is there stack space for prefix, name, and eventual last sufix? */
+    luaL_checkstack(L, 3, "too many marks in a path component");
+    lua_pushlstring(L, path, wild - path);  /* push prefix */
+    lua_pushvalue(L, 1);  /* push package name (in place of MARK) */
+    path = wild + 1;  /* continue after MARK */
+    n += 2;
   }
-  else  /* a < b? */
-    return lua_lessthan(L, a, b);
-}
-
-static void auxsort (lua_State *L, int l, int u) {
-  while (l < u) {  /* for tail recursion */
-    int i, j;
-    /* sort elements a[l], a[(l+u)/2] and a[u] */
-    lua_rawgeti(L, 1, l);
-    lua_rawgeti(L, 1, u);
-    if (sort_comp(L, -1, -2))  /* a[u] < a[l]? */
-      set2(L, l, u);  /* swap a[l] - a[u] */
-    else
-      lua_pop(L, 2);
-    if (u-l == 1) break;  /* only 2 elements */
-    i = (l+u)/2;
-    lua_rawgeti(L, 1, i);
-    lua_rawgeti(L, 1, l);
-    if (sort_comp(L, -2, -1))  /* a[i]<a[l]? */
-      set2(L, i, l);
-    else {
-      lua_pop(L, 1);  /* remove a[l] */
-      lua_rawgeti(L, 1, u);
-      if (sort_comp(L, -1, -2))  /* a[u]<a[i]? */
-        set2(L, i, u);
-      else
-        lua_pop(L, 2);
+  lua_pushstring(L, path);  /* push last sufix (`n' already includes this) */
+  lua_concat(L, n);
+}
+
+
+static int luaB_require (lua_State *L) {
+  const char *path;
+  int status = LUA_ERRFILE;  /* not found (yet) */
+  luaL_checkstring(L, 1);
+  lua_settop(L, 1);
+  lua_getglobal(L, REQTAB);
+  if (!lua_istable(L, 2)) return luaL_error(L, "`" REQTAB "' is not a table");
+  path = getpath(L);
+  lua_pushvalue(L, 1);  /* check package's name in book-keeping table */
+  lua_rawget(L, 2);
+  if (lua_toboolean(L, -1))  /* is it there? */
+    return 1;  /* package is already loaded; return its result */
+  else {  /* must load it */
+    while (status == LUA_ERRFILE) {
+      lua_settop(L, 3);  /* reset stack position */
+      if ((path = pushnextpath(L, path)) == NULL) break;
+      pushcomposename(L);
+      status = luaL_loadfile(L, lua_tostring(L, -1));  /* try to load it */
     }
-    if (u-l == 2) break;  /* only 3 elements */
-    lua_rawgeti(L, 1, i);  /* Pivot */
-    lua_pushvalue(L, -1);
-    lua_rawgeti(L, 1, u-1);
-    set2(L, i, u-1);
-    /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
-    i = l; j = u-1;
-    for (;;) {  /* invariant: a[l..i] <= P <= a[j..u] */
-      /* repeat ++i until a[i] >= P */
-      while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
-        if (i>u) lua_error(L, "invalid order function for sorting");
-        lua_pop(L, 1);  /* remove a[i] */
-      }
-      /* repeat --j until a[j] <= P */
-      while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
-        if (j<l) lua_error(L, "invalid order function for sorting");
-        lua_pop(L, 1);  /* remove a[j] */
-      }
-      if (j<i) {
-        lua_pop(L, 3);  /* pop pivot, a[i], a[j] */
-        break;
+  }
+  switch (status) {
+    case 0: {
+      lua_getglobal(L, "_REQUIREDNAME");  /* save previous name */
+      lua_insert(L, -2);  /* put it below function */
+      lua_pushvalue(L, 1);
+      lua_setglobal(L, "_REQUIREDNAME");  /* set new name */
+      lua_call(L, 0, 1);  /* run loaded module */
+      lua_insert(L, -2);  /* put result below previous name */
+      lua_setglobal(L, "_REQUIREDNAME");  /* reset to previous name */
+      if (lua_isnil(L, -1)) {  /* no/nil return? */
+        lua_pushboolean(L, 1);
+        lua_replace(L, -2);  /* replace to true */
       }
-      set2(L, i, j);
+      lua_pushvalue(L, 1);
+      lua_pushvalue(L, -2);
+      lua_rawset(L, 2);  /* mark it as loaded */
+      return 1;  /* return value */
     }
-    lua_rawgeti(L, 1, u-1);
-    lua_rawgeti(L, 1, i);
-    set2(L, u-1, i);  /* swap pivot (a[u-1]) with a[i] */
-    /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
-    /* adjust so that smaller "half" is in [j..i] and larger one in [l..u] */
-    if (i-l < u-i) {
-      j=l; i=i-1; l=i+2;
+    case LUA_ERRFILE: {  /* file not found */
+      return luaL_error(L, "could not load package `%s' from path `%s'",
+                            lua_tostring(L, 1), getpath(L));
     }
-    else {
-      j=i+1; i=u; u=j-2;
+    default: {
+      return luaL_error(L, "error loading package `%s' (%s)",
+                           lua_tostring(L, 1), lua_tostring(L, -1));
     }
-    auxsort(L, j, i);  /* call recursively the smaller one */
-  }  /* repeat the routine for the larger one */
-}
-
-static int luaB_sort (lua_State *L) {
-  int n;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  n = lua_getn(L, 1);
-  if (!lua_isnull(L, 2))  /* is there a 2nd argument? */
-    luaL_checktype(L, 2, LUA_TFUNCTION);
-  lua_settop(L, 2);  /* make sure there is two arguments */
-  auxsort(L, 1, n);
-  return 0;
+  }
 }
 
 /* }====================================================== */
 
 
+static const luaL_reg base_funcs[] = {
+  {"error", luaB_error},
+  {"getmetatable", luaB_getmetatable},
+  {"setmetatable", luaB_setmetatable},
+  {"getfenv", luaB_getfenv},
+  {"setfenv", luaB_setfenv},
+  {"next", luaB_next},
+  {"ipairs", luaB_ipairs},
+  {"pairs", luaB_pairs},
+  {"print", luaB_print},
+  {"tonumber", luaB_tonumber},
+  {"tostring", luaB_tostring},
+  {"type", luaB_type},
+  {"assert", luaB_assert},
+  {"unpack", luaB_unpack},
+  {"rawequal", luaB_rawequal},
+  {"rawget", luaB_rawget},
+  {"rawset", luaB_rawset},
+  {"pcall", luaB_pcall},
+  {"xpcall", luaB_xpcall},
+  {"collectgarbage", luaB_collectgarbage},
+  {"gcinfo", luaB_gcinfo},
+  {"loadfile", luaB_loadfile},
+  {"dofile", luaB_dofile},
+  {"loadstring", luaB_loadstring},
+  {"require", luaB_require},
+  {NULL, NULL}
+};
+
 
 /*
 ** {======================================================
-** Deprecated functions to manipulate global environment.
+** Coroutine library
 ** =======================================================
 */
 
+static int auxresume (lua_State *L, lua_State *co, int narg) {
+  int status;
+  if (!lua_checkstack(co, narg))
+    luaL_error(L, "too many arguments to resume");
+  lua_xmove(L, co, narg);
+  status = lua_resume(co, narg);
+  if (status == 0) {
+    int nres = lua_gettop(co);
+    if (!lua_checkstack(L, nres))
+      luaL_error(L, "too many results to resume");
+    lua_xmove(co, L, nres);  /* move yielded values */
+    return nres;
+  }
+  else {
+    lua_xmove(co, L, 1);  /* move error message */
+    return -1;  /* error flag */
+  }
+}
 
-#define num_deprecated	4
-
-static const struct luaL_reg deprecated_names [num_deprecated] = {
-  {"foreachvar", luaB_foreach},
-  {"nextvar", luaB_next},
-  {"rawgetglobal", luaB_rawget},
-  {"rawsetglobal", luaB_rawset}
-};
 
+static int luaB_coresume (lua_State *L) {
+  lua_State *co = lua_tothread(L, 1);
+  int r;
+  luaL_argcheck(L, co, 1, "coroutine expected");
+  r = auxresume(L, co, lua_gettop(L) - 1);
+  if (r < 0) {
+    lua_pushboolean(L, 0);
+    lua_insert(L, -2);
+    return 2;  /* return false + error message */
+  }
+  else {
+    lua_pushboolean(L, 1);
+    lua_insert(L, -(r + 1));
+    return r + 1;  /* return true + `resume' returns */
+  }
+}
 
-#ifdef LUA_DEPRECATEDFUNCS
 
-/*
-** call corresponding function inserting `globals' as first argument
-*/
-static int deprecated_func (lua_State *L) {
-  lua_insert(L, 1);  /* upvalue is the function to be called */
-  lua_getglobals(L);
-  lua_insert(L, 2);  /* table of globals is 1o argument */
-  lua_rawcall(L, lua_gettop(L)-1, LUA_MULTRET);
-  return lua_gettop(L);  /* return all results */
+static int luaB_auxwrap (lua_State *L) {
+  lua_State *co = lua_tothread(L, lua_upvalueindex(1));
+  int r = auxresume(L, co, lua_gettop(L));
+  if (r < 0) {
+    if (lua_isstring(L, -1)) {  /* error object is a string? */
+      luaL_where(L, 1);  /* add extra info */
+      lua_insert(L, -2);
+      lua_concat(L, 2);
+    }
+    lua_error(L);  /* propagate error */
+  }
+  return r;
 }
 
 
-static void deprecated_funcs (lua_State *L) {
-  int i;
-  for (i=0; i<num_deprecated; i++) {
-    lua_pushcfunction(L, deprecated_names[i].func);
-    lua_pushcclosure(L, deprecated_func, 1);
-    lua_setglobal(L, deprecated_names[i].name);
-  }
+static int luaB_cocreate (lua_State *L) {
+  lua_State *NL = lua_newthread(L);
+  luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1), 1,
+    "Lua function expected");
+  lua_pushvalue(L, 1);  /* move function to top */
+  lua_xmove(L, NL, 1);  /* move function from L to NL */
+  return 1;
 }
 
 
-#else
+static int luaB_cowrap (lua_State *L) {
+  luaB_cocreate(L);
+  lua_pushcclosure(L, luaB_auxwrap, 1);
+  return 1;
+}
 
-/*
-** gives an explicit error in any attempt to call a deprecated function
-*/
-static int deprecated_func (lua_State *L) {
-  luaL_verror(L, "function `%.20s' is deprecated", lua_tostring(L, -1));
-  return 0;  /* to avoid warnings */
+
+static int luaB_yield (lua_State *L) {
+  return lua_yield(L, lua_gettop(L));
 }
 
 
-static void deprecated_funcs (lua_State *L) {
-  int i;
-  for (i=0; i<num_deprecated; i++) {
-    lua_pushstring(L, deprecated_names[i].name);
-    lua_pushcclosure(L, deprecated_func, 1);
-    lua_setglobal(L, deprecated_names[i].name);
+static int luaB_costatus (lua_State *L) {
+  lua_State *co = lua_tothread(L, 1);
+  luaL_argcheck(L, co, 1, "coroutine expected");
+  if (L == co) lua_pushliteral(L, "running");
+  else {
+    lua_Debug ar;
+    if (lua_getstack(co, 0, &ar) == 0 && lua_gettop(co) == 0)
+      lua_pushliteral(L, "dead");
+    else
+      lua_pushliteral(L, "suspended");
   }
+  return 1;
 }
 
-#endif
-
-/* }====================================================== */
 
-static const struct luaL_reg base_funcs[] = {
-  {LUA_ALERT, luaB__ALERT},
-  {LUA_ERRORMESSAGE, luaB__ERRORMESSAGE},
-  {"call", luaB_call},
-  {"collectgarbage", luaB_collectgarbage},
-  {"copytagmethods", luaB_copytagmethods},
-  {"dofile", luaB_dofile},
-  {"dostring", luaB_dostring},
-  {"error", luaB_error},
-  {"foreach", luaB_foreach},
-  {"foreachi", luaB_foreachi},
-  {"gcinfo", luaB_gcinfo},
-  {"getglobal", luaB_getglobal},
-  {"gettagmethod", luaB_gettagmethod},
-  {"globals", luaB_globals},
-  {"newtag", luaB_newtag},
-  {"next", luaB_next},
-  {"print", luaB_print},
-  {"rawget", luaB_rawget},
-  {"rawset", luaB_rawset},
-  {"rawgettable", luaB_rawget},  /* for compatibility */
-  {"rawsettable", luaB_rawset},  /* for compatibility */
-  {"setglobal", luaB_setglobal},
-  {"settag", luaB_settag},
-  {"settagmethod", luaB_settagmethod},
-  {"tag", luaB_tag},
-  {"tonumber", luaB_tonumber},
-  {"tostring", luaB_tostring},
-  {"type", luaB_type},
-  {"assert", luaB_assert},
-  {"getn", luaB_getn},
-  {"sort", luaB_sort},
-  {"tinsert", luaB_tinsert},
-  {"tremove", luaB_tremove}
+static const luaL_reg co_funcs[] = {
+  {"create", luaB_cocreate},
+  {"wrap", luaB_cowrap},
+  {"resume", luaB_coresume},
+  {"yield", luaB_yield},
+  {"status", luaB_costatus},
+  {NULL, NULL}
 };
 
+/* }====================================================== */
+
 
 
-LUALIB_API void lua_baselibopen (lua_State *L) {
-  luaL_openl(L, base_funcs);
-  lua_pushstring(L, LUA_VERSION);
-  lua_setglobal(L, "_VERSION");
-  deprecated_funcs(L);
+static void base_open (lua_State *L) {
+  lua_pushliteral(L, "_G");
+  lua_pushvalue(L, LUA_GLOBALSINDEX);
+  luaL_openlib(L, NULL, base_funcs, 0);  /* open lib into global table */
+  lua_pushliteral(L, "_VERSION");
+  lua_pushliteral(L, LUA_VERSION);
+  lua_rawset(L, -3);  /* set global _VERSION */
+  /* `newproxy' needs a weaktable as upvalue */
+  lua_pushliteral(L, "newproxy");
+  lua_newtable(L);  /* new table `w' */
+  lua_pushvalue(L, -1);  /* `w' will be its own metatable */
+  lua_setmetatable(L, -2);
+  lua_pushliteral(L, "__mode");
+  lua_pushliteral(L, "k");
+  lua_rawset(L, -3);  /* metatable(w).__mode = "k" */
+  lua_pushcclosure(L, luaB_newproxy, 1);
+  lua_rawset(L, -3);  /* set global `newproxy' */
+  lua_rawset(L, -1);  /* set global _G */
+}
+
+
+LUALIB_API int luaopen_base (lua_State *L) {
+  base_open(L);
+  luaL_openlib(L, LUA_COLIBNAME, co_funcs, 0);
+  lua_newtable(L);
+  lua_setglobal(L, REQTAB);
+  return 0;
 }
 
diff --git a/src/lib/ldblib.c b/src/lib/ldblib.c
index 636dbe05..6dc9b64c 100644
--- a/src/lib/ldblib.c
+++ b/src/lib/ldblib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.29 2000/11/06 17:58:38 roberto Exp $
+** $Id: ldblib.c,v 1.80 2003/04/03 13:35:34 roberto Exp $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -9,10 +9,11 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define ldblib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
-#include "luadebug.h"
 #include "lualib.h"
 
 
@@ -20,43 +21,41 @@
 static void settabss (lua_State *L, const char *i, const char *v) {
   lua_pushstring(L, i);
   lua_pushstring(L, v);
-  lua_settable(L, -3);
+  lua_rawset(L, -3);
 }
 
 
 static void settabsi (lua_State *L, const char *i, int v) {
   lua_pushstring(L, i);
-  lua_pushnumber(L, v);
-  lua_settable(L, -3);
+  lua_pushnumber(L, (lua_Number)v);
+  lua_rawset(L, -3);
 }
 
 
 static int getinfo (lua_State *L) {
   lua_Debug ar;
-  const char *options = luaL_opt_string(L, 2, "flnSu");
-  char buff[20];
+  const char *options = luaL_optstring(L, 2, "flnSu");
   if (lua_isnumber(L, 1)) {
-    if (!lua_getstack(L, (int)lua_tonumber(L, 1), &ar)) {
+    if (!lua_getstack(L, (int)(lua_tonumber(L, 1)), &ar)) {
       lua_pushnil(L);  /* level out of range */
       return 1;
     }
   }
   else if (lua_isfunction(L, 1)) {
+    lua_pushfstring(L, ">%s", options);
+    options = lua_tostring(L, -1);
     lua_pushvalue(L, 1);
-    sprintf(buff, ">%.10s", options);
-    options = buff;
   }
   else
-    luaL_argerror(L, 1, "function or level expected");
+    return luaL_argerror(L, 1, "function or level expected");
   if (!lua_getinfo(L, options, &ar))
-    luaL_argerror(L, 2, "invalid option");
+    return luaL_argerror(L, 2, "invalid option");
   lua_newtable(L);
   for (; *options; options++) {
     switch (*options) {
       case 'S':
         settabss(L, "source", ar.source);
-        if (ar.source)
-          settabss(L, "short_src", ar.short_src);
+        settabss(L, "short_src", ar.short_src);
         settabsi(L, "linedefined", ar.linedefined);
         settabss(L, "what", ar.what);
         break;
@@ -71,9 +70,9 @@ static int getinfo (lua_State *L) {
         settabss(L, "namewhat", ar.namewhat);
         break;
       case 'f':
-        lua_pushstring(L, "func");
+        lua_pushliteral(L, "func");
         lua_pushvalue(L, -3);
-        lua_settable(L, -3);
+        lua_rawset(L, -3);
         break;
     }
   }
@@ -84,9 +83,9 @@ static int getinfo (lua_State *L) {
 static int getlocal (lua_State *L) {
   lua_Debug ar;
   const char *name;
-  if (!lua_getstack(L, luaL_check_int(L, 1), &ar))  /* level out of range? */
-    luaL_argerror(L, 1, "level out of range");
-  name = lua_getlocal(L, &ar, luaL_check_int(L, 2));
+  if (!lua_getstack(L, luaL_checkint(L, 1), &ar))  /* level out of range? */
+    return luaL_argerror(L, 1, "level out of range");
+  name = lua_getlocal(L, &ar, luaL_checkint(L, 2));
   if (name) {
     lua_pushstring(L, name);
     lua_pushvalue(L, -2);
@@ -101,88 +100,200 @@ static int getlocal (lua_State *L) {
 
 static int setlocal (lua_State *L) {
   lua_Debug ar;
-  if (!lua_getstack(L, luaL_check_int(L, 1), &ar))  /* level out of range? */
-    luaL_argerror(L, 1, "level out of range");
+  if (!lua_getstack(L, luaL_checkint(L, 1), &ar))  /* level out of range? */
+    return luaL_argerror(L, 1, "level out of range");
   luaL_checkany(L, 3);
-  lua_pushstring(L, lua_setlocal(L, &ar, luaL_check_int(L, 2)));
+  lua_pushstring(L, lua_setlocal(L, &ar, luaL_checkint(L, 2)));
   return 1;
 }
 
 
+static int auxupvalue (lua_State *L, int get) {
+  const char *name;
+  int n = luaL_checkint(L, 2);
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  if (lua_iscfunction(L, 1)) return 0;  /* cannot touch C upvalues from Lua */
+  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
+  if (name == NULL) return 0;
+  lua_pushstring(L, name);
+  lua_insert(L, -(get+1));
+  return get + 1;
+}
+
+
+static int getupvalue (lua_State *L) {
+  return auxupvalue(L, 1);
+}
+
+
+static int setupvalue (lua_State *L) {
+  luaL_checkany(L, 3);
+  return auxupvalue(L, 0);
+}
+
+
 
-/* dummy variables (to define unique addresses) */
-static char key1, key2;
-#define KEY_CALLHOOK	(&key1)
-#define KEY_LINEHOOK	(&key2)
+static const char KEY_HOOK = 'h';
 
 
-static void hookf (lua_State *L, void *key) {
-  lua_getregistry(L);
-  lua_pushuserdata(L, key);
-  lua_gettable(L, -2);
+static void hookf (lua_State *L, lua_Debug *ar) {
+  static const char *const hooknames[] =
+    {"call", "return", "line", "count", "tail return"};
+  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
+  lua_rawget(L, LUA_REGISTRYINDEX);
   if (lua_isfunction(L, -1)) {
-    lua_pushvalue(L, 1);
-    lua_rawcall(L, 1, 0);
+    lua_pushstring(L, hooknames[(int)ar->event]);
+    if (ar->currentline >= 0)
+      lua_pushnumber(L, (lua_Number)ar->currentline);
+    else lua_pushnil(L);
+    lua_assert(lua_getinfo(L, "lS", ar));
+    lua_call(L, 2, 0);
   }
   else
     lua_pop(L, 1);  /* pop result from gettable */
-  lua_pop(L, 1);  /* pop table */
 }
 
 
-static void callf (lua_State *L, lua_Debug *ar) {
-  lua_pushstring(L, ar->event);
-  hookf(L, KEY_CALLHOOK);
+static int makemask (const char *smask, int count) {
+  int mask = 0;
+  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
+  if (strchr(smask, 'r')) mask |= LUA_MASKRET;
+  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
+  if (count > 0) mask |= LUA_MASKCOUNT;
+  return mask;
 }
 
 
-static void linef (lua_State *L, lua_Debug *ar) {
-  lua_pushnumber(L, ar->currentline);
-  hookf(L, KEY_LINEHOOK);
+static char *unmakemask (int mask, char *smask) {
+  int i = 0;
+  if (mask & LUA_MASKCALL) smask[i++] = 'c';
+  if (mask & LUA_MASKRET) smask[i++] = 'r';
+  if (mask & LUA_MASKLINE) smask[i++] = 'l';
+  smask[i] = '\0';
+  return smask;
 }
 
 
-static void sethook (lua_State *L, void *key, lua_Hook hook,
-                     lua_Hook (*sethookf)(lua_State * L, lua_Hook h)) {
-  lua_settop(L, 1);
-  if (lua_isnil(L, 1))
-    (*sethookf)(L, NULL);
-  else if (lua_isfunction(L, 1))
-    (*sethookf)(L, hook);
-  else
-    luaL_argerror(L, 1, "function expected");
-  lua_getregistry(L);
-  lua_pushuserdata(L, key);
-  lua_pushvalue(L, -1);  /* dup key */
-  lua_gettable(L, -3);   /* get old value */
-  lua_pushvalue(L, -2);  /* key (again) */
+static int sethook (lua_State *L) {
+  if (lua_isnoneornil(L, 1)) {
+    lua_settop(L, 1);
+    lua_sethook(L, NULL, 0, 0);  /* turn off hooks */
+  }
+  else {
+    const char *smask = luaL_checkstring(L, 2);
+    int count = luaL_optint(L, 3, 0);
+    luaL_checktype(L, 1, LUA_TFUNCTION);
+    lua_sethook(L, hookf, makemask(smask, count), count);
+  }
+  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
   lua_pushvalue(L, 1);
-  lua_settable(L, -5);  /* set new value */
+  lua_rawset(L, LUA_REGISTRYINDEX);  /* set new hook */
+  return 0;
 }
 
 
-static int setcallhook (lua_State *L) {
-  sethook(L, KEY_CALLHOOK, callf, lua_setcallhook);
-  return 1;
+static int gethook (lua_State *L) {
+  char buff[5];
+  int mask = lua_gethookmask(L);
+  lua_Hook hook = lua_gethook(L);
+  if (hook != NULL && hook != hookf)  /* external hook? */
+    lua_pushliteral(L, "external hook");
+  else {
+    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
+    lua_rawget(L, LUA_REGISTRYINDEX);   /* get hook */
+  }
+  lua_pushstring(L, unmakemask(mask, buff));
+  lua_pushnumber(L, (lua_Number)lua_gethookcount(L));
+  return 3;
+}
+
+
+static int debug (lua_State *L) {
+  for (;;) {
+    char buffer[250];
+    fputs("lua_debug> ", stderr);
+    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
+        strcmp(buffer, "cont\n") == 0)
+      return 0;
+    lua_dostring(L, buffer);
+    lua_settop(L, 0);  /* remove eventual returns */
+  }
 }
 
 
-static int setlinehook (lua_State *L) {
-  sethook(L, KEY_LINEHOOK, linef, lua_setlinehook);
+#define LEVELS1	12	/* size of the first part of the stack */
+#define LEVELS2	10	/* size of the second part of the stack */
+
+static int errorfb (lua_State *L) {
+  int level = 1;  /* skip level 0 (it's this function) */
+  int firstpart = 1;  /* still before eventual `...' */
+  lua_Debug ar;
+  if (lua_gettop(L) == 0)
+    lua_pushliteral(L, "");
+  else if (!lua_isstring(L, 1)) return 1;  /* no string message */
+  else lua_pushliteral(L, "\n");
+  lua_pushliteral(L, "stack traceback:");
+  while (lua_getstack(L, level++, &ar)) {
+    if (level > LEVELS1 && firstpart) {
+      /* no more than `LEVELS2' more levels? */
+      if (!lua_getstack(L, level+LEVELS2, &ar))
+        level--;  /* keep going */
+      else {
+        lua_pushliteral(L, "\n\t...");  /* too many levels */
+        while (lua_getstack(L, level+LEVELS2, &ar))  /* find last levels */
+          level++;
+      }
+      firstpart = 0;
+      continue;
+    }
+    lua_pushliteral(L, "\n\t");
+    lua_getinfo(L, "Snl", &ar);
+    lua_pushfstring(L, "%s:", ar.short_src);
+    if (ar.currentline > 0)
+      lua_pushfstring(L, "%d:", ar.currentline);
+    switch (*ar.namewhat) {
+      case 'g':  /* global */ 
+      case 'l':  /* local */
+      case 'f':  /* field */
+      case 'm':  /* method */
+        lua_pushfstring(L, " in function `%s'", ar.name);
+        break;
+      default: {
+        if (*ar.what == 'm')  /* main? */
+          lua_pushfstring(L, " in main chunk");
+        else if (*ar.what == 'C' || *ar.what == 't')
+          lua_pushliteral(L, " ?");  /* C function or tail call */
+        else
+          lua_pushfstring(L, " in function <%s:%d>",
+                             ar.short_src, ar.linedefined);
+      }
+    }
+    lua_concat(L, lua_gettop(L));
+  }
+  lua_concat(L, lua_gettop(L));
   return 1;
 }
 
 
-static const struct luaL_reg dblib[] = {
+static const luaL_reg dblib[] = {
   {"getlocal", getlocal},
   {"getinfo", getinfo},
-  {"setcallhook", setcallhook},
-  {"setlinehook", setlinehook},
-  {"setlocal", setlocal}
+  {"gethook", gethook},
+  {"getupvalue", getupvalue},
+  {"sethook", sethook},
+  {"setlocal", setlocal},
+  {"setupvalue", setupvalue},
+  {"debug", debug},
+  {"traceback", errorfb},
+  {NULL, NULL}
 };
 
 
-LUALIB_API void lua_dblibopen (lua_State *L) {
-  luaL_openl(L, dblib);
+LUALIB_API int luaopen_debug (lua_State *L) {
+  luaL_openlib(L, LUA_DBLIBNAME, dblib, 0);
+  lua_pushliteral(L, "_TRACEBACK");
+  lua_pushcfunction(L, errorfb);
+  lua_settable(L, LUA_GLOBALSINDEX);
+  return 1;
 }
 
diff --git a/src/lib/liolib.c b/src/lib/liolib.c
index 70f8057a..14bd7d99 100644
--- a/src/lib/liolib.c
+++ b/src/lib/liolib.c
@@ -1,302 +1,309 @@
 /*
-** $Id: liolib.c,v 1.91 2000/10/31 13:10:24 roberto Exp $
+** $Id: liolib.c,v 2.39 2003/03/19 21:16:12 roberto Exp $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
 
 
-#include <ctype.h>
+#include <errno.h>
+#include <locale.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 
+#define liolib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
-#include "luadebug.h"
 #include "lualib.h"
 
 
-#ifndef OLD_ANSI
-#include <errno.h>
-#include <locale.h>
-#define realloc(b,s)    ((b) == NULL ? malloc(s) : (realloc)(b, s))
-#define free(b)         if (b) (free)(b)
+
+/*
+** by default, gcc does not get `tmpname'
+*/
+#ifndef USE_TMPNAME
+#ifdef __GNUC__
+#define USE_TMPNAME	0
 #else
-/* no support for locale and for strerror: fake them */
-#define setlocale(a,b)	((void)a, strcmp((b),"C")==0?"C":NULL)
-#define LC_ALL		0
-#define LC_COLLATE	0
-#define LC_CTYPE	0
-#define LC_MONETARY	0
-#define LC_NUMERIC	0
-#define LC_TIME		0
-#define strerror(e)	"generic I/O error"
-#define errno		(-1)
+#define USE_TMPNAME	1
+#endif
 #endif
 
 
+/*
+** by default, posix systems get `popen'
+*/
+#ifndef USE_POPEN
+#ifdef _POSIX_C_SOURCE
+#if _POSIX_C_SOURCE >= 2
+#define USE_POPEN	1
+#endif
+#endif
+#endif
 
-#ifdef POPEN
-/* FILE *popen();
-int pclose(); */
-#define CLOSEFILE(L, f)    ((pclose(f) == -1) ? fclose(f) : 0)
-#else
-/* no support for popen */
-#define popen(x,y) NULL  /* that is, popen always fails */
-#define CLOSEFILE(L, f)    (fclose(f))
+#ifndef USE_POPEN
+#define USE_POPEN	0
 #endif
 
 
-#define INFILE	0
-#define OUTFILE 1
 
-typedef struct IOCtrl {
-  int ref[2];  /* ref for strings _INPUT/_OUTPUT */
-  int iotag;    /* tag for file handles */
-  int closedtag;  /* tag for closed handles */
-} IOCtrl;
+
+/*
+** {======================================================
+** FILE Operations
+** =======================================================
+*/
+
+
+#if !USE_POPEN
+#define pclose(f)    (-1)
+#endif
 
 
+#define FILEHANDLE		"FILE*"
 
-static const char *const filenames[] = {"_INPUT", "_OUTPUT"};
+#define IO_INPUT		"_input"
+#define IO_OUTPUT		"_output"
 
 
-static int pushresult (lua_State *L, int i) {
+static int pushresult (lua_State *L, int i, const char *filename) {
   if (i) {
-    lua_pushuserdata(L, NULL);
+    lua_pushboolean(L, 1);
     return 1;
   }
   else {
     lua_pushnil(L);
-    lua_pushstring(L, strerror(errno));
+    if (filename)
+      lua_pushfstring(L, "%s: %s", filename, strerror(errno));
+    else
+      lua_pushfstring(L, "%s", strerror(errno));
     lua_pushnumber(L, errno);
-    return 3;;
-  }
-}
-
-
-/*
-** {======================================================
-** FILE Operations
-** =======================================================
-*/
-
-
-static FILE *gethandle (lua_State *L, IOCtrl *ctrl, int f) {
-  void *p = lua_touserdata(L, f);
-  if (p != NULL) {  /* is `f' a userdata ? */
-    int ftag = lua_tag(L, f);
-    if (ftag == ctrl->iotag)  /* does it have the correct tag? */
-      return (FILE *)p;
-    else if (ftag == ctrl->closedtag)
-      lua_error(L, "cannot access a closed file");
-    /* else go through */
+    return 3;
   }
-  return NULL;
 }
 
 
-static FILE *getnonullfile (lua_State *L, IOCtrl *ctrl, int arg) {
-  FILE *f = gethandle(L, ctrl, arg);
-  luaL_arg_check(L, f, arg, "invalid file handle");
+static FILE **topfile (lua_State *L, int findex) {
+  FILE **f = (FILE **)luaL_checkudata(L, findex, FILEHANDLE);
+  if (f == NULL) luaL_argerror(L, findex, "bad file");
   return f;
 }
 
 
-static FILE *getfilebyref (lua_State *L, IOCtrl *ctrl, int inout) {
-  FILE *f;
-  lua_getglobals(L);
-  lua_getref(L, ctrl->ref[inout]);
-  lua_rawget(L, -2);
-  f = gethandle(L, ctrl, -1);
-  if (f == NULL)
-    luaL_verror(L, "global variable `%.10s' is not a file handle",
-                filenames[inout]);
-  return f;
+static int io_type (lua_State *L) {
+  FILE **f = (FILE **)luaL_checkudata(L, 1, FILEHANDLE);
+  if (f == NULL) lua_pushnil(L);
+  else if (*f == NULL)
+    lua_pushliteral(L, "closed file");
+  else
+    lua_pushliteral(L, "file");
+  return 1;
 }
 
 
-static void setfilebyname (lua_State *L, IOCtrl *ctrl, FILE *f,
-                           const char *name) {
-  lua_pushusertag(L, f, ctrl->iotag);
-  lua_setglobal(L, name);
+static FILE *tofile (lua_State *L, int findex) {
+  FILE **f = topfile(L, findex);
+  if (*f == NULL)
+    luaL_error(L, "attempt to use a closed file");
+  return *f;
 }
 
 
-#define setfile(L,ctrl,f,inout)	(setfilebyname(L,ctrl,f,filenames[inout]))
 
+/*
+** When creating file handles, always creates a `closed' file handle
+** before opening the actual file; so, if there is a memory error, the
+** file is not left opened.
+*/
+static FILE **newfile (lua_State *L) {
+  FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
+  *pf = NULL;  /* file handle is currently `closed' */
+  luaL_getmetatable(L, FILEHANDLE);
+  lua_setmetatable(L, -2);
+  return pf;
+}
 
-static int setreturn (lua_State *L, IOCtrl *ctrl, FILE *f, int inout) {
-  if (f == NULL)
-    return pushresult(L, 0);
-  else {
-    setfile(L, ctrl, f, inout);
-    lua_pushusertag(L, f, ctrl->iotag);
-    return 1;
+
+/*
+** assumes that top of the stack is the `io' library, and next is
+** the `io' metatable
+*/
+static void registerfile (lua_State *L, FILE *f, const char *name,
+                                                 const char *impname) {
+  lua_pushstring(L, name);
+  *newfile(L) = f;
+  if (impname) {
+    lua_pushstring(L, impname);
+    lua_pushvalue(L, -2);
+    lua_settable(L, -6);  /* metatable[impname] = file */
   }
+  lua_settable(L, -3);  /* io[name] = file */
 }
 
 
-static int closefile (lua_State *L, IOCtrl *ctrl, FILE *f) {
+static int aux_close (lua_State *L) {
+  FILE *f = tofile(L, 1);
   if (f == stdin || f == stdout || f == stderr)
-    return 1;
+    return 0;  /* file cannot be closed */
   else {
-    lua_pushusertag(L, f, ctrl->iotag);
-    lua_settag(L, ctrl->closedtag);
-    return (CLOSEFILE(L, f) == 0);
+    int ok = (pclose(f) != -1) || (fclose(f) == 0);
+    if (ok)
+      *(FILE **)lua_touserdata(L, 1) = NULL;  /* mark file as closed */
+    return ok;
   }
 }
 
 
 static int io_close (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  lua_pop(L, 1);  /* remove upvalue */
-  return pushresult(L, closefile(L, ctrl, getnonullfile(L, ctrl, 1)));
+  if (lua_isnone(L, 1)) {
+    lua_pushstring(L, IO_OUTPUT);
+    lua_rawget(L, lua_upvalueindex(1));
+  }
+  return pushresult(L, aux_close(L), NULL);
 }
 
 
-static int file_collect (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *f = getnonullfile(L, ctrl, 1);
-  if (f != stdin && f != stdout && f != stderr)
-    CLOSEFILE(L, f);
+static int io_gc (lua_State *L) {
+  FILE **f = topfile(L, 1);
+  if (*f != NULL)  /* ignore closed files */
+    aux_close(L);
   return 0;
 }
 
 
-static int io_open (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *f;
-  lua_pop(L, 1);  /* remove upvalue */
-  f = fopen(luaL_check_string(L, 1), luaL_check_string(L, 2));
-  if (f) {
-    lua_pushusertag(L, f, ctrl->iotag);
-    return 1;
-  }
+static int io_tostring (lua_State *L) {
+  char buff[32];
+  FILE **f = topfile(L, 1);
+  if (*f == NULL)
+    strcpy(buff, "closed");
   else
-    return pushresult(L, 0);
+    sprintf(buff, "%p", lua_touserdata(L, 1));
+  lua_pushfstring(L, "file (%s)", buff);
+  return 1;
 }
 
 
+static int io_open (lua_State *L) {
+  const char *filename = luaL_checkstring(L, 1);
+  const char *mode = luaL_optstring(L, 2, "r");
+  FILE **pf = newfile(L);
+  *pf = fopen(filename, mode);
+  return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
+}
 
-static int io_fromto (lua_State *L, int inout, const char *mode) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *current;
-  lua_pop(L, 1);  /* remove upvalue */
-  if (lua_isnull(L, 1)) {
-    closefile(L, ctrl, getfilebyref(L, ctrl, inout));
-    current = (inout == 0) ? stdin : stdout;    
-  }
-  else if (lua_tag(L, 1) == ctrl->iotag)  /* deprecated option */
-    current = (FILE *)lua_touserdata(L, 1);
-  else {
-    const char *s = luaL_check_string(L, 1);
-    current = (*s == '|') ? popen(s+1, mode) : fopen(s, mode);
-  }
-  return setreturn(L, ctrl, current, inout);
+
+static int io_popen (lua_State *L) {
+#if !USE_POPEN
+  luaL_error(L, "`popen' not supported");
+  return 0;
+#else
+  const char *filename = luaL_checkstring(L, 1);
+  const char *mode = luaL_optstring(L, 2, "r");
+  FILE **pf = newfile(L);
+  *pf = popen(filename, mode);
+  return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
+#endif
 }
 
 
-static int io_readfrom (lua_State *L) {
-  return io_fromto(L, INFILE, "r");
+static int io_tmpfile (lua_State *L) {
+  FILE **pf = newfile(L);
+  *pf = tmpfile();
+  return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
 }
 
 
-static int io_writeto (lua_State *L) {
-  return io_fromto(L, OUTFILE, "w");
+static FILE *getiofile (lua_State *L, const char *name) {
+  lua_pushstring(L, name);
+  lua_rawget(L, lua_upvalueindex(1));
+  return tofile(L, -1);
 }
 
 
-static int io_appendto (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *current;
-  lua_pop(L, 1);  /* remove upvalue */
-  current = fopen(luaL_check_string(L, 1), "a");
-  return setreturn(L, ctrl, current, OUTFILE);
+static int g_iofile (lua_State *L, const char *name, const char *mode) {
+  if (!lua_isnoneornil(L, 1)) {
+    const char *filename = lua_tostring(L, 1);
+    lua_pushstring(L, name);
+    if (filename) {
+      FILE **pf = newfile(L);
+      *pf = fopen(filename, mode);
+      if (*pf == NULL) {
+        lua_pushfstring(L, "%s: %s", filename, strerror(errno));
+        luaL_argerror(L, 1, lua_tostring(L, -1));
+      }
+    }
+    else {
+      tofile(L, 1);  /* check that it's a valid file handle */
+      lua_pushvalue(L, 1);
+    }
+    lua_rawset(L, lua_upvalueindex(1));
+  }
+  /* return current value */
+  lua_pushstring(L, name);
+  lua_rawget(L, lua_upvalueindex(1));
+  return 1;
 }
 
 
+static int io_input (lua_State *L) {
+  return g_iofile(L, IO_INPUT, "r");
+}
 
-/*
-** {======================================================
-** READ
-** =======================================================
-*/
 
+static int io_output (lua_State *L) {
+  return g_iofile(L, IO_OUTPUT, "w");
+}
 
 
-#ifdef LUA_COMPAT_READPATTERN
+static int io_readline (lua_State *L);
 
-/*
-** We cannot lookahead without need, because this can lock stdin.
-** This flag signals when we need to read a next char.
-*/
-#define NEED_OTHER (EOF-1)  /* just some flag different from EOF */
 
+static void aux_lines (lua_State *L, int idx, int close) {
+  lua_pushliteral(L, FILEHANDLE);
+  lua_rawget(L, LUA_REGISTRYINDEX);
+  lua_pushvalue(L, idx);
+  lua_pushboolean(L, close);  /* close/not close file when finished */
+  lua_pushcclosure(L, io_readline, 3);
+}
 
-static int read_pattern (lua_State *L, FILE *f, const char *p) {
-  int inskip = 0;  /* {skip} level */
-  int c = NEED_OTHER;
-  luaL_Buffer b;
-  luaL_buffinit(L, &b);
-  while (*p != '\0') {
-    switch (*p) {
-      case '{':
-        inskip++;
-        p++;
-        continue;
-      case '}':
-        if (!inskip) lua_error(L, "unbalanced braces in read pattern");
-        inskip--;
-        p++;
-        continue;
-      default: {
-        const char *ep = luaI_classend(L, p);  /* get what is next */
-        int m;  /* match result */
-        if (c == NEED_OTHER) c = getc(f);
-        m = (c==EOF) ? 0 : luaI_singlematch(c, p, ep);
-        if (m) {
-          if (!inskip) luaL_putchar(&b, c);
-          c = NEED_OTHER;
-        }
-        switch (*ep) {
-          case '+':  /* repetition (1 or more) */
-            if (!m) goto break_while;  /* pattern fails? */
-            /* else go through */
-          case '*':  /* repetition (0 or more) */
-            while (m) {  /* reads the same item until it fails */
-              c = getc(f);
-              m = (c==EOF) ? 0 : luaI_singlematch(c, p, ep);
-              if (m && !inskip) luaL_putchar(&b, c);
-            }
-            /* go through to continue reading the pattern */
-          case '?':  /* optional */
-            p = ep+1;  /* continues reading the pattern */
-            continue;
-          default:
-            if (!m) goto break_while;  /* pattern fails? */
-            p = ep;  /* else continues reading the pattern */
-        }
-      }
-    }
-  } break_while:
-  if (c != NEED_OTHER) ungetc(c, f);
-  luaL_pushresult(&b);  /* close buffer */
-  return (*p == '\0');
+
+static int f_lines (lua_State *L) {
+  tofile(L, 1);  /* check that it's a valid file handle */
+  aux_lines(L, 1, 0);
+  return 1;
 }
 
-#else
 
-#define read_pattern(L, f, p) (lua_error(L, "read patterns are deprecated"), 0)
+static int io_lines (lua_State *L) {
+  if (lua_isnoneornil(L, 1)) {  /* no arguments? */
+    lua_pushstring(L, IO_INPUT);
+    lua_rawget(L, lua_upvalueindex(1));  /* will iterate over default input */
+    return f_lines(L);
+  }
+  else {
+    const char *filename = luaL_checkstring(L, 1);
+    FILE **pf = newfile(L);
+    *pf = fopen(filename, "r");
+    luaL_argcheck(L, *pf, 1,  strerror(errno));
+    aux_lines(L, lua_gettop(L), 1);
+    return 1;
+  }
+}
+
 
-#endif
+/*
+** {======================================================
+** READ
+** =======================================================
+*/
 
 
 static int read_number (lua_State *L, FILE *f) {
-  double d;
-  if (fscanf(f, "%lf", &d) == 1) {
+  lua_Number d;
+  if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
     lua_pushnumber(L, d);
     return 1;
   }
@@ -304,175 +311,167 @@ static int read_number (lua_State *L, FILE *f) {
 }
 
 
-static int read_word (lua_State *L, FILE *f) {
-  int c;
-  luaL_Buffer b;
-  luaL_buffinit(L, &b);
-  do { c = fgetc(f); } while (isspace(c));  /* skip spaces */
-  while (c != EOF && !isspace(c)) {
-    luaL_putchar(&b, c);
-    c = fgetc(f);
-  }
+static int test_eof (lua_State *L, FILE *f) {
+  int c = getc(f);
   ungetc(c, f);
-  luaL_pushresult(&b);  /* close buffer */
-  return (lua_strlen(L, -1) > 0);
+  lua_pushlstring(L, NULL, 0);
+  return (c != EOF);
 }
 
 
 static int read_line (lua_State *L, FILE *f) {
-  int n = 0;
   luaL_Buffer b;
   luaL_buffinit(L, &b);
   for (;;) {
+    size_t l;
     char *p = luaL_prepbuffer(&b);
-    if (!fgets(p, LUAL_BUFFERSIZE, f))  /* read fails? */
-      break;
-    n = strlen(p);
-    if (p[n-1] != '\n')
-      luaL_addsize(&b, n); 
-    else {
-      luaL_addsize(&b, n-1);  /* do not add the `\n' */
-      break;
+    if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
+      luaL_pushresult(&b);  /* close buffer */
+      return (lua_strlen(L, -1) > 0);  /* check whether read something */
     }
-  }
-  luaL_pushresult(&b);  /* close buffer */
-  return (n > 0);  /* read something? */
-}
-
-
-static void read_file (lua_State *L, FILE *f) {
-  size_t len = 0;
-  size_t size = BUFSIZ;
-  char *buffer = NULL;
-  for (;;) {
-    char *newbuffer = (char *)realloc(buffer, size);
-    if (newbuffer == NULL) {
-      free(buffer);
-      lua_error(L, "not enough memory to read a file");
+    l = strlen(p);
+    if (p[l-1] != '\n')
+      luaL_addsize(&b, l);
+    else {
+      luaL_addsize(&b, l - 1);  /* do not include `eol' */
+      luaL_pushresult(&b);  /* close buffer */
+      return 1;  /* read at least an `eol' */
     }
-    buffer = newbuffer;
-    len += fread(buffer+len, sizeof(char), size-len, f);
-    if (len < size) break;  /* did not read all it could */
-    size *= 2;
   }
-  lua_pushlstring(L, buffer, len);
-  free(buffer);
 }
 
 
 static int read_chars (lua_State *L, FILE *f, size_t n) {
-  char *buffer;
-  size_t n1;
-  char statbuff[BUFSIZ];
-  if (n <= BUFSIZ)
-    buffer = statbuff;
-  else {
-    buffer = (char  *)malloc(n);
-    if (buffer == NULL)
-      lua_error(L, "not enough memory to read a file");
-  }
-  n1 = fread(buffer, sizeof(char), n, f);
-  lua_pushlstring(L, buffer, n1);
-  if (buffer != statbuff) free(buffer);
-  return (n1 > 0 || n == 0);
+  size_t rlen;  /* how much to read */
+  size_t nr;  /* number of chars actually read */
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
+  do {
+    char *p = luaL_prepbuffer(&b);
+    if (rlen > n) rlen = n;  /* cannot read more than asked */
+    nr = fread(p, sizeof(char), rlen, f);
+    luaL_addsize(&b, nr);
+    n -= nr;  /* still have to read `n' chars */
+  } while (n > 0 && nr == rlen);  /* until end of count or eof */
+  luaL_pushresult(&b);  /* close buffer */
+  return (n == 0 || lua_strlen(L, -1) > 0);
 }
 
 
-static int io_read (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  int lastarg = lua_gettop(L) - 1;
-  int firstarg = 1;
-  FILE *f = gethandle(L, ctrl, firstarg);
+static int g_read (lua_State *L, FILE *f, int first) {
+  int nargs = lua_gettop(L) - 1;
+  int success;
   int n;
-  if (f) firstarg++;
-  else f = getfilebyref(L, ctrl, INFILE);  /* get _INPUT */
-  lua_pop(L, 1);
-  if (firstarg > lastarg) {  /* no arguments? */
-    lua_settop(L, 0);  /* erase upvalue and other eventual garbage */
-    firstarg = lastarg = 1;  /* correct indices */
-    lua_pushstring(L, "*l");  /* push default argument */
+  if (nargs == 0) {  /* no arguments? */
+    success = read_line(L, f);
+    n = first+1;  /* to return 1 result */
   }
-  else  /* ensure stack space for all results and for auxlib's buffer */
-    luaL_checkstack(L, lastarg-firstarg+1+LUA_MINSTACK, "too many arguments");
-  for (n = firstarg; n<=lastarg; n++) {
-    int success;
-    if (lua_isnumber(L, n))
-      success = read_chars(L, f, (size_t)lua_tonumber(L, n));
-    else {
-      const char *p = luaL_check_string(L, n);
-      if (p[0] != '*')
-        success = read_pattern(L, f, p);  /* deprecated! */
+  else {  /* ensure stack space for all results and for auxlib's buffer */
+    luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
+    success = 1;
+    for (n = first; nargs-- && success; n++) {
+      if (lua_type(L, n) == LUA_TNUMBER) {
+        size_t l = (size_t)lua_tonumber(L, n);
+        success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
+      }
       else {
+        const char *p = lua_tostring(L, n);
+        luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
         switch (p[1]) {
           case 'n':  /* number */
-            if (!read_number(L, f)) goto endloop;  /* read fails */
-            continue;  /* number is already pushed; avoid the "pushstring" */
+            success = read_number(L, f);
+            break;
           case 'l':  /* line */
             success = read_line(L, f);
             break;
           case 'a':  /* file */
-            read_file(L, f);
+            read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
             success = 1; /* always success */
             break;
           case 'w':  /* word */
-            success = read_word(L, f);
-            break;
+            return luaL_error(L, "obsolete option `*w' to `read'");
           default:
-            luaL_argerror(L, n, "invalid format");
-            success = 0;  /* to avoid warnings */
+            return luaL_argerror(L, n, "invalid format");
         }
       }
     }
-    if (!success) {
-      lua_pop(L, 1);  /* remove last result */
-      break;  /* read fails */
+  }
+  if (!success) {
+    lua_pop(L, 1);  /* remove last result */
+    lua_pushnil(L);  /* push nil instead */
+  }
+  return n - first;
+}
+
+
+static int io_read (lua_State *L) {
+  return g_read(L, getiofile(L, IO_INPUT), 1);
+}
+
+
+static int f_read (lua_State *L) {
+  return g_read(L, tofile(L, 1), 2);
+}
+
+
+static int io_readline (lua_State *L) {
+  FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(2));
+  if (f == NULL)  /* file is already closed? */
+    luaL_error(L, "file is already closed");
+  if (read_line(L, f)) return 1;
+  else {  /* EOF */
+    if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
+      lua_settop(L, 0);
+      lua_pushvalue(L, lua_upvalueindex(2));
+      aux_close(L);  /* close it */
     }
-  } endloop:
-  return n - firstarg;
+    return 0;
+  }
 }
 
 /* }====================================================== */
 
 
-static int io_write (lua_State *L) {
-  int lastarg = lua_gettop(L) - 1;
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  int arg = 1;
+static int g_write (lua_State *L, FILE *f, int arg) {
+  int nargs = lua_gettop(L) - 1;
   int status = 1;
-  FILE *f = gethandle(L, ctrl, arg);
-  if (f) arg++;
-  else f = getfilebyref(L, ctrl, OUTFILE);  /* get _OUTPUT */
-  for (; arg <=  lastarg; arg++) {
-    if (lua_type(L, arg) == LUA_TNUMBER) {  /* LUA_NUMBER */
+  for (; nargs--; arg++) {
+    if (lua_type(L, arg) == LUA_TNUMBER) {
       /* optimization: could be done exactly as for strings */
-      status = status && fprintf(f, "%.16g", lua_tonumber(L, arg)) > 0;
+      status = status &&
+          fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
     }
     else {
       size_t l;
-      const char *s = luaL_check_lstr(L, arg, &l);
+      const char *s = luaL_checklstring(L, arg, &l);
       status = status && (fwrite(s, sizeof(char), l, f) == l);
     }
   }
-  pushresult(L, status);
-  return 1;
+  return pushresult(L, status, NULL);
+}
+
+
+static int io_write (lua_State *L) {
+  return g_write(L, getiofile(L, IO_OUTPUT), 1);
 }
 
 
-static int io_seek (lua_State *L) {
+static int f_write (lua_State *L) {
+  return g_write(L, tofile(L, 1), 2);
+}
+
+
+static int f_seek (lua_State *L) {
   static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
   static const char *const modenames[] = {"set", "cur", "end", NULL};
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *f;
-  int op;
-  long offset;
-  lua_pop(L, 1);  /* remove upvalue */
-  f = getnonullfile(L, ctrl, 1);
-  op = luaL_findstring(luaL_opt_string(L, 2, "cur"), modenames);
-  offset = luaL_opt_long(L, 3, 0);
-  luaL_arg_check(L, op != -1, 2, "invalid mode");
+  FILE *f = tofile(L, 1);
+  int op = luaL_findstring(luaL_optstring(L, 2, "cur"), modenames);
+  long offset = luaL_optlong(L, 3, 0);
+  luaL_argcheck(L, op != -1, 2, "invalid mode");
   op = fseek(f, offset, mode[op]);
   if (op)
-    return pushresult(L, 0);  /* error */
+    return pushresult(L, 0, NULL);  /* error */
   else {
     lua_pushnumber(L, ftell(f));
     return 1;
@@ -481,12 +480,51 @@ static int io_seek (lua_State *L) {
 
 
 static int io_flush (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_touserdata(L, -1);
-  FILE *f;
-  lua_pop(L, 1);  /* remove upvalue */
-  f = gethandle(L, ctrl, 1);
-  luaL_arg_check(L, f || lua_isnull(L, 1), 1, "invalid file handle");
-  return pushresult(L, fflush(f) == 0);
+  return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
+}
+
+
+static int f_flush (lua_State *L) {
+  return pushresult(L, fflush(tofile(L, 1)) == 0, NULL);
+}
+
+
+static const luaL_reg iolib[] = {
+  {"input", io_input},
+  {"output", io_output},
+  {"lines", io_lines},
+  {"close", io_close},
+  {"flush", io_flush},
+  {"open", io_open},
+  {"popen", io_popen},
+  {"read", io_read},
+  {"tmpfile", io_tmpfile},
+  {"type", io_type},
+  {"write", io_write},
+  {NULL, NULL}
+};
+
+
+static const luaL_reg flib[] = {
+  {"flush", f_flush},
+  {"read", f_read},
+  {"lines", f_lines},
+  {"seek", f_seek},
+  {"write", f_write},
+  {"close", io_close},
+  {"__gc", io_gc},
+  {"__tostring", io_tostring},
+  {NULL, NULL}
+};
+
+
+static void createmeta (lua_State *L) {
+  luaL_newmetatable(L, FILEHANDLE);  /* create new metatable for file handles */
+  /* file methods */
+  lua_pushliteral(L, "__index");
+  lua_pushvalue(L, -2);  /* push metatable */
+  lua_rawset(L, -3);  /* metatable.__index = metatable */
+  luaL_openlib(L, NULL, flib, 0);
 }
 
 /* }====================================================== */
@@ -499,220 +537,214 @@ static int io_flush (lua_State *L) {
 */
 
 static int io_execute (lua_State *L) {
-  lua_pushnumber(L, system(luaL_check_string(L, 1)));
+  lua_pushnumber(L, system(luaL_checkstring(L, 1)));
   return 1;
 }
 
 
 static int io_remove (lua_State *L) {
-  return pushresult(L, remove(luaL_check_string(L, 1)) == 0);
+  const char *filename = luaL_checkstring(L, 1);
+  return pushresult(L, remove(filename) == 0, filename);
 }
 
 
 static int io_rename (lua_State *L) {
-  return pushresult(L, rename(luaL_check_string(L, 1),
-                    luaL_check_string(L, 2)) == 0);
+  const char *fromname = luaL_checkstring(L, 1);
+  const char *toname = luaL_checkstring(L, 2);
+  return pushresult(L, rename(fromname, toname) == 0, fromname);
 }
 
 
 static int io_tmpname (lua_State *L) {
-  lua_pushstring(L, tmpnam(NULL));
+#if !USE_TMPNAME
+  luaL_error(L, "`tmpname' not supported");
+  return 0;
+#else
+  char buff[L_tmpnam];
+  if (tmpnam(buff) != buff)
+    return luaL_error(L, "unable to generate a unique filename in `tmpname'");
+  lua_pushstring(L, buff);
   return 1;
+#endif
 }
 
 
-
 static int io_getenv (lua_State *L) {
-  lua_pushstring(L, getenv(luaL_check_string(L, 1)));  /* if NULL push nil */
+  lua_pushstring(L, getenv(luaL_checkstring(L, 1)));  /* if NULL push nil */
   return 1;
 }
 
 
 static int io_clock (lua_State *L) {
-  lua_pushnumber(L, ((double)clock())/CLOCKS_PER_SEC);
+  lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC);
   return 1;
 }
 
 
+/*
+** {======================================================
+** Time/Date operations
+** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S,
+**   wday=%w+1, yday=%j, isdst=? }
+** =======================================================
+*/
+
+static void setfield (lua_State *L, const char *key, int value) {
+  lua_pushstring(L, key);
+  lua_pushnumber(L, value);
+  lua_rawset(L, -3);
+}
+
+static void setboolfield (lua_State *L, const char *key, int value) {
+  lua_pushstring(L, key);
+  lua_pushboolean(L, value);
+  lua_rawset(L, -3);
+}
+
+static int getboolfield (lua_State *L, const char *key) {
+  int res;
+  lua_pushstring(L, key);
+  lua_gettable(L, -2);
+  res = lua_toboolean(L, -1);
+  lua_pop(L, 1);
+  return res;
+}
+
+
+static int getfield (lua_State *L, const char *key, int d) {
+  int res;
+  lua_pushstring(L, key);
+  lua_gettable(L, -2);
+  if (lua_isnumber(L, -1))
+    res = (int)(lua_tonumber(L, -1));
+  else {
+    if (d == -2)
+      return luaL_error(L, "field `%s' missing in date table", key);
+    res = d;
+  }
+  lua_pop(L, 1);
+  return res;
+}
+
+
 static int io_date (lua_State *L) {
-  char b[256];
-  const char *s = luaL_opt_string(L, 1, "%c");
+  const char *s = luaL_optstring(L, 1, "%c");
+  time_t t = (time_t)(luaL_optnumber(L, 2, -1));
   struct tm *stm;
-  time_t t;
-  time(&t); stm = localtime(&t);
-  if (strftime(b, sizeof(b), s, stm))
-    lua_pushstring(L, b);
+  if (t == (time_t)(-1))  /* no time given? */
+    t = time(NULL);  /* use current time */
+  if (*s == '!') {  /* UTC? */
+    stm = gmtime(&t);
+    s++;  /* skip `!' */
+  }
   else
-    lua_error(L, "invalid `date' format");
+    stm = localtime(&t);
+  if (stm == NULL)  /* invalid date? */
+    lua_pushnil(L);
+  else if (strcmp(s, "*t") == 0) {
+    lua_newtable(L);
+    setfield(L, "sec", stm->tm_sec);
+    setfield(L, "min", stm->tm_min);
+    setfield(L, "hour", stm->tm_hour);
+    setfield(L, "day", stm->tm_mday);
+    setfield(L, "month", stm->tm_mon+1);
+    setfield(L, "year", stm->tm_year+1900);
+    setfield(L, "wday", stm->tm_wday+1);
+    setfield(L, "yday", stm->tm_yday+1);
+    setboolfield(L, "isdst", stm->tm_isdst);
+  }
+  else {
+    char b[256];
+    if (strftime(b, sizeof(b), s, stm))
+      lua_pushstring(L, b);
+    else
+      return luaL_error(L, "`date' format too long");
+  }
   return 1;
 }
 
 
-static int setloc (lua_State *L) {
-  static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,
-                      LC_NUMERIC, LC_TIME};
-  static const char *const catnames[] = {"all", "collate", "ctype", "monetary",
-     "numeric", "time", NULL};
-  int op = luaL_findstring(luaL_opt_string(L, 2, "all"), catnames);
-  luaL_arg_check(L, op != -1, 2, "invalid option");
-  lua_pushstring(L, setlocale(cat[op], luaL_check_string(L, 1)));
+static int io_time (lua_State *L) {
+  if (lua_isnoneornil(L, 1))  /* called without args? */
+    lua_pushnumber(L, time(NULL));  /* return current time */
+  else {
+    time_t t;
+    struct tm ts;
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_settop(L, 1);  /* make sure table is at the top */
+    ts.tm_sec = getfield(L, "sec", 0);
+    ts.tm_min = getfield(L, "min", 0);
+    ts.tm_hour = getfield(L, "hour", 12);
+    ts.tm_mday = getfield(L, "day", -2);
+    ts.tm_mon = getfield(L, "month", -2) - 1;
+    ts.tm_year = getfield(L, "year", -2) - 1900;
+    ts.tm_isdst = getboolfield(L, "isdst");
+    t = mktime(&ts);
+    if (t == (time_t)(-1))
+      lua_pushnil(L);
+    else
+      lua_pushnumber(L, t);
+  }
   return 1;
 }
 
 
-static int io_exit (lua_State *L) {
-  exit(luaL_opt_int(L, 1, EXIT_SUCCESS));
-  return 0;  /* to avoid warnings */
+static int io_difftime (lua_State *L) {
+  lua_pushnumber(L, difftime((time_t)(luaL_checknumber(L, 1)),
+                             (time_t)(luaL_optnumber(L, 2, 0))));
+  return 1;
 }
 
 /* }====================================================== */
 
 
-
-static int io_debug (lua_State *L) {
-  for (;;) {
-    char buffer[250];
-    fprintf(stderr, "lua_debug> ");
-    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
-        strcmp(buffer, "cont\n") == 0)
-      return 0;
-    lua_dostring(L, buffer);
-    lua_settop(L, 0);  /* remove eventual returns */
-  }
+static int io_setloc (lua_State *L) {
+  static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,
+                      LC_NUMERIC, LC_TIME};
+  static const char *const catnames[] = {"all", "collate", "ctype", "monetary",
+     "numeric", "time", NULL};
+  const char *l = lua_tostring(L, 1);
+  int op = luaL_findstring(luaL_optstring(L, 2, "all"), catnames);
+  luaL_argcheck(L, l || lua_isnoneornil(L, 1), 1, "string expected");
+  luaL_argcheck(L, op != -1, 2, "invalid option");
+  lua_pushstring(L, setlocale(cat[op], l));
+  return 1;
 }
 
 
-#define LEVELS1	12	/* size of the first part of the stack */
-#define LEVELS2	10	/* size of the second part of the stack */
-
-static int errorfb (lua_State *L) {
-  int level = 1;  /* skip level 0 (it's this function) */
-  int firstpart = 1;  /* still before eventual `...' */
-  lua_Debug ar;
-  luaL_Buffer b;
-  luaL_buffinit(L, &b);
-  luaL_addstring(&b, "error: ");
-  luaL_addstring(&b, luaL_check_string(L, 1));
-  luaL_addstring(&b, "\n");
-  while (lua_getstack(L, level++, &ar)) {
-    char buff[120];  /* enough to fit following `sprintf's */
-    if (level == 2)
-      luaL_addstring(&b, "stack traceback:\n");
-    else if (level > LEVELS1 && firstpart) {
-      /* no more than `LEVELS2' more levels? */
-      if (!lua_getstack(L, level+LEVELS2, &ar))
-        level--;  /* keep going */
-      else {
-        luaL_addstring(&b, "       ...\n");  /* too many levels */
-        while (lua_getstack(L, level+LEVELS2, &ar))  /* find last levels */
-          level++;
-      }
-      firstpart = 0;
-      continue;
-    }
-    sprintf(buff, "%4d:  ", level-1);
-    luaL_addstring(&b, buff);
-    lua_getinfo(L, "Snl", &ar);
-    switch (*ar.namewhat) {
-      case 'g':  case 'l':  /* global, local */
-        sprintf(buff, "function `%.50s'", ar.name);
-        break;
-      case 'f':  /* field */
-        sprintf(buff, "method `%.50s'", ar.name);
-        break;
-      case 't':  /* tag method */
-        sprintf(buff, "`%.50s' tag method", ar.name);
-        break;
-      default: {
-        if (*ar.what == 'm')  /* main? */
-          sprintf(buff, "main of %.70s", ar.short_src);
-        else if (*ar.what == 'C')  /* C function? */
-          sprintf(buff, "%.70s", ar.short_src);
-        else
-          sprintf(buff, "function <%d:%.70s>", ar.linedefined, ar.short_src);
-        ar.source = NULL;  /* do not print source again */
-      }
-    }
-    luaL_addstring(&b, buff);
-    if (ar.currentline > 0) {
-      sprintf(buff, " at line %d", ar.currentline);
-      luaL_addstring(&b, buff);
-    }
-    if (ar.source) {
-      sprintf(buff, " [%.70s]", ar.short_src);
-      luaL_addstring(&b, buff);
-    }
-    luaL_addstring(&b, "\n");
-  }
-  luaL_pushresult(&b);
-  lua_getglobal(L, LUA_ALERT);
-  if (lua_isfunction(L, -1)) {  /* avoid loop if _ALERT is not defined */
-    lua_pushvalue(L, -2);  /* error message */
-    lua_rawcall(L, 1, 0);
-  }
-  return 0;
+static int io_exit (lua_State *L) {
+  exit(luaL_optint(L, 1, EXIT_SUCCESS));
+  return 0;  /* to avoid warnings */
 }
 
-
-
-static const struct luaL_reg iolib[] = {
-  {LUA_ERRORMESSAGE, errorfb},
+static const luaL_reg syslib[] = {
   {"clock",     io_clock},
-  {"date",     io_date},
-  {"debug",    io_debug},
-  {"execute",  io_execute},
-  {"exit",     io_exit},
-  {"getenv",   io_getenv},
-  {"remove",   io_remove},
-  {"rename",   io_rename},
-  {"setlocale", setloc},
-  {"tmpname",   io_tmpname}
+  {"date",      io_date},
+  {"difftime",  io_difftime},
+  {"execute",   io_execute},
+  {"exit",      io_exit},
+  {"getenv",    io_getenv},
+  {"remove",    io_remove},
+  {"rename",    io_rename},
+  {"setlocale", io_setloc},
+  {"time",      io_time},
+  {"tmpname",   io_tmpname},
+  {NULL, NULL}
 };
 
+/* }====================================================== */
 
-static const struct luaL_reg iolibtag[] = {
-  {"appendto", io_appendto},
-  {"closefile",   io_close},
-  {"flush",     io_flush},
-  {"openfile",   io_open},
-  {"read",     io_read},
-  {"readfrom", io_readfrom},
-  {"seek",     io_seek},
-  {"write",    io_write},
-  {"writeto",  io_writeto}
-};
 
 
-static void openwithcontrol (lua_State *L) {
-  IOCtrl *ctrl = (IOCtrl *)lua_newuserdata(L, sizeof(IOCtrl));
-  unsigned int i;
-  ctrl->iotag = lua_newtag(L);
-  ctrl->closedtag = lua_newtag(L);
-  for (i=0; i<sizeof(iolibtag)/sizeof(iolibtag[0]); i++) {
-    /* put `ctrl' as upvalue for these functions */
-    lua_pushvalue(L, -1);
-    lua_pushcclosure(L, iolibtag[i].func, 1);
-    lua_setglobal(L, iolibtag[i].name);
-  }
-  /* create references to variable names */
-  lua_pushstring(L, filenames[INFILE]);
-  ctrl->ref[INFILE] = lua_ref(L, 1);
-  lua_pushstring(L, filenames[OUTFILE]);
-  ctrl->ref[OUTFILE] = lua_ref(L, 1);
-  /* predefined file handles */
-  setfile(L, ctrl, stdin, INFILE);
-  setfile(L, ctrl, stdout, OUTFILE);
-  setfilebyname(L, ctrl, stdin, "_STDIN");
-  setfilebyname(L, ctrl, stdout, "_STDOUT");
-  setfilebyname(L, ctrl, stderr, "_STDERR");
-  /* close files when collected */
-  lua_pushcclosure(L, file_collect, 1);  /* pops `ctrl' from stack */
-  lua_settagmethod(L, ctrl->iotag, "gc");
-}
-
-
-LUALIB_API void lua_iolibopen (lua_State *L) {
-  luaL_openl(L, iolib);
-  openwithcontrol(L);
+LUALIB_API int luaopen_io (lua_State *L) {
+  luaL_openlib(L, LUA_OSLIBNAME, syslib, 0);
+  createmeta(L);
+  lua_pushvalue(L, -1);
+  luaL_openlib(L, LUA_IOLIBNAME, iolib, 1);
+  /* put predefined file handles into `io' table */
+  registerfile(L, stdin, "stdin", IO_INPUT);
+  registerfile(L, stdout, "stdout", IO_OUTPUT);
+  registerfile(L, stderr, "stderr", NULL);
+  return 1;
 }
 
diff --git a/src/lib/lmathlib.c b/src/lib/lmathlib.c
index c062cf49..f074a56e 100644
--- a/src/lib/lmathlib.c
+++ b/src/lib/lmathlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmathlib.c,v 1.32 2000/10/31 13:10:24 roberto Exp $
+** $Id: lmathlib.c,v 1.56 2003/03/11 12:30:37 roberto Exp $
 ** Standard mathematical library
 ** See Copyright Notice in lua.h
 */
@@ -8,6 +8,8 @@
 #include <stdlib.h>
 #include <math.h>
 
+#define lmathlib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
@@ -21,117 +23,117 @@
 
 
 /*
-** If you want Lua to operate in radians (instead of degrees),
-** define RADIANS
+** If you want Lua to operate in degrees (instead of radians),
+** define USE_DEGREES
 */
-#ifdef RADIANS
-#define FROMRAD(a)	(a)
-#define TORAD(a)	(a)
-#else
+#ifdef USE_DEGREES
 #define FROMRAD(a)	((a)/RADIANS_PER_DEGREE)
 #define TORAD(a)	((a)*RADIANS_PER_DEGREE)
+#else
+#define FROMRAD(a)	(a)
+#define TORAD(a)	(a)
 #endif
 
 
 static int math_abs (lua_State *L) {
-  lua_pushnumber(L, fabs(luaL_check_number(L, 1)));
+  lua_pushnumber(L, fabs(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_sin (lua_State *L) {
-  lua_pushnumber(L, sin(TORAD(luaL_check_number(L, 1))));
+  lua_pushnumber(L, sin(TORAD(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_cos (lua_State *L) {
-  lua_pushnumber(L, cos(TORAD(luaL_check_number(L, 1))));
+  lua_pushnumber(L, cos(TORAD(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_tan (lua_State *L) {
-  lua_pushnumber(L, tan(TORAD(luaL_check_number(L, 1))));
+  lua_pushnumber(L, tan(TORAD(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_asin (lua_State *L) {
-  lua_pushnumber(L, FROMRAD(asin(luaL_check_number(L, 1))));
+  lua_pushnumber(L, FROMRAD(asin(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_acos (lua_State *L) {
-  lua_pushnumber(L, FROMRAD(acos(luaL_check_number(L, 1))));
+  lua_pushnumber(L, FROMRAD(acos(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_atan (lua_State *L) {
-  lua_pushnumber(L, FROMRAD(atan(luaL_check_number(L, 1))));
+  lua_pushnumber(L, FROMRAD(atan(luaL_checknumber(L, 1))));
   return 1;
 }
 
 static int math_atan2 (lua_State *L) {
-  lua_pushnumber(L, FROMRAD(atan2(luaL_check_number(L, 1), luaL_check_number(L, 2))));
+  lua_pushnumber(L, FROMRAD(atan2(luaL_checknumber(L, 1), luaL_checknumber(L, 2))));
   return 1;
 }
 
 static int math_ceil (lua_State *L) {
-  lua_pushnumber(L, ceil(luaL_check_number(L, 1)));
+  lua_pushnumber(L, ceil(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_floor (lua_State *L) {
-  lua_pushnumber(L, floor(luaL_check_number(L, 1)));
+  lua_pushnumber(L, floor(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_mod (lua_State *L) {
-  lua_pushnumber(L, fmod(luaL_check_number(L, 1), luaL_check_number(L, 2)));
+  lua_pushnumber(L, fmod(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));
   return 1;
 }
 
 static int math_sqrt (lua_State *L) {
-  lua_pushnumber(L, sqrt(luaL_check_number(L, 1)));
+  lua_pushnumber(L, sqrt(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_pow (lua_State *L) {
-  lua_pushnumber(L, pow(luaL_check_number(L, 1), luaL_check_number(L, 2)));
+  lua_pushnumber(L, pow(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));
   return 1;
 }
 
 static int math_log (lua_State *L) {
-  lua_pushnumber(L, log(luaL_check_number(L, 1)));
+  lua_pushnumber(L, log(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_log10 (lua_State *L) {
-  lua_pushnumber(L, log10(luaL_check_number(L, 1)));
+  lua_pushnumber(L, log10(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_exp (lua_State *L) {
-  lua_pushnumber(L, exp(luaL_check_number(L, 1)));
+  lua_pushnumber(L, exp(luaL_checknumber(L, 1)));
   return 1;
 }
 
 static int math_deg (lua_State *L) {
-  lua_pushnumber(L, luaL_check_number(L, 1)/RADIANS_PER_DEGREE);
+  lua_pushnumber(L, luaL_checknumber(L, 1)/RADIANS_PER_DEGREE);
   return 1;
 }
 
 static int math_rad (lua_State *L) {
-  lua_pushnumber(L, luaL_check_number(L, 1)*RADIANS_PER_DEGREE);
+  lua_pushnumber(L, luaL_checknumber(L, 1)*RADIANS_PER_DEGREE);
   return 1;
 }
 
 static int math_frexp (lua_State *L) {
   int e;
-  lua_pushnumber(L, frexp(luaL_check_number(L, 1), &e));
+  lua_pushnumber(L, frexp(luaL_checknumber(L, 1), &e));
   lua_pushnumber(L, e);
   return 2;
 }
 
 static int math_ldexp (lua_State *L) {
-  lua_pushnumber(L, ldexp(luaL_check_number(L, 1), luaL_check_int(L, 2)));
+  lua_pushnumber(L, ldexp(luaL_checknumber(L, 1), luaL_checkint(L, 2)));
   return 1;
 }
 
@@ -139,10 +141,10 @@ static int math_ldexp (lua_State *L) {
 
 static int math_min (lua_State *L) {
   int n = lua_gettop(L);  /* number of arguments */
-  double dmin = luaL_check_number(L, 1);
+  lua_Number dmin = luaL_checknumber(L, 1);
   int i;
   for (i=2; i<=n; i++) {
-    double d = luaL_check_number(L, i);
+    lua_Number d = luaL_checknumber(L, i);
     if (d < dmin)
       dmin = d;
   }
@@ -153,10 +155,10 @@ static int math_min (lua_State *L) {
 
 static int math_max (lua_State *L) {
   int n = lua_gettop(L);  /* number of arguments */
-  double dmax = luaL_check_number(L, 1);
+  lua_Number dmax = luaL_checknumber(L, 1);
   int i;
   for (i=2; i<=n; i++) {
-    double d = luaL_check_number(L, i);
+    lua_Number d = luaL_checknumber(L, i);
     if (d > dmax)
       dmax = d;
   }
@@ -166,73 +168,79 @@ static int math_max (lua_State *L) {
 
 
 static int math_random (lua_State *L) {
-  /* the '%' avoids the (rare) case of r==1, and is needed also because on
-     some systems (SunOS!) "rand()" may return a value larger than RAND_MAX */
-  double r = (double)(rand()%RAND_MAX) / (double)RAND_MAX;
+  /* the `%' avoids the (rare) case of r==1, and is needed also because on
+     some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
+  lua_Number r = (lua_Number)(rand()%RAND_MAX) / (lua_Number)RAND_MAX;
   switch (lua_gettop(L)) {  /* check number of arguments */
     case 0: {  /* no arguments */
       lua_pushnumber(L, r);  /* Number between 0 and 1 */
       break;
     }
     case 1: {  /* only upper limit */
-      int u = luaL_check_int(L, 1);
-      luaL_arg_check(L, 1<=u, 1, "interval is empty");
-      lua_pushnumber(L, (int)(r*u)+1);  /* integer between 1 and `u' */
+      int u = luaL_checkint(L, 1);
+      luaL_argcheck(L, 1<=u, 1, "interval is empty");
+      lua_pushnumber(L, (int)floor(r*u)+1);  /* int between 1 and `u' */
       break;
     }
     case 2: {  /* lower and upper limits */
-      int l = luaL_check_int(L, 1);
-      int u = luaL_check_int(L, 2);
-      luaL_arg_check(L, l<=u, 2, "interval is empty");
-      lua_pushnumber(L, (int)(r*(u-l+1))+l);  /* integer between `l' and `u' */
+      int l = luaL_checkint(L, 1);
+      int u = luaL_checkint(L, 2);
+      luaL_argcheck(L, l<=u, 2, "interval is empty");
+      lua_pushnumber(L, (int)floor(r*(u-l+1))+l);  /* int between `l' and `u' */
       break;
     }
-    default: lua_error(L, "wrong number of arguments");
+    default: return luaL_error(L, "wrong number of arguments");
   }
   return 1;
 }
 
 
 static int math_randomseed (lua_State *L) {
-  srand(luaL_check_int(L, 1));
+  srand(luaL_checkint(L, 1));
   return 0;
 }
 
 
-static const struct luaL_reg mathlib[] = {
-{"abs",   math_abs},
-{"sin",   math_sin},
-{"cos",   math_cos},
-{"tan",   math_tan},
-{"asin",  math_asin},
-{"acos",  math_acos},
-{"atan",  math_atan},
-{"atan2", math_atan2},
-{"ceil",  math_ceil},
-{"floor", math_floor},
-{"mod",   math_mod},
-{"frexp", math_frexp},
-{"ldexp", math_ldexp},
-{"sqrt",  math_sqrt},
-{"min",   math_min},
-{"max",   math_max},
-{"log",   math_log},
-{"log10", math_log10},
-{"exp",   math_exp},
-{"deg",   math_deg},
-{"rad",   math_rad},
-{"random",     math_random},
-{"randomseed", math_randomseed}
+static const luaL_reg mathlib[] = {
+  {"abs",   math_abs},
+  {"sin",   math_sin},
+  {"cos",   math_cos},
+  {"tan",   math_tan},
+  {"asin",  math_asin},
+  {"acos",  math_acos},
+  {"atan",  math_atan},
+  {"atan2", math_atan2},
+  {"ceil",  math_ceil},
+  {"floor", math_floor},
+  {"mod",   math_mod},
+  {"frexp", math_frexp},
+  {"ldexp", math_ldexp},
+  {"sqrt",  math_sqrt},
+  {"min",   math_min},
+  {"max",   math_max},
+  {"log",   math_log},
+  {"log10", math_log10},
+  {"exp",   math_exp},
+  {"deg",   math_deg},
+  {"pow",   math_pow},
+  {"rad",   math_rad},
+  {"random",     math_random},
+  {"randomseed", math_randomseed},
+  {NULL, NULL}
 };
 
+
 /*
 ** Open math library
 */
-LUALIB_API void lua_mathlibopen (lua_State *L) {
-  luaL_openl(L, mathlib);
-  lua_pushcfunction(L, math_pow);
-  lua_settagmethod(L, LUA_TNUMBER, "pow");
+LUALIB_API int luaopen_math (lua_State *L) {
+  luaL_openlib(L, LUA_MATHLIBNAME, mathlib, 0);
+  lua_pushliteral(L, "pi");
   lua_pushnumber(L, PI);
-  lua_setglobal(L, "PI");
+  lua_settable(L, -3);
+  lua_pushliteral(L, "__pow");
+  lua_pushcfunction(L, math_pow);
+  lua_settable(L, LUA_GLOBALSINDEX);
+  return 1;
 }
 
diff --git a/src/lib/loadlib.c b/src/lib/loadlib.c
new file mode 100644
index 00000000..ac4d697a
--- /dev/null
+++ b/src/lib/loadlib.c
@@ -0,0 +1,205 @@
+/*
+** $Id: loadlib.c,v 1.4 2003/04/07 20:11:53 roberto Exp $
+** Dynamic library loader for Lua
+** See Copyright Notice in lua.h
+*
+* This  Lua library  exports a  single function,  called loadlib,  which is
+* called from Lua  as loadlib(lib,init), where lib is the  full name of the
+* library to be  loaded (including the complete path) and  init is the name
+* of a function  to be called after the library  is loaded. Typically, this
+* function will register other functions,  thus making the complete library
+* available  to Lua.  The init  function is  *not* automatically  called by
+* loadlib. Instead,  loadlib returns  the init function  as a  Lua function
+* that the client  can call when it  thinks is appropriate. In  the case of
+* errors,  loadlib  returns  nil  and two  strings  describing  the  error.
+* The  first string  is  supplied by  the operating  system;  it should  be
+* informative and useful  for error messages. The second  string is "open",
+* "init", or  "absent" to identify  the error and is  meant to be  used for
+* making  decisions without  having to  look into  the first  string (whose
+* format is system-dependent).
+*
+* This module contains  an implementation of loadlib for  Unix systems that
+* have dlfcn, an implementation for Windows,  and a stub for other systems.
+* See  the list  at  the end  of  this  file for  some  links to  available
+* implementations of dlfcn  and interfaces to other  native dynamic loaders
+* on top of which loadlib could be implemented.
+*
+*/
+
+#include "lua.h"
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#undef LOADLIB
+
+
+#ifdef USE_DLOPEN
+#define LOADLIB
+/*
+* This is an implementation of loadlib based on the dlfcn interface.
+* The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
+* NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
+* as an emulation layer on top of native functions.
+*/
+
+#include <dlfcn.h>
+
+static int loadlib(lua_State *L)
+{
+ const char *path=luaL_checkstring(L,1);
+ const char *init=luaL_checkstring(L,2);
+ void *lib=dlopen(path,RTLD_NOW);
+ if (lib!=NULL)
+ {
+  lua_CFunction f=(lua_CFunction) dlsym(lib,init);
+  if (f!=NULL)
+  {
+   lua_pushlightuserdata(L,lib);
+   lua_pushcclosure(L,f,1);
+   return 1;
+  }
+ }
+ /* else return appropriate error messages */
+ lua_pushnil(L);
+ lua_pushstring(L,dlerror());
+ lua_pushstring(L,(lib!=NULL) ? "init" : "open");
+ if (lib!=NULL) dlclose(lib);
+ return 3;
+}
+
+#endif
+
+
+
+/*
+** In Windows, default is to use dll; otherwise, default is not to use dll
+*/
+#ifndef USE_DLL
+#ifdef _WIN32
+#define USE_DLL	1
+#else
+#define USE_DLL	0
+#endif
+#endif
+
+
+#if USE_DLL
+#define LOADLIB
+/*
+* This is an implementation of loadlib for Windows using native functions.
+*/
+
+#include <windows.h>
+
+static void pusherror(lua_State *L)
+{
+ int error=GetLastError();
+ char buffer[128];
+ if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
+	0, error, 0, buffer, sizeof(buffer), 0))
+  lua_pushstring(L,buffer);
+ else
+  lua_pushfstring(L,"system error %d\n",error);
+}
+
+static int loadlib(lua_State *L)
+{
+ const char *path=luaL_checkstring(L,1);
+ const char *init=luaL_checkstring(L,2);
+ HINSTANCE lib=LoadLibrary(path);
+ if (lib!=NULL)
+ {
+  lua_CFunction f=(lua_CFunction) GetProcAddress(lib,init);
+  if (f!=NULL)
+  {
+   lua_pushlightuserdata(L,lib);
+   lua_pushcclosure(L,f,1);
+   return 1;
+  }
+ }
+ lua_pushnil(L);
+ pusherror(L);
+ lua_pushstring(L,(lib!=NULL) ? "init" : "open");
+ if (lib!=NULL) FreeLibrary(lib);
+ return 3;
+}
+
+#endif
+
+
+
+#ifndef LOADLIB
+/* Fallback for other systems */
+
+/*
+** Those systems support dlopen, so they should have defined USE_DLOPEN.
+** The default (no)implementation gives them a special error message.
+*/
+#ifdef linux
+#define LOADLIB
+#endif
+
+#ifdef sun
+#define LOADLIB
+#endif
+
+#ifdef sgi
+#define LOADLIB
+#endif
+
+#ifdef BSD
+#define LOADLIB
+#endif
+
+#ifdef _WIN32
+#define LOADLIB
+#endif
+
+#ifdef LOADLIB
+#undef LOADLIB
+#define LOADLIB	"`loadlib' not installed (check your Lua configuration)"
+#else
+#define LOADLIB	"`loadlib' not supported"
+#endif
+
+static int loadlib(lua_State *L)
+{
+ lua_pushnil(L);
+ lua_pushliteral(L,LOADLIB);
+ lua_pushliteral(L,"absent");
+ return 3;
+}
+#endif
+
+LUALIB_API int luaopen_loadlib (lua_State *L)
+{
+ lua_register(L,"loadlib",loadlib);
+ return 0;
+}
+
+/*
+* Here are some links to available implementations of dlfcn and
+* interfaces to other native dynamic loaders on top of which loadlib
+* could be implemented. Please send contributions and corrections to us.
+*
+* AIX
+* Starting with AIX 4.2, dlfcn is included in the base OS.
+* There is also an emulation package available.
+* http://www.faqs.org/faqs/aix-faq/part4/section-21.html
+*
+* HPUX 
+* HPUX 11 has dlfcn. For HPUX 10 use shl_*.
+* http://www.geda.seul.org/mailinglist/geda-dev37/msg00094.html
+* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
+*
+* Macintosh, Windows
+* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
+*
+* Mac OS X/Darwin
+* http://www.opendarwin.org/projects/dlcompat/
+*
+* GLIB has wrapper code for BeOS, OS2, Unix and Windows
+* http://cvs.gnome.org/lxr/source/glib/gmodule/
+*
+*/
diff --git a/src/lib/lstrlib.c b/src/lib/lstrlib.c
index 8f286982..8752e3ab 100644
--- a/src/lib/lstrlib.c
+++ b/src/lib/lstrlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.56 2000/10/27 16:15:53 roberto Exp $
+** $Id: lstrlib.c,v 1.98 2003/04/03 13:35:34 roberto Exp $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -11,37 +11,47 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define lstrlib_c
+
 #include "lua.h"
 
 #include "lauxlib.h"
 #include "lualib.h"
 
 
+/* macro to `unsign' a character */
+#ifndef uchar
+#define uchar(c)        ((unsigned char)(c))
+#endif
+
+
+typedef long sint32;	/* a signed version for size_t */
+
 
 static int str_len (lua_State *L) {
   size_t l;
-  luaL_check_lstr(L, 1, &l);
-  lua_pushnumber(L, l);
+  luaL_checklstring(L, 1, &l);
+  lua_pushnumber(L, (lua_Number)l);
   return 1;
 }
 
 
-static long posrelat (long pos, size_t len) {
+static sint32 posrelat (sint32 pos, size_t len) {
   /* relative string position: negative means back from end */
-  return (pos>=0) ? pos : (long)len+pos+1;
+  return (pos>=0) ? pos : (sint32)len+pos+1;
 }
 
 
 static int str_sub (lua_State *L) {
   size_t l;
-  const char *s = luaL_check_lstr(L, 1, &l);
-  long start = posrelat(luaL_check_long(L, 2), l);
-  long end = posrelat(luaL_opt_long(L, 3, -1), l);
+  const char *s = luaL_checklstring(L, 1, &l);
+  sint32 start = posrelat(luaL_checklong(L, 2), l);
+  sint32 end = posrelat(luaL_optlong(L, 3, -1), l);
   if (start < 1) start = 1;
-  if (end > (long)l) end = l;
+  if (end > (sint32)l) end = (sint32)l;
   if (start <= end)
     lua_pushlstring(L, s+start-1, end-start+1);
-  else lua_pushstring(L, "");
+  else lua_pushliteral(L, "");
   return 1;
 }
 
@@ -50,10 +60,10 @@ static int str_lower (lua_State *L) {
   size_t l;
   size_t i;
   luaL_Buffer b;
-  const char *s = luaL_check_lstr(L, 1, &l);
+  const char *s = luaL_checklstring(L, 1, &l);
   luaL_buffinit(L, &b);
   for (i=0; i<l; i++)
-    luaL_putchar(&b, tolower((unsigned char)(s[i])));
+    luaL_putchar(&b, tolower(uchar(s[i])));
   luaL_pushresult(&b);
   return 1;
 }
@@ -63,10 +73,10 @@ static int str_upper (lua_State *L) {
   size_t l;
   size_t i;
   luaL_Buffer b;
-  const char *s = luaL_check_lstr(L, 1, &l);
+  const char *s = luaL_checklstring(L, 1, &l);
   luaL_buffinit(L, &b);
   for (i=0; i<l; i++)
-    luaL_putchar(&b, toupper((unsigned char)(s[i])));
+    luaL_putchar(&b, toupper(uchar(s[i])));
   luaL_pushresult(&b);
   return 1;
 }
@@ -74,8 +84,8 @@ static int str_upper (lua_State *L) {
 static int str_rep (lua_State *L) {
   size_t l;
   luaL_Buffer b;
-  const char *s = luaL_check_lstr(L, 1, &l);
-  int n = luaL_check_int(L, 2);
+  const char *s = luaL_checklstring(L, 1, &l);
+  int n = luaL_checkint(L, 2);
   luaL_buffinit(L, &b);
   while (n-- > 0)
     luaL_addlstring(&b, s, l);
@@ -86,10 +96,11 @@ static int str_rep (lua_State *L) {
 
 static int str_byte (lua_State *L) {
   size_t l;
-  const char *s = luaL_check_lstr(L, 1, &l);
-  long pos = posrelat(luaL_opt_long(L, 2, 1), l);
-  luaL_arg_check(L, 0<pos && (size_t)pos<=l, 2,  "out of range");
-  lua_pushnumber(L, (unsigned char)s[pos-1]);
+  const char *s = luaL_checklstring(L, 1, &l);
+  sint32 pos = posrelat(luaL_optlong(L, 2, 1), l);
+  if (pos <= 0 || (size_t)(pos) > l)  /* index out of range? */
+    return 0;  /* no answer */
+  lua_pushnumber(L, uchar(s[pos-1]));
   return 1;
 }
 
@@ -100,15 +111,33 @@ static int str_char (lua_State *L) {
   luaL_Buffer b;
   luaL_buffinit(L, &b);
   for (i=1; i<=n; i++) {
-    int c = luaL_check_int(L, i);
-    luaL_arg_check(L, (unsigned char)c == c, i, "invalid value");
-    luaL_putchar(&b, (unsigned char)c);
+    int c = luaL_checkint(L, i);
+    luaL_argcheck(L, uchar(c) == c, i, "invalid value");
+    luaL_putchar(&b, uchar(c));
   }
   luaL_pushresult(&b);
   return 1;
 }
 
 
+static int writer (lua_State *L, const void* b, size_t size, void* B) {
+  (void)L;
+  luaL_addlstring((luaL_Buffer*) B, (const char *)b, size);
+  return 1;
+}
+
+
+static int str_dump (lua_State *L) {
+  luaL_Buffer b;
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  luaL_buffinit(L,&b);
+  if (!lua_dump(L, writer, &b))
+    luaL_error(L, "unable to dump given function");
+  luaL_pushresult(&b);
+  return 1;
+}
+
+
 
 /*
 ** {======================================================
@@ -121,51 +150,61 @@ static int str_char (lua_State *L) {
 #endif
 
 
-struct Capture {
-  const char *src_end;  /* end ('\0') of source string */
+#define CAP_UNFINISHED	(-1)
+#define CAP_POSITION	(-2)
+
+typedef struct MatchState {
+  const char *src_init;  /* init of source string */
+  const char *src_end;  /* end (`\0') of source string */
+  lua_State *L;
   int level;  /* total number of captures (finished or unfinished) */
   struct {
     const char *init;
-    long len;  /* -1 signals unfinished capture */
+    sint32 len;
   } capture[MAX_CAPTURES];
-};
+} MatchState;
 
 
 #define ESC		'%'
 #define SPECIALS	"^$*+?.([%-"
 
 
-static int check_capture (lua_State *L, int l, struct Capture *cap) {
+static int check_capture (MatchState *ms, int l) {
   l -= '1';
-  if (!(0 <= l && l < cap->level && cap->capture[l].len != -1))
-    lua_error(L, "invalid capture index");
+  if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
+    return luaL_error(ms->L, "invalid capture index");
   return l;
 }
 
 
-static int capture_to_close (lua_State *L, struct Capture *cap) {
-  int level = cap->level;
+static int capture_to_close (MatchState *ms) {
+  int level = ms->level;
   for (level--; level>=0; level--)
-    if (cap->capture[level].len == -1) return level;
-  lua_error(L, "invalid pattern capture");
-  return 0;  /* to avoid warnings */
+    if (ms->capture[level].len == CAP_UNFINISHED) return level;
+  return luaL_error(ms->L, "invalid pattern capture");
 }
 
 
-const char *luaI_classend (lua_State *L, const char *p) {
+static const char *luaI_classend (MatchState *ms, const char *p) {
   switch (*p++) {
-    case ESC:
-      if (*p == '\0') lua_error(L, "malformed pattern (ends with `%')");
+    case ESC: {
+      if (*p == '\0')
+        luaL_error(ms->L, "malformed pattern (ends with `%')");
       return p+1;
-    case '[':
+    }
+    case '[': {
       if (*p == '^') p++;
-      do {  /* look for a ']' */
-        if (*p == '\0') lua_error(L, "malformed pattern (missing `]')");
-        if (*(p++) == ESC && *p != '\0') p++;  /* skip escapes (e.g. '%]') */
+      do {  /* look for a `]' */
+        if (*p == '\0')
+          luaL_error(ms->L, "malformed pattern (missing `]')");
+        if (*(p++) == ESC && *p != '\0')
+          p++;  /* skip escapes (e.g. `%]') */
       } while (*p != ']');
       return p+1;
-    default:
+    }
+    default: {
       return p;
+    }
   }
 }
 
@@ -182,66 +221,59 @@ static int match_class (int c, int cl) {
     case 'u' : res = isupper(c); break;
     case 'w' : res = isalnum(c); break;
     case 'x' : res = isxdigit(c); break;
-    case 'z' : res = (c == '\0'); break;
+    case 'z' : res = (c == 0); break;
     default: return (cl == c);
   }
   return (islower(cl) ? res : !res);
 }
 
 
-
-static int matchbracketclass (int c, const char *p, const char *endclass) {
+static int matchbracketclass (int c, const char *p, const char *ec) {
   int sig = 1;
   if (*(p+1) == '^') {
     sig = 0;
-    p++;  /* skip the '^' */
+    p++;  /* skip the `^' */
   }
-  while (++p < endclass) {
+  while (++p < ec) {
     if (*p == ESC) {
       p++;
-      if (match_class(c, (unsigned char)*p))
+      if (match_class(c, *p))
         return sig;
     }
-    else if ((*(p+1) == '-') && (p+2 < endclass)) {
+    else if ((*(p+1) == '-') && (p+2 < ec)) {
       p+=2;
-      if ((int)(unsigned char)*(p-2) <= c && c <= (int)(unsigned char)*p)
+      if (uchar(*(p-2)) <= c && c <= uchar(*p))
         return sig;
     }
-    else if ((int)(unsigned char)*p == c) return sig;
+    else if (uchar(*p) == c) return sig;
   }
   return !sig;
 }
 
 
-
-int luaI_singlematch (int c, const char *p, const char *ep) {
+static int luaI_singlematch (int c, const char *p, const char *ep) {
   switch (*p) {
-    case '.':  /* matches any char */
-      return 1;
-    case ESC:
-      return match_class(c, (unsigned char)*(p+1));
-    case '[':
-      return matchbracketclass(c, p, ep-1);
-    default:
-      return ((unsigned char)*p == c);
+    case '.': return 1;  /* matches any char */
+    case ESC: return match_class(c, *(p+1));
+    case '[': return matchbracketclass(c, p, ep-1);
+    default:  return (uchar(*p) == c);
   }
 }
 
 
-static const char *match (lua_State *L, const char *s, const char *p,
-                          struct Capture *cap);
+static const char *match (MatchState *ms, const char *s, const char *p);
 
 
-static const char *matchbalance (lua_State *L, const char *s, const char *p,
-                                 struct Capture *cap) {
+static const char *matchbalance (MatchState *ms, const char *s,
+                                   const char *p) {
   if (*p == 0 || *(p+1) == 0)
-    lua_error(L, "unbalanced pattern");
+    luaL_error(ms->L, "unbalanced pattern");
   if (*s != *p) return NULL;
   else {
     int b = *p;
     int e = *(p+1);
     int cont = 1;
-    while (++s < cap->src_end) {
+    while (++s < ms->src_end) {
       if (*s == e) {
         if (--cont == 0) return s+1;
       }
@@ -252,14 +284,14 @@ static const char *matchbalance (lua_State *L, const char *s, const char *p,
 }
 
 
-static const char *max_expand (lua_State *L, const char *s, const char *p,
-                               const char *ep, struct Capture *cap) {
-  long i = 0;  /* counts maximum expand for item */
-  while ((s+i)<cap->src_end && luaI_singlematch((unsigned char)*(s+i), p, ep))
+static const char *max_expand (MatchState *ms, const char *s,
+                                 const char *p, const char *ep) {
+  sint32 i = 0;  /* counts maximum expand for item */
+  while ((s+i)<ms->src_end && luaI_singlematch(uchar(*(s+i)), p, ep))
     i++;
   /* keeps trying to match with the maximum repetitions */
   while (i>=0) {
-    const char *res = match(L, (s+i), ep+1, cap);
+    const char *res = match(ms, (s+i), ep+1);
     if (res) return res;
     i--;  /* else didn't match; reduce 1 repetition to try again */
   }
@@ -267,100 +299,126 @@ static const char *max_expand (lua_State *L, const char *s, const char *p,
 }
 
 
-static const char *min_expand (lua_State *L, const char *s, const char *p,
-                               const char *ep, struct Capture *cap) {
+static const char *min_expand (MatchState *ms, const char *s,
+                                 const char *p, const char *ep) {
   for (;;) {
-    const char *res = match(L, s, ep+1, cap);
+    const char *res = match(ms, s, ep+1);
     if (res != NULL)
       return res;
-    else if (s<cap->src_end && luaI_singlematch((unsigned char)*s, p, ep))
+    else if (s<ms->src_end && luaI_singlematch(uchar(*s), p, ep))
       s++;  /* try with one more repetition */
     else return NULL;
   }
 }
 
 
-static const char *start_capture (lua_State *L, const char *s, const char *p,
-                                  struct Capture *cap) {
+static const char *start_capture (MatchState *ms, const char *s,
+                                    const char *p, int what) {
   const char *res;
-  int level = cap->level;
-  if (level >= MAX_CAPTURES) lua_error(L, "too many captures");
-  cap->capture[level].init = s;
-  cap->capture[level].len = -1;
-  cap->level = level+1;
-  if ((res=match(L, s, p+1, cap)) == NULL)  /* match failed? */
-    cap->level--;  /* undo capture */
+  int level = ms->level;
+  if (level >= MAX_CAPTURES) luaL_error(ms->L, "too many captures");
+  ms->capture[level].init = s;
+  ms->capture[level].len = what;
+  ms->level = level+1;
+  if ((res=match(ms, s, p)) == NULL)  /* match failed? */
+    ms->level--;  /* undo capture */
   return res;
 }
 
 
-static const char *end_capture (lua_State *L, const char *s, const char *p,
-                                struct Capture *cap) {
-  int l = capture_to_close(L, cap);
+static const char *end_capture (MatchState *ms, const char *s,
+                                  const char *p) {
+  int l = capture_to_close(ms);
   const char *res;
-  cap->capture[l].len = s - cap->capture[l].init;  /* close capture */
-  if ((res = match(L, s, p+1, cap)) == NULL)  /* match failed? */
-    cap->capture[l].len = -1;  /* undo capture */
+  ms->capture[l].len = s - ms->capture[l].init;  /* close capture */
+  if ((res = match(ms, s, p)) == NULL)  /* match failed? */
+    ms->capture[l].len = CAP_UNFINISHED;  /* undo capture */
   return res;
 }
 
 
-static const char *match_capture (lua_State *L, const char *s, int level,
-                                  struct Capture *cap) {
-  int l = check_capture(L, level, cap);
-  size_t len = cap->capture[l].len;
-  if ((size_t)(cap->src_end-s) >= len &&
-      memcmp(cap->capture[l].init, s, len) == 0)
+static const char *match_capture (MatchState *ms, const char *s, int l) {
+  size_t len;
+  l = check_capture(ms, l);
+  len = ms->capture[l].len;
+  if ((size_t)(ms->src_end-s) >= len &&
+      memcmp(ms->capture[l].init, s, len) == 0)
     return s+len;
   else return NULL;
 }
 
 
-static const char *match (lua_State *L, const char *s, const char *p,
-                          struct Capture *cap) {
+static const char *match (MatchState *ms, const char *s, const char *p) {
   init: /* using goto's to optimize tail recursion */
   switch (*p) {
-    case '(':  /* start capture */
-      return start_capture(L, s, p, cap);
-    case ')':  /* end capture */
-      return end_capture(L, s, p, cap);
-    case ESC:  /* may be %[0-9] or %b */
-      if (isdigit((unsigned char)(*(p+1)))) {  /* capture? */
-        s = match_capture(L, s, *(p+1), cap);
-        if (s == NULL) return NULL;
-        p+=2; goto init;  /* else return match(L, s, p+2, cap) */
-      }
-      else if (*(p+1) == 'b') {  /* balanced string? */
-        s = matchbalance(L, s, p+2, cap);
-        if (s == NULL) return NULL;
-        p+=4; goto init;  /* else return match(L, s, p+4, cap); */
+    case '(': {  /* start capture */
+      if (*(p+1) == ')')  /* position capture? */
+        return start_capture(ms, s, p+2, CAP_POSITION);
+      else
+        return start_capture(ms, s, p+1, CAP_UNFINISHED);
+    }
+    case ')': {  /* end capture */
+      return end_capture(ms, s, p+1);
+    }
+    case ESC: {
+      switch (*(p+1)) {
+        case 'b': {  /* balanced string? */
+          s = matchbalance(ms, s, p+2);
+          if (s == NULL) return NULL;
+          p+=4; goto init;  /* else return match(ms, s, p+4); */
+        }
+        case 'f': {  /* frontier? */
+          const char *ep; char previous;
+          p += 2;
+          if (*p != '[')
+            luaL_error(ms->L, "missing `[' after `%%f' in pattern");
+          ep = luaI_classend(ms, p);  /* points to what is next */
+          previous = (s == ms->src_init) ? '\0' : *(s-1);
+          if (matchbracketclass(uchar(previous), p, ep-1) ||
+             !matchbracketclass(uchar(*s), p, ep-1)) return NULL;
+          p=ep; goto init;  /* else return match(ms, s, ep); */
+        }
+        default: {
+          if (isdigit(uchar(*(p+1)))) {  /* capture results (%0-%9)? */
+            s = match_capture(ms, s, *(p+1));
+            if (s == NULL) return NULL;
+            p+=2; goto init;  /* else return match(ms, s, p+2) */
+          }
+          goto dflt;  /* case default */
+        }
       }
-      else goto dflt;  /* case default */
-    case '\0':  /* end of pattern */
+    }
+    case '\0': {  /* end of pattern */
       return s;  /* match succeeded */
-    case '$':
-      if (*(p+1) == '\0')  /* is the '$' the last char in pattern? */
-        return (s == cap->src_end) ? s : NULL;  /* check end of string */
+    }
+    case '$': {
+      if (*(p+1) == '\0')  /* is the `$' the last char in pattern? */
+        return (s == ms->src_end) ? s : NULL;  /* check end of string */
       else goto dflt;
+    }
     default: dflt: {  /* it is a pattern item */
-      const char *ep = luaI_classend(L, p);  /* points to what is next */
-      int m = s<cap->src_end && luaI_singlematch((unsigned char)*s, p, ep);
+      const char *ep = luaI_classend(ms, p);  /* points to what is next */
+      int m = s<ms->src_end && luaI_singlematch(uchar(*s), p, ep);
       switch (*ep) {
         case '?': {  /* optional */
           const char *res;
-          if (m && ((res=match(L, s+1, ep+1, cap)) != NULL))
+          if (m && ((res=match(ms, s+1, ep+1)) != NULL))
             return res;
-          p=ep+1; goto init;  /* else return match(L, s, ep+1, cap); */
+          p=ep+1; goto init;  /* else return match(ms, s, ep+1); */
+        }
+        case '*': {  /* 0 or more repetitions */
+          return max_expand(ms, s, p, ep);
+        }
+        case '+': {  /* 1 or more repetitions */
+          return (m ? max_expand(ms, s+1, p, ep) : NULL);
+        }
+        case '-': {  /* 0 or more repetitions (minimum) */
+          return min_expand(ms, s, p, ep);
         }
-        case '*':  /* 0 or more repetitions */
-          return max_expand(L, s, p, ep, cap);
-        case '+':  /* 1 or more repetitions */
-          return (m ? max_expand(L, s+1, p, ep, cap) : NULL);
-        case '-':  /* 0 or more repetitions (minimum) */
-          return min_expand(L, s, p, ep, cap);
-        default:
+        default: {
           if (!m) return NULL;
-          s++; p=ep; goto init;  /* else return match(L, s+1, ep, cap); */
+          s++; p=ep; goto init;  /* else return match(ms, s+1, ep); */
+        }
       }
     }
   }
@@ -369,7 +427,7 @@ static const char *match (lua_State *L, const char *s, const char *p,
 
 
 static const char *lmemfind (const char *s1, size_t l1,
-                             const char *s2, size_t l2) {
+                               const char *s2, size_t l2) {
   if (l2 == 0) return s1;  /* empty strings are everywhere */
   else if (l2 > l1) return NULL;  /* avoids a negative `l1' */
   else {
@@ -390,54 +448,109 @@ static const char *lmemfind (const char *s1, size_t l1,
 }
 
 
-static int push_captures (lua_State *L, struct Capture *cap) {
+static void push_onecapture (MatchState *ms, int i) {
+  int l = ms->capture[i].len;
+  if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
+  if (l == CAP_POSITION)
+    lua_pushnumber(ms->L, (lua_Number)(ms->capture[i].init - ms->src_init + 1));
+  else
+    lua_pushlstring(ms->L, ms->capture[i].init, l);
+}
+
+
+static int push_captures (MatchState *ms, const char *s, const char *e) {
   int i;
-  luaL_checkstack(L, cap->level, "too many captures");
-  for (i=0; i<cap->level; i++) {
-    int l = cap->capture[i].len;
-    if (l == -1) lua_error(L, "unfinished capture");
-    lua_pushlstring(L, cap->capture[i].init, l);
+  luaL_checkstack(ms->L, ms->level, "too many captures");
+  if (ms->level == 0 && s) {  /* no explicit captures? */
+    lua_pushlstring(ms->L, s, e-s);  /* return whole match */
+    return 1;
+  }
+  else {  /* return all captures */
+    for (i=0; i<ms->level; i++)
+      push_onecapture(ms, i);
+    return ms->level;  /* number of strings pushed */
   }
-  return cap->level;  /* number of strings pushed */
 }
 
 
 static int str_find (lua_State *L) {
   size_t l1, l2;
-  const char *s = luaL_check_lstr(L, 1, &l1);
-  const char *p = luaL_check_lstr(L, 2, &l2);
-  long init = posrelat(luaL_opt_long(L, 3, 1), l1) - 1;
-  struct Capture cap;
-  luaL_arg_check(L, 0 <= init && (size_t)init <= l1, 3, "out of range");
-  if (lua_gettop(L) > 3 ||  /* extra argument? */
+  const char *s = luaL_checklstring(L, 1, &l1);
+  const char *p = luaL_checklstring(L, 2, &l2);
+  sint32 init = posrelat(luaL_optlong(L, 3, 1), l1) - 1;
+  if (init < 0) init = 0;
+  else if ((size_t)(init) > l1) init = (sint32)l1;
+  if (lua_toboolean(L, 4) ||  /* explicit request? */
       strpbrk(p, SPECIALS) == NULL) {  /* or no special characters? */
+    /* do a plain search */
     const char *s2 = lmemfind(s+init, l1-init, p, l2);
     if (s2) {
-      lua_pushnumber(L, s2-s+1);
-      lua_pushnumber(L, s2-s+l2);
+      lua_pushnumber(L, (lua_Number)(s2-s+1));
+      lua_pushnumber(L, (lua_Number)(s2-s+l2));
       return 2;
     }
   }
   else {
+    MatchState ms;
     int anchor = (*p == '^') ? (p++, 1) : 0;
     const char *s1=s+init;
-    cap.src_end = s+l1;
+    ms.L = L;
+    ms.src_init = s;
+    ms.src_end = s+l1;
     do {
       const char *res;
-      cap.level = 0;
-      if ((res=match(L, s1, p, &cap)) != NULL) {
-        lua_pushnumber(L, s1-s+1);  /* start */
-        lua_pushnumber(L, res-s);   /* end */
-        return push_captures(L, &cap) + 2;
+      ms.level = 0;
+      if ((res=match(&ms, s1, p)) != NULL) {
+        lua_pushnumber(L, (lua_Number)(s1-s+1));  /* start */
+        lua_pushnumber(L, (lua_Number)(res-s));   /* end */
+        return push_captures(&ms, NULL, 0) + 2;
       }
-    } while (s1++<cap.src_end && !anchor);
+    } while (s1++<ms.src_end && !anchor);
   }
   lua_pushnil(L);  /* not found */
   return 1;
 }
 
 
-static void add_s (lua_State *L, luaL_Buffer *b, struct Capture *cap) {
+static int gfind_aux (lua_State *L) {
+  MatchState ms;
+  const char *s = lua_tostring(L, lua_upvalueindex(1));
+  size_t ls = lua_strlen(L, lua_upvalueindex(1));
+  const char *p = lua_tostring(L, lua_upvalueindex(2));
+  const char *src;
+  ms.L = L;
+  ms.src_init = s;
+  ms.src_end = s+ls;
+  for (src = s + (size_t)lua_tonumber(L, lua_upvalueindex(3));
+       src <= ms.src_end;
+       src++) {
+    const char *e;
+    ms.level = 0;
+    if ((e = match(&ms, src, p)) != NULL) {
+      int newstart = e-s;
+      if (e == src) newstart++;  /* empty match? go at least one position */
+      lua_pushnumber(L, (lua_Number)newstart);
+      lua_replace(L, lua_upvalueindex(3));
+      return push_captures(&ms, src, e);
+    }
+  }
+  return 0;  /* not found */
+}
+
+
+static int gfind (lua_State *L) {
+  luaL_checkstring(L, 1);
+  luaL_checkstring(L, 2);
+  lua_settop(L, 2);
+  lua_pushnumber(L, 0);
+  lua_pushcclosure(L, gfind_aux, 3);
+  return 1;
+}
+
+
+static void add_s (MatchState *ms, luaL_Buffer *b,
+                   const char *s, const char *e) {
+  lua_State *L = ms->L;
   if (lua_isstring(L, 3)) {
     const char *news = lua_tostring(L, 3);
     size_t l = lua_strlen(L, 3);
@@ -447,11 +560,12 @@ static void add_s (lua_State *L, luaL_Buffer *b, struct Capture *cap) {
         luaL_putchar(b, news[i]);
       else {
         i++;  /* skip ESC */
-        if (!isdigit((unsigned char)news[i]))
+        if (!isdigit(uchar(news[i])))
           luaL_putchar(b, news[i]);
         else {
-          int level = check_capture(L, news[i], cap);
-          luaL_addlstring(b, cap->capture[level].init, cap->capture[level].len);
+          int level = check_capture(ms, news[i]);
+          push_onecapture(ms, level);
+          luaL_addvalue(b);  /* add capture to accumulated result */
         }
       }
     }
@@ -459,8 +573,8 @@ static void add_s (lua_State *L, luaL_Buffer *b, struct Capture *cap) {
   else {  /* is a function */
     int n;
     lua_pushvalue(L, 3);
-    n = push_captures(L, cap);
-    lua_rawcall(L, n, 1);
+    n = push_captures(ms, s, e);
+    lua_call(L, n, 1);
     if (lua_isstring(L, -1))
       luaL_addvalue(b);  /* add return to accumulated result */
     else
@@ -471,124 +585,155 @@ static void add_s (lua_State *L, luaL_Buffer *b, struct Capture *cap) {
 
 static int str_gsub (lua_State *L) {
   size_t srcl;
-  const char *src = luaL_check_lstr(L, 1, &srcl);
-  const char *p = luaL_check_string(L, 2);
-  int max_s = luaL_opt_int(L, 4, srcl+1);
+  const char *src = luaL_checklstring(L, 1, &srcl);
+  const char *p = luaL_checkstring(L, 2);
+  int max_s = luaL_optint(L, 4, srcl+1);
   int anchor = (*p == '^') ? (p++, 1) : 0;
   int n = 0;
-  struct Capture cap;
+  MatchState ms;
   luaL_Buffer b;
-  luaL_arg_check(L,
+  luaL_argcheck(L,
     lua_gettop(L) >= 3 && (lua_isstring(L, 3) || lua_isfunction(L, 3)),
     3, "string or function expected");
   luaL_buffinit(L, &b);
-  cap.src_end = src+srcl;
+  ms.L = L;
+  ms.src_init = src;
+  ms.src_end = src+srcl;
   while (n < max_s) {
     const char *e;
-    cap.level = 0;
-    e = match(L, src, p, &cap);
+    ms.level = 0;
+    e = match(&ms, src, p);
     if (e) {
       n++;
-      add_s(L, &b, &cap);
+      add_s(&ms, &b, src, e);
     }
     if (e && e>src) /* non empty match? */
       src = e;  /* skip it */
-    else if (src < cap.src_end)
+    else if (src < ms.src_end)
       luaL_putchar(&b, *src++);
     else break;
     if (anchor) break;
   }
-  luaL_addlstring(&b, src, cap.src_end-src);
+  luaL_addlstring(&b, src, ms.src_end-src);
   luaL_pushresult(&b);
-  lua_pushnumber(L, n);  /* number of substitutions */
+  lua_pushnumber(L, (lua_Number)n);  /* number of substitutions */
   return 2;
 }
 
 /* }====================================================== */
 
 
+/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
+#define MAX_ITEM	512
+/* maximum size of each format specification (such as '%-099.99d') */
+#define MAX_FORMAT	20
+
+
 static void luaI_addquoted (lua_State *L, luaL_Buffer *b, int arg) {
   size_t l;
-  const char *s = luaL_check_lstr(L, arg, &l);
+  const char *s = luaL_checklstring(L, arg, &l);
   luaL_putchar(b, '"');
   while (l--) {
     switch (*s) {
-      case '"':  case '\\':  case '\n':
+      case '"': case '\\': case '\n': {
         luaL_putchar(b, '\\');
         luaL_putchar(b, *s);
         break;
-      case '\0': luaL_addlstring(b, "\\000", 4); break;
-      default: luaL_putchar(b, *s);
+      }
+      case '\0': {
+        luaL_addlstring(b, "\\000", 4);
+        break;
+      }
+      default: {
+        luaL_putchar(b, *s);
+        break;
+      }
     }
     s++;
   }
   luaL_putchar(b, '"');
 }
 
-/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */
-#define MAX_ITEM	512
-/* maximum size of each format specification (such as '%-099.99d') */
-#define MAX_FORMAT	20
+
+static const char *scanformat (lua_State *L, const char *strfrmt,
+                                 char *form, int *hasprecision) {
+  const char *p = strfrmt;
+  while (strchr("-+ #0", *p)) p++;  /* skip flags */
+  if (isdigit(uchar(*p))) p++;  /* skip width */
+  if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
+  if (*p == '.') {
+    p++;
+    *hasprecision = 1;
+    if (isdigit(uchar(*p))) p++;  /* skip precision */
+    if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
+  }
+  if (isdigit(uchar(*p)))
+    luaL_error(L, "invalid format (width or precision too long)");
+  if (p-strfrmt+2 > MAX_FORMAT)  /* +2 to include `%' and the specifier */
+    luaL_error(L, "invalid format (too long)");
+  form[0] = '%';
+  strncpy(form+1, strfrmt, p-strfrmt+1);
+  form[p-strfrmt+2] = 0;
+  return p;
+}
+
 
 static int str_format (lua_State *L) {
   int arg = 1;
-  const char *strfrmt = luaL_check_string(L, arg);
+  size_t sfl;
+  const char *strfrmt = luaL_checklstring(L, arg, &sfl);
+  const char *strfrmt_end = strfrmt+sfl;
   luaL_Buffer b;
   luaL_buffinit(L, &b);
-  while (*strfrmt) {
+  while (strfrmt < strfrmt_end) {
     if (*strfrmt != '%')
       luaL_putchar(&b, *strfrmt++);
     else if (*++strfrmt == '%')
       luaL_putchar(&b, *strfrmt++);  /* %% */
     else { /* format item */
-      struct Capture cap;
-      char form[MAX_FORMAT];  /* to store the format ('%...') */
+      char form[MAX_FORMAT];  /* to store the format (`%...') */
       char buff[MAX_ITEM];  /* to store the formatted item */
-      const char *initf = strfrmt;
-      form[0] = '%';
-      if (isdigit((unsigned char)*initf) && *(initf+1) == '$') {
-        arg = *initf - '0';
-        initf += 2;  /* skip the 'n$' */
-      }
+      int hasprecision = 0;
+      if (isdigit(uchar(*strfrmt)) && *(strfrmt+1) == '$')
+        return luaL_error(L, "obsolete option (d$) to `format'");
       arg++;
-      cap.src_end = strfrmt+strlen(strfrmt)+1;
-      cap.level = 0;
-      strfrmt = match(L, initf, "[-+ #0]*(%d*)%.?(%d*)", &cap);
-      if (cap.capture[0].len > 2 || cap.capture[1].len > 2 ||  /* < 100? */
-          strfrmt-initf > MAX_FORMAT-2)
-        lua_error(L, "invalid format (width or precision too long)");
-      strncpy(form+1, initf, strfrmt-initf+1); /* +1 to include conversion */
-      form[strfrmt-initf+2] = 0;
+      strfrmt = scanformat(L, strfrmt, form, &hasprecision);
       switch (*strfrmt++) {
-        case 'c':  case 'd':  case 'i':
-          sprintf(buff, form, luaL_check_int(L, arg));
+        case 'c':  case 'd':  case 'i': {
+          sprintf(buff, form, luaL_checkint(L, arg));
           break;
-        case 'o':  case 'u':  case 'x':  case 'X':
-          sprintf(buff, form, (unsigned int)luaL_check_number(L, arg));
+        }
+        case 'o':  case 'u':  case 'x':  case 'X': {
+          sprintf(buff, form, (unsigned int)(luaL_checknumber(L, arg)));
           break;
-        case 'e':  case 'E': case 'f': case 'g': case 'G':
-          sprintf(buff, form, luaL_check_number(L, arg));
+        }
+        case 'e':  case 'E': case 'f':
+        case 'g': case 'G': {
+          sprintf(buff, form, luaL_checknumber(L, arg));
           break;
-        case 'q':
+        }
+        case 'q': {
           luaI_addquoted(L, &b, arg);
-          continue;  /* skip the "addsize" at the end */
+          continue;  /* skip the `addsize' at the end */
+        }
         case 's': {
           size_t l;
-          const char *s = luaL_check_lstr(L, arg, &l);
-          if (cap.capture[1].len == 0 && l >= 100) {
+          const char *s = luaL_checklstring(L, arg, &l);
+          if (!hasprecision && l >= 100) {
             /* no precision and string is too long to be formatted;
                keep original string */
             lua_pushvalue(L, arg);
             luaL_addvalue(&b);
-            continue;  /* skip the "addsize" at the end */
+            continue;  /* skip the `addsize' at the end */
           }
           else {
             sprintf(buff, form, s);
             break;
           }
         }
-        default:  /* also treat cases 'pnLlh' */
-          lua_error(L, "invalid option in `format'");
+        default: {  /* also treat cases `pnLlh' */
+          return luaL_error(L, "invalid option to `format'");
+        }
       }
       luaL_addlstring(&b, buff, strlen(buff));
     }
@@ -598,24 +743,28 @@ static int str_format (lua_State *L) {
 }
 
 
-static const struct luaL_reg strlib[] = {
-{"strlen", str_len},
-{"strsub", str_sub},
-{"strlower", str_lower},
-{"strupper", str_upper},
-{"strchar", str_char},
-{"strrep", str_rep},
-{"ascii", str_byte},  /* for compatibility with 3.0 and earlier */
-{"strbyte", str_byte},
-{"format", str_format},
-{"strfind", str_find},
-{"gsub", str_gsub}
+static const luaL_reg strlib[] = {
+  {"len", str_len},
+  {"sub", str_sub},
+  {"lower", str_lower},
+  {"upper", str_upper},
+  {"char", str_char},
+  {"rep", str_rep},
+  {"byte", str_byte},
+  {"format", str_format},
+  {"dump", str_dump},
+  {"find", str_find},
+  {"gfind", gfind},
+  {"gsub", str_gsub},
+  {NULL, NULL}
 };
 
 
 /*
 ** Open string library
 */
-LUALIB_API void lua_strlibopen (lua_State *L) {
-  luaL_openl(L, strlib);
+LUALIB_API int luaopen_string (lua_State *L) {
+  luaL_openlib(L, LUA_STRLIBNAME, strlib, 0);
+  return 1;
 }
+
diff --git a/src/lib/ltablib.c b/src/lib/ltablib.c
new file mode 100644
index 00000000..c9bb2d1b
--- /dev/null
+++ b/src/lib/ltablib.c
@@ -0,0 +1,250 @@
+/*
+** $Id: ltablib.c,v 1.21 2003/04/03 13:35:34 roberto Exp $
+** Library for Table Manipulation
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stddef.h>
+
+#define ltablib_c
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#define aux_getn(L,n)	(luaL_checktype(L, n, LUA_TTABLE), luaL_getn(L, n))
+
+
+static int luaB_foreachi (lua_State *L) {
+  int i;
+  int n = aux_getn(L, 1);
+  luaL_checktype(L, 2, LUA_TFUNCTION);
+  for (i=1; i<=n; i++) {
+    lua_pushvalue(L, 2);  /* function */
+    lua_pushnumber(L, (lua_Number)i);  /* 1st argument */
+    lua_rawgeti(L, 1, i);  /* 2nd argument */
+    lua_call(L, 2, 1);
+    if (!lua_isnil(L, -1))
+      return 1;
+    lua_pop(L, 1);  /* remove nil result */
+  }
+  return 0;
+}
+
+
+static int luaB_foreach (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_checktype(L, 2, LUA_TFUNCTION);
+  lua_pushnil(L);  /* first key */
+  for (;;) {
+    if (lua_next(L, 1) == 0)
+      return 0;
+    lua_pushvalue(L, 2);  /* function */
+    lua_pushvalue(L, -3);  /* key */
+    lua_pushvalue(L, -3);  /* value */
+    lua_call(L, 2, 1);
+    if (!lua_isnil(L, -1))
+      return 1;
+    lua_pop(L, 2);  /* remove value and result */
+  }
+}
+
+
+static int luaB_getn (lua_State *L) {
+  lua_pushnumber(L, (lua_Number)aux_getn(L, 1));
+  return 1;
+}
+
+
+static int luaB_setn (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  luaL_setn(L, 1, luaL_checkint(L, 2));
+  return 0;
+}
+
+
+static int luaB_tinsert (lua_State *L) {
+  int v = lua_gettop(L);  /* number of arguments */
+  int n = aux_getn(L, 1) + 1;
+  int pos;  /* where to insert new element */
+  if (v == 2)  /* called with only 2 arguments */
+    pos = n;  /* insert new element at the end */
+  else {
+    pos = luaL_checkint(L, 2);  /* 2nd argument is the position */
+    if (pos > n) n = pos;  /* `grow' array if necessary */
+    v = 3;  /* function may be called with more than 3 args */
+  }
+  luaL_setn(L, 1, n);  /* new size */
+  while (--n >= pos) {  /* move up elements */
+    lua_rawgeti(L, 1, n);
+    lua_rawseti(L, 1, n+1);  /* t[n+1] = t[n] */
+  }
+  lua_pushvalue(L, v);
+  lua_rawseti(L, 1, pos);  /* t[pos] = v */
+  return 0;
+}
+
+
+static int luaB_tremove (lua_State *L) {
+  int n = aux_getn(L, 1);
+  int pos = luaL_optint(L, 2, n);
+  if (n <= 0) return 0;  /* table is `empty' */
+  luaL_setn(L, 1, n-1);  /* t.n = n-1 */
+  lua_rawgeti(L, 1, pos);  /* result = t[pos] */
+  for ( ;pos<n; pos++) {
+    lua_rawgeti(L, 1, pos+1);
+    lua_rawseti(L, 1, pos);  /* t[pos] = t[pos+1] */
+  }
+  lua_pushnil(L);
+  lua_rawseti(L, 1, n);  /* t[n] = nil */
+  return 1;
+}
+
+
+static int str_concat (lua_State *L) {
+  luaL_Buffer b;
+  size_t lsep;
+  const char *sep = luaL_optlstring(L, 2, "", &lsep);
+  int i = luaL_optint(L, 3, 1);
+  int n = luaL_optint(L, 4, 0);
+  luaL_checktype(L, 1, LUA_TTABLE);
+  if (n == 0) n = luaL_getn(L, 1);
+  luaL_buffinit(L, &b);
+  for (; i <= n; i++) {
+    lua_rawgeti(L, 1, i);
+    luaL_argcheck(L, lua_isstring(L, -1), 1, "table contains non-strings");
+    luaL_addvalue(&b);
+    if (i != n)
+      luaL_addlstring(&b, sep, lsep);
+  }
+  luaL_pushresult(&b);
+  return 1;
+}
+
+
+
+/*
+** {======================================================
+** Quicksort
+** (based on `Algorithms in MODULA-3', Robert Sedgewick;
+**  Addison-Wesley, 1993.)
+*/
+
+
+static void set2 (lua_State *L, int i, int j) {
+  lua_rawseti(L, 1, i);
+  lua_rawseti(L, 1, j);
+}
+
+static int sort_comp (lua_State *L, int a, int b) {
+  if (!lua_isnil(L, 2)) {  /* function? */
+    int res;
+    lua_pushvalue(L, 2);
+    lua_pushvalue(L, a-1);  /* -1 to compensate function */
+    lua_pushvalue(L, b-2);  /* -2 to compensate function and `a' */
+    lua_call(L, 2, 1);
+    res = lua_toboolean(L, -1);
+    lua_pop(L, 1);
+    return res;
+  }
+  else  /* a < b? */
+    return lua_lessthan(L, a, b);
+}
+
+static void auxsort (lua_State *L, int l, int u) {
+  while (l < u) {  /* for tail recursion */
+    int i, j;
+    /* sort elements a[l], a[(l+u)/2] and a[u] */
+    lua_rawgeti(L, 1, l);
+    lua_rawgeti(L, 1, u);
+    if (sort_comp(L, -1, -2))  /* a[u] < a[l]? */
+      set2(L, l, u);  /* swap a[l] - a[u] */
+    else
+      lua_pop(L, 2);
+    if (u-l == 1) break;  /* only 2 elements */
+    i = (l+u)/2;
+    lua_rawgeti(L, 1, i);
+    lua_rawgeti(L, 1, l);
+    if (sort_comp(L, -2, -1))  /* a[i]<a[l]? */
+      set2(L, i, l);
+    else {
+      lua_pop(L, 1);  /* remove a[l] */
+      lua_rawgeti(L, 1, u);
+      if (sort_comp(L, -1, -2))  /* a[u]<a[i]? */
+        set2(L, i, u);
+      else
+        lua_pop(L, 2);
+    }
+    if (u-l == 2) break;  /* only 3 elements */
+    lua_rawgeti(L, 1, i);  /* Pivot */
+    lua_pushvalue(L, -1);
+    lua_rawgeti(L, 1, u-1);
+    set2(L, i, u-1);
+    /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
+    i = l; j = u-1;
+    for (;;) {  /* invariant: a[l..i] <= P <= a[j..u] */
+      /* repeat ++i until a[i] >= P */
+      while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
+        if (i>u) luaL_error(L, "invalid order function for sorting");
+        lua_pop(L, 1);  /* remove a[i] */
+      }
+      /* repeat --j until a[j] <= P */
+      while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
+        if (j<l) luaL_error(L, "invalid order function for sorting");
+        lua_pop(L, 1);  /* remove a[j] */
+      }
+      if (j<i) {
+        lua_pop(L, 3);  /* pop pivot, a[i], a[j] */
+        break;
+      }
+      set2(L, i, j);
+    }
+    lua_rawgeti(L, 1, u-1);
+    lua_rawgeti(L, 1, i);
+    set2(L, u-1, i);  /* swap pivot (a[u-1]) with a[i] */
+    /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
+    /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
+    if (i-l < u-i) {
+      j=l; i=i-1; l=i+2;
+    }
+    else {
+      j=i+1; i=u; u=j-2;
+    }
+    auxsort(L, j, i);  /* call recursively the smaller one */
+  }  /* repeat the routine for the larger one */
+}
+
+static int luaB_sort (lua_State *L) {
+  int n = aux_getn(L, 1);
+  luaL_checkstack(L, 40, "");  /* assume array is smaller than 2^40 */
+  if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
+    luaL_checktype(L, 2, LUA_TFUNCTION);
+  lua_settop(L, 2);  /* make sure there is two arguments */
+  auxsort(L, 1, n);
+  return 0;
+}
+
+/* }====================================================== */
+
+
+static const luaL_reg tab_funcs[] = {
+  {"concat", str_concat},
+  {"foreach", luaB_foreach},
+  {"foreachi", luaB_foreachi},
+  {"getn", luaB_getn},
+  {"setn", luaB_setn},
+  {"sort", luaB_sort},
+  {"insert", luaB_tinsert},
+  {"remove", luaB_tremove},
+  {NULL, NULL}
+};
+
+
+LUALIB_API int luaopen_table (lua_State *L) {
+  luaL_openlib(L, LUA_TABLIBNAME, tab_funcs, 0);
+  return 1;
+}
+
diff --git a/src/llex.c b/src/llex.c
index 4f511ab9..045e9994 100644
--- a/src/llex.c
+++ b/src/llex.c
@@ -1,24 +1,23 @@
 /*
-** $Id: llex.c,v 1.72 2000/10/20 16:39:03 roberto Exp $
+** $Id: llex.c,v 1.119 2003/03/24 12:39:34 roberto Exp $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
 
 
 #include <ctype.h>
-#include <stdio.h>
 #include <string.h>
 
+#define llex_c
+
 #include "lua.h"
 
+#include "ldo.h"
 #include "llex.h"
-#include "lmem.h"
 #include "lobject.h"
 #include "lparser.h"
 #include "lstate.h"
 #include "lstring.h"
-#include "ltable.h"
-#include "luadebug.h"
 #include "lzio.h"
 
 
@@ -29,16 +28,22 @@
 
 /* ORDER RESERVED */
 static const char *const token2string [] = {
-    "and", "break", "do", "else", "elseif", "end", "for",
-    "function", "if", "local", "nil", "not", "or", "repeat", "return", "then",
-    "until", "while", "", "..", "...", "==", ">=", "<=", "~=", "", "", "<eof>"};
+    "and", "break", "do", "else", "elseif",
+    "end", "false", "for", "function", "if",
+    "in", "local", "nil", "not", "or", "repeat",
+    "return", "then", "true", "until", "while", "*name",
+    "..", "...", "==", ">=", "<=", "~=",
+    "*number", "*string", "<eof>"
+};
 
 
 void luaX_init (lua_State *L) {
   int i;
   for (i=0; i<NUM_RESERVED; i++) {
     TString *ts = luaS_new(L, token2string[i]);
-    ts->marked = (unsigned char)(RESERVEDMARK+i);  /* reserved word */
+    luaS_fix(ts);  /* reserved words are never collected */
+    lua_assert(strlen(token2string[i])+1 <= TOKEN_LEN);
+    ts->tsv.reserved = cast(lu_byte, i+1);  /* reserved word */
   }
 }
 
@@ -48,50 +53,64 @@ void luaX_init (lua_State *L) {
 
 void luaX_checklimit (LexState *ls, int val, int limit, const char *msg) {
   if (val > limit) {
-    char buff[100];
-    sprintf(buff, "too many %.50s (limit=%d)", msg, limit);
-    luaX_error(ls, buff, ls->t.token);
+    msg = luaO_pushfstring(ls->L, "too many %s (limit=%d)", msg, limit);
+    luaX_syntaxerror(ls, msg);
   }
 }
 
 
-void luaX_syntaxerror (LexState *ls, const char *s, const char *token) {
+void luaX_errorline (LexState *ls, const char *s, const char *token, int line) {
+  lua_State *L = ls->L;
   char buff[MAXSRC];
-  luaO_chunkid(buff, ls->source->str, sizeof(buff));
-  luaO_verror(ls->L, "%.99s;\n  last token read: `%.30s' at line %d in %.80s",
-              s, token, ls->linenumber, buff);
+  luaO_chunkid(buff, getstr(ls->source), MAXSRC);
+  luaO_pushfstring(L, "%s:%d: %s near `%s'", buff, line, s, token); 
+  luaD_throw(L, LUA_ERRSYNTAX);
 }
 
 
-void luaX_error (LexState *ls, const char *s, int token) {
-  char buff[TOKEN_LEN];
-  luaX_token2str(token, buff);
-  if (buff[0] == '\0')
-    luaX_syntaxerror(ls, s, ls->L->Mbuffer);
-  else
-    luaX_syntaxerror(ls, s, buff);
+static void luaX_error (LexState *ls, const char *s, const char *token) {
+  luaX_errorline(ls, s, token, ls->linenumber);
+}
+
+
+void luaX_syntaxerror (LexState *ls, const char *msg) {
+  const char *lasttoken;
+  switch (ls->t.token) {
+    case TK_NAME:
+      lasttoken = getstr(ls->t.seminfo.ts);
+      break;
+    case TK_STRING:
+    case TK_NUMBER:
+      lasttoken = luaZ_buffer(ls->buff);
+      break;
+    default:
+      lasttoken = luaX_token2str(ls, ls->t.token);
+      break;
+  }
+  luaX_error(ls, msg, lasttoken);
 }
 
 
-void luaX_token2str (int token, char *s) {
-  if (token < 256) {
-    s[0] = (char)token;
-    s[1] = '\0';
+const char *luaX_token2str (LexState *ls, int token) {
+  if (token < FIRST_RESERVED) {
+    lua_assert(token == (unsigned char)token);
+    return luaO_pushfstring(ls->L, "%c", token);
   }
   else
-    strcpy(s, token2string[token-FIRST_RESERVED]);
+    return token2string[token-FIRST_RESERVED];
 }
 
 
-static void luaX_invalidchar (LexState *ls, int c) {
-  char buff[8];
-  sprintf(buff, "0x%02X", c);
-  luaX_syntaxerror(ls, "invalid control char", buff);
+static void luaX_lexerror (LexState *ls, const char *s, int token) {
+  if (token == TK_EOS)
+    luaX_error(ls, s, luaX_token2str(ls, token));
+  else
+    luaX_error(ls, s, luaZ_buffer(ls->buff));
 }
 
 
 static void inclinenumber (LexState *LS) {
-  next(LS);  /* skip '\n' */
+  next(LS);  /* skip `\n' */
   ++LS->linenumber;
   luaX_checklimit(LS, LS->linenumber, MAX_INT, "lines in a chunk");
 }
@@ -122,159 +141,173 @@ void luaX_setinput (lua_State *L, LexState *LS, ZIO *z, TString *source) {
 */
 
 
-/* use Mbuffer to store names, literal strings and numbers */
+/* use buffer to store names, literal strings and numbers */
+
+/* extra space to allocate when growing buffer */
+#define EXTRABUFF	32
+
+/* maximum number of chars that can be read without checking buffer size */
+#define MAXNOCHECK	5
 
-#define EXTRABUFF	128
-#define checkbuffer(L, n, len)	if ((len)+(n) > L->Mbuffsize) \
-                                  luaO_openspace(L, (len)+(n)+EXTRABUFF)
+#define checkbuffer(LS, len)	\
+    if (((len)+MAXNOCHECK)*sizeof(char) > luaZ_sizebuffer((LS)->buff)) \
+      luaZ_openspace((LS)->L, (LS)->buff, (len)+EXTRABUFF)
 
-#define save(L, c, l)	(L->Mbuffer[l++] = (char)c)
-#define save_and_next(L, LS, l)  (save(L, LS->current, l), next(LS))
+#define save(LS, c, l) \
+	(luaZ_buffer((LS)->buff)[l++] = cast(char, c))
+#define save_and_next(LS, l)  (save(LS, LS->current, l), next(LS))
 
 
-static const char *readname (LexState *LS) {
-  lua_State *L = LS->L;
+static size_t readname (LexState *LS) {
   size_t l = 0;
-  checkbuffer(L, 10, l);
+  checkbuffer(LS, l);
   do {
-    checkbuffer(L, 10, l);
-    save_and_next(L, LS, l);
+    checkbuffer(LS, l);
+    save_and_next(LS, l);
   } while (isalnum(LS->current) || LS->current == '_');
-  save(L, '\0', l);
-  return L->Mbuffer;
+  save(LS, '\0', l);
+  return l-1;
 }
 
 
 /* LUA_NUMBER */
-static void read_number (LexState *LS, int comma, SemInfo *seminfo) {
-  lua_State *L = LS->L;
+static void read_numeral (LexState *LS, int comma, SemInfo *seminfo) {
   size_t l = 0;
-  checkbuffer(L, 10, l);
-  if (comma) save(L, '.', l);
+  checkbuffer(LS, l);
+  if (comma) save(LS, '.', l);
   while (isdigit(LS->current)) {
-    checkbuffer(L, 10, l);
-    save_and_next(L, LS, l);
+    checkbuffer(LS, l);
+    save_and_next(LS, l);
   }
   if (LS->current == '.') {
-    save_and_next(L, LS, l);
+    save_and_next(LS, l);
     if (LS->current == '.') {
-      save_and_next(L, LS, l);
-      save(L, '\0', l);
-      luaX_error(LS, "ambiguous syntax"
-           " (decimal point x string concatenation)", TK_NUMBER);
+      save_and_next(LS, l);
+      save(LS, '\0', l);
+      luaX_lexerror(LS,
+                 "ambiguous syntax (decimal point x string concatenation)",
+                 TK_NUMBER);
     }
   }
   while (isdigit(LS->current)) {
-    checkbuffer(L, 10, l);
-    save_and_next(L, LS, l);
+    checkbuffer(LS, l);
+    save_and_next(LS, l);
   }
   if (LS->current == 'e' || LS->current == 'E') {
-    save_and_next(L, LS, l);  /* read 'E' */
+    save_and_next(LS, l);  /* read `E' */
     if (LS->current == '+' || LS->current == '-')
-      save_and_next(L, LS, l);  /* optional exponent sign */
+      save_and_next(LS, l);  /* optional exponent sign */
     while (isdigit(LS->current)) {
-      checkbuffer(L, 10, l);
-      save_and_next(L, LS, l);
+      checkbuffer(LS, l);
+      save_and_next(LS, l);
     }
   }
-  save(L, '\0', l);
-  if (!luaO_str2d(L->Mbuffer, &seminfo->r))
-    luaX_error(LS, "malformed number", TK_NUMBER);
+  save(LS, '\0', l);
+  if (!luaO_str2d(luaZ_buffer(LS->buff), &seminfo->r))
+    luaX_lexerror(LS, "malformed number", TK_NUMBER);
 }
 
 
 static void read_long_string (LexState *LS, SemInfo *seminfo) {
-  lua_State *L = LS->L;
   int cont = 0;
   size_t l = 0;
-  checkbuffer(L, 10, l);
-  save(L, '[', l);  /* save first '[' */
-  save_and_next(L, LS, l);  /* pass the second '[' */
+  checkbuffer(LS, l);
+  save(LS, '[', l);  /* save first `[' */
+  save_and_next(LS, l);  /* pass the second `[' */
+  if (LS->current == '\n')  /* string starts with a newline? */
+    inclinenumber(LS);  /* skip it */
   for (;;) {
-    checkbuffer(L, 10, l);
+    checkbuffer(LS, l);
     switch (LS->current) {
       case EOZ:
-        save(L, '\0', l);
-        luaX_error(LS, "unfinished long string", TK_STRING);
+        save(LS, '\0', l);
+        luaX_lexerror(LS, (seminfo) ? "unfinished long string" :
+                                   "unfinished long comment", TK_EOS);
         break;  /* to avoid warnings */
       case '[':
-        save_and_next(L, LS, l);
+        save_and_next(LS, l);
         if (LS->current == '[') {
           cont++;
-          save_and_next(L, LS, l);
+          save_and_next(LS, l);
         }
         continue;
       case ']':
-        save_and_next(L, LS, l);
+        save_and_next(LS, l);
         if (LS->current == ']') {
           if (cont == 0) goto endloop;
           cont--;
-          save_and_next(L, LS, l);
+          save_and_next(LS, l);
         }
         continue;
       case '\n':
-        save(L, '\n', l);
+        save(LS, '\n', l);
         inclinenumber(LS);
+        if (!seminfo) l = 0;  /* reset buffer to avoid wasting space */
         continue;
       default:
-        save_and_next(L, LS, l);
+        save_and_next(LS, l);
     }
   } endloop:
-  save_and_next(L, LS, l);  /* skip the second ']' */
-  save(L, '\0', l);
-  seminfo->ts = luaS_newlstr(L, L->Mbuffer+2, l-5);
+  save_and_next(LS, l);  /* skip the second `]' */
+  save(LS, '\0', l);
+  if (seminfo)
+    seminfo->ts = luaS_newlstr(LS->L, luaZ_buffer(LS->buff) + 2, l - 5);
 }
 
 
 static void read_string (LexState *LS, int del, SemInfo *seminfo) {
-  lua_State *L = LS->L;
   size_t l = 0;
-  checkbuffer(L, 10, l);
-  save_and_next(L, LS, l);
+  checkbuffer(LS, l);
+  save_and_next(LS, l);
   while (LS->current != del) {
-    checkbuffer(L, 10, l);
+    checkbuffer(LS, l);
     switch (LS->current) {
-      case EOZ:  case '\n':
-        save(L, '\0', l);
-        luaX_error(LS, "unfinished string", TK_STRING);
+      case EOZ:
+        save(LS, '\0', l);
+        luaX_lexerror(LS, "unfinished string", TK_EOS);
+        break;  /* to avoid warnings */
+      case '\n':
+        save(LS, '\0', l);
+        luaX_lexerror(LS, "unfinished string", TK_STRING);
         break;  /* to avoid warnings */
       case '\\':
-        next(LS);  /* do not save the '\' */
+        next(LS);  /* do not save the `\' */
         switch (LS->current) {
-          case 'a': save(L, '\a', l); next(LS); break;
-          case 'b': save(L, '\b', l); next(LS); break;
-          case 'f': save(L, '\f', l); next(LS); break;
-          case 'n': save(L, '\n', l); next(LS); break;
-          case 'r': save(L, '\r', l); next(LS); break;
-          case 't': save(L, '\t', l); next(LS); break;
-          case 'v': save(L, '\v', l); next(LS); break;
-          case '\n': save(L, '\n', l); inclinenumber(LS); break;
-          case '0': case '1': case '2': case '3': case '4':
-          case '5': case '6': case '7': case '8': case '9': {
-            int c = 0;
-            int i = 0;
-            do {
-              c = 10*c + (LS->current-'0');
-              next(LS);
-            } while (++i<3 && isdigit(LS->current));
-            if (c != (unsigned char)c) {
-              save(L, '\0', l);
-              luaX_error(LS, "escape sequence too large", TK_STRING);
+          case 'a': save(LS, '\a', l); next(LS); break;
+          case 'b': save(LS, '\b', l); next(LS); break;
+          case 'f': save(LS, '\f', l); next(LS); break;
+          case 'n': save(LS, '\n', l); next(LS); break;
+          case 'r': save(LS, '\r', l); next(LS); break;
+          case 't': save(LS, '\t', l); next(LS); break;
+          case 'v': save(LS, '\v', l); next(LS); break;
+          case '\n': save(LS, '\n', l); inclinenumber(LS); break;
+          case EOZ: break;  /* will raise an error next loop */
+          default: {
+            if (!isdigit(LS->current))
+              save_and_next(LS, l);  /* handles \\, \", \', and \? */
+            else {  /* \xxx */
+              int c = 0;
+              int i = 0;
+              do {
+                c = 10*c + (LS->current-'0');
+                next(LS);
+              } while (++i<3 && isdigit(LS->current));
+              if (c > UCHAR_MAX) {
+                save(LS, '\0', l);
+                luaX_lexerror(LS, "escape sequence too large", TK_STRING);
+              }
+              save(LS, c, l);
             }
-            save(L, c, l);
-            break;
           }
-          default:  /* handles \\, \", \', and \? */
-            save_and_next(L, LS, l);
         }
         break;
       default:
-        save_and_next(L, LS, l);
+        save_and_next(LS, l);
     }
   }
-  save_and_next(L, LS, l);  /* skip delimiter */
-  save(L, '\0', l);
-  seminfo->ts = luaS_newlstr(L, L->Mbuffer+1, l-3);
+  save_and_next(LS, l);  /* skip delimiter */
+  save(LS, '\0', l);
+  seminfo->ts = luaS_newlstr(LS->L, luaZ_buffer(LS->buff) + 1, l - 3);
 }
 
 
@@ -282,58 +315,56 @@ int luaX_lex (LexState *LS, SemInfo *seminfo) {
   for (;;) {
     switch (LS->current) {
 
-      case ' ': case '\t': case '\r':  /* `\r' to avoid problems with DOS */
-        next(LS);
-        continue;
-
-      case '\n':
+      case '\n': {
         inclinenumber(LS);
         continue;
-
-      case '$':
-        luaX_error(LS, "unexpected `$' (pragmas are no longer supported)", '$');
-        break;
-
-      case '-':
+      }
+      case '-': {
         next(LS);
         if (LS->current != '-') return '-';
-        do { next(LS); } while (LS->current != '\n' && LS->current != EOZ);
+        /* else is a comment */
+        next(LS);
+        if (LS->current == '[' && (next(LS), LS->current == '['))
+          read_long_string(LS, NULL);  /* long comment */
+        else  /* short comment */
+          while (LS->current != '\n' && LS->current != EOZ)
+            next(LS);
         continue;
-
-      case '[':
+      }
+      case '[': {
         next(LS);
         if (LS->current != '[') return '[';
         else {
           read_long_string(LS, seminfo);
           return TK_STRING;
         }
-
-      case '=':
+      }
+      case '=': {
         next(LS);
         if (LS->current != '=') return '=';
         else { next(LS); return TK_EQ; }
-
-      case '<':
+      }
+      case '<': {
         next(LS);
         if (LS->current != '=') return '<';
         else { next(LS); return TK_LE; }
-
-      case '>':
+      }
+      case '>': {
         next(LS);
         if (LS->current != '=') return '>';
         else { next(LS); return TK_GE; }
-
-      case '~':
+      }
+      case '~': {
         next(LS);
         if (LS->current != '=') return '~';
         else { next(LS); return TK_NE; }
-
+      }
       case '"':
-      case '\'':
+      case '\'': {
         read_string(LS, LS->current, seminfo);
         return TK_STRING;
-
-      case '.':
+      }
+      case '.': {
         next(LS);
         if (LS->current == '.') {
           next(LS);
@@ -345,36 +376,42 @@ int luaX_lex (LexState *LS, SemInfo *seminfo) {
         }
         else if (!isdigit(LS->current)) return '.';
         else {
-          read_number(LS, 1, seminfo);
+          read_numeral(LS, 1, seminfo);
           return TK_NUMBER;
         }
-
-      case '0': case '1': case '2': case '3': case '4':
-      case '5': case '6': case '7': case '8': case '9':
-        read_number(LS, 0, seminfo);
-        return TK_NUMBER;
-
-      case EOZ:
+      }
+      case EOZ: {
         return TK_EOS;
-
-      case '_': goto tname;
-
-      default:
-        if (!isalpha(LS->current)) {
-          int c = LS->current;
-          if (iscntrl(c))
-            luaX_invalidchar(LS, c);
+      }
+      default: {
+        if (isspace(LS->current)) {
           next(LS);
-          return c;
+          continue;
+        }
+        else if (isdigit(LS->current)) {
+          read_numeral(LS, 0, seminfo);
+          return TK_NUMBER;
         }
-        tname: {  /* identifier or reserved word */
-          TString *ts = luaS_new(LS->L, readname(LS));
-          if (ts->marked >= RESERVEDMARK)  /* reserved word? */
-            return ts->marked-RESERVEDMARK+FIRST_RESERVED;
+        else if (isalpha(LS->current) || LS->current == '_') {
+          /* identifier or reserved word */
+          size_t l = readname(LS);
+          TString *ts = luaS_newlstr(LS->L, luaZ_buffer(LS->buff), l);
+          if (ts->tsv.reserved > 0)  /* reserved word? */
+            return ts->tsv.reserved - 1 + FIRST_RESERVED;
           seminfo->ts = ts;
           return TK_NAME;
         }
+        else {
+          int c = LS->current;
+          if (iscntrl(c))
+            luaX_error(LS, "invalid control char",
+                           luaO_pushfstring(LS->L, "char(%d)", c));
+          next(LS);
+          return c;  /* single-char tokens (+ - / ...) */
+        }
+      }
     }
   }
 }
 
+#undef next
diff --git a/src/llex.h b/src/llex.h
index 3b379960..740e3f6b 100644
--- a/src/llex.h
+++ b/src/llex.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.h,v 1.31 2000/09/27 17:41:58 roberto Exp $
+** $Id: llex.h,v 1.47 2003/02/28 17:19:47 roberto Exp $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -13,8 +13,8 @@
 
 #define FIRST_RESERVED	257
 
-/* maximum length of a reserved word (+1 for final 0) */
-#define TOKEN_LEN	15
+/* maximum length of a reserved word */
+#define TOKEN_LEN	(sizeof("function")/sizeof(char))
 
 
 /*
@@ -24,19 +24,20 @@
 enum RESERVED {
   /* terminal symbols denoted by reserved words */
   TK_AND = FIRST_RESERVED, TK_BREAK,
-  TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FOR, TK_FUNCTION, TK_IF, TK_LOCAL,
-  TK_NIL, TK_NOT, TK_OR, TK_REPEAT, TK_RETURN, TK_THEN, TK_UNTIL, TK_WHILE,
+  TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FALSE, TK_FOR, TK_FUNCTION,
+  TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT,
+  TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE,
   /* other terminal symbols */
   TK_NAME, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE, TK_NUMBER,
   TK_STRING, TK_EOS
 };
 
 /* number of reserved words */
-#define NUM_RESERVED	((int)(TK_WHILE-FIRST_RESERVED+1))
+#define NUM_RESERVED	(cast(int, TK_WHILE-FIRST_RESERVED+1))
 
 
 typedef union {
-  Number r;
+  lua_Number r;
   TString *ts;
 } SemInfo;  /* semantics information */
 
@@ -48,15 +49,17 @@ typedef struct Token {
 
 
 typedef struct LexState {
-  int current;  /* current character */
+  int current;  /* current character (charint) */
+  int linenumber;  /* input line counter */
+  int lastline;  /* line of last token `consumed' */
   Token t;  /* current token */
   Token lookahead;  /* look ahead token */
   struct FuncState *fs;  /* `FuncState' is private to the parser */
   struct lua_State *L;
-  struct zio *z;  /* input stream */
-  int linenumber;  /* input line counter */
-  int lastline;  /* line of last token `consumed' */
+  ZIO *z;  /* input stream */
+  Mbuffer *buff;  /* buffer for tokens */
   TString *source;  /* current source name */
+  int nestlevel;  /* level of nested non-terminals */
 } LexState;
 
 
@@ -64,9 +67,9 @@ void luaX_init (lua_State *L);
 void luaX_setinput (lua_State *L, LexState *LS, ZIO *z, TString *source);
 int luaX_lex (LexState *LS, SemInfo *seminfo);
 void luaX_checklimit (LexState *ls, int val, int limit, const char *msg);
-void luaX_syntaxerror (LexState *ls, const char *s, const char *token);
-void luaX_error (LexState *ls, const char *s, int token);
-void luaX_token2str (int token, char *s);
+void luaX_syntaxerror (LexState *ls, const char *s);
+void luaX_errorline (LexState *ls, const char *s, const char *token, int line);
+const char *luaX_token2str (LexState *ls, int token);
 
 
 #endif
diff --git a/src/llimits.h b/src/llimits.h
index b3f5de47..343c9226 100644
--- a/src/llimits.h
+++ b/src/llimits.h
@@ -1,6 +1,6 @@
 /*
-** $Id: llimits.h,v 1.19 2000/10/26 12:47:05 roberto Exp $
-** Limits, basic types, and some other "installation-dependent" definitions
+** $Id: llimits.h,v 1.52 2003/02/20 19:33:23 roberto Exp $
+** Limits, basic types, and some other `installation-dependent' definitions
 ** See Copyright Notice in lua.h
 */
 
@@ -12,6 +12,8 @@
 #include <stddef.h>
 
 
+#include "lua.h"
+
 
 /*
 ** try to find number of bits in an integer
@@ -32,25 +34,29 @@
 
 
 /*
-** Define the type `number' of Lua
-** GREP LUA_NUMBER to change that
+** the following types define integer types for values that may not
+** fit in a `small int' (16 bits), but may waste space in a
+** `large long' (64 bits). The current definitions should work in
+** any machine, but may not be optimal.
 */
-#ifndef LUA_NUM_TYPE
-#define LUA_NUM_TYPE double
-#endif
 
-typedef LUA_NUM_TYPE Number;
+/* an unsigned integer to hold hash values */
+typedef unsigned int lu_hash;
+/* its signed equivalent */
+typedef int ls_hash;
 
-/* function to convert a Number to a string */
-#define NUMBER_FMT	"%.16g"		/* LUA_NUMBER */
-#define lua_number2str(s,n)	sprintf((s), NUMBER_FMT, (n))
+/* an unsigned integer big enough to count the total memory used by Lua; */
+/* it should be at least as large as size_t */
+typedef unsigned long lu_mem;
 
-/* function to convert a string to a Number */
-#define lua_str2number(s,p)	strtod((s), (p))
+#define MAX_LUMEM	ULONG_MAX
 
 
+/* an integer big enough to count the number of strings in use */
+typedef long ls_nstr;
 
-typedef unsigned long lint32;  /* unsigned int with at least 32 bits */
+/* chars used as small naturals (so that `char' is reserved for characters) */
+typedef unsigned char lu_byte;
 
 
 #define MAX_SIZET	((size_t)(~(size_t)0)-2)
@@ -59,117 +65,93 @@ typedef unsigned long lint32;  /* unsigned int with at least 32 bits */
 #define MAX_INT (INT_MAX-2)  /* maximum value of an int (-2 for safety) */
 
 /*
-** conversion of pointer to int (for hashing only)
-** (the shift removes bits that are usually 0 because of alignment)
+** conversion of pointer to integer
+** this is for hashing only; there is no problem if the integer
+** cannot hold the whole pointer value
 */
-#define IntPoint(p)  (((unsigned long)(p)) >> 3)
+#define IntPoint(p)  ((lu_hash)(p))
+
 
 
+/* type to ensure maximum alignment */
+#ifndef LUSER_ALIGNMENT_T
+typedef union { double u; void *s; long l; } L_Umaxalign;
+#else
+typedef LUSER_ALIGNMENT_T L_Umaxalign;
+#endif
 
-#define MINPOWER2       4       /* minimum size for "growing" vectors */
 
+/* result of `usual argument conversion' over lua_Number */
+#ifndef LUA_UACNUMBER
+typedef double l_uacNumber;
+#else
+typedef LUA_UACNUMBER l_uacNumber;
+#endif
 
 
-#ifndef DEFAULT_STACK_SIZE
-#define DEFAULT_STACK_SIZE      1024
+#ifndef lua_assert
+#define lua_assert(c)		/* empty */
 #endif
 
 
+#ifndef check_exp
+#define check_exp(c,e)	(e)
+#endif
 
-/* type to ensure maximum alignment */
-union L_Umaxalign { double d; char *s; long l; };
+
+#ifndef UNUSED
+#define UNUSED(x)	((void)(x))	/* to avoid warnings */
+#endif
+
+
+#ifndef cast
+#define cast(t, exp)	((t)(exp))
+#endif
 
 
 
 /*
 ** type for virtual-machine instructions
 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
-** For a very small machine, you may change that to 2 bytes (and adjust
-** the following limits accordingly)
 */
 typedef unsigned long Instruction;
 
 
-/*
-** size and position of opcode arguments.
-** For an instruction with 2 bytes, size is 16, and size_b can be 5
-** (accordingly, size_u will be 10, and size_a will be 5)
-*/
-#define SIZE_INSTRUCTION        32
-#define SIZE_B          9
-
-#define SIZE_OP         6
-#define SIZE_U          (SIZE_INSTRUCTION-SIZE_OP)
-#define POS_U           SIZE_OP
-#define POS_B           SIZE_OP
-#define SIZE_A          (SIZE_INSTRUCTION-(SIZE_OP+SIZE_B))
-#define POS_A           (SIZE_OP+SIZE_B)
+/* maximum depth for calls (unsigned short) */
+#ifndef LUA_MAXCALLS
+#define LUA_MAXCALLS        4096
+#endif
 
 
 /*
-** limits for opcode arguments.
-** we use (signed) int to manipulate most arguments,
-** so they must fit in BITS_INT-1 bits (-1 for sign)
+** maximum depth for C calls (unsigned short): Not too big, or may
+** overflow the C stack...
 */
-#if SIZE_U < BITS_INT-1
-#define MAXARG_U        ((1<<SIZE_U)-1)
-#define MAXARG_S        (MAXARG_U>>1)		/* `S' is signed */
-#else
-#define MAXARG_U        MAX_INT
-#define MAXARG_S        MAX_INT
-#endif
 
-#if SIZE_A < BITS_INT-1
-#define MAXARG_A        ((1<<SIZE_A)-1)
-#else
-#define MAXARG_A        MAX_INT
+#ifndef LUA_MAXCCALLS
+#define LUA_MAXCCALLS        200
 #endif
 
-#if SIZE_B < BITS_INT-1
-#define MAXARG_B        ((1<<SIZE_B)-1)
-#else
-#define MAXARG_B        MAX_INT
+
+/* maximum size for the C stack */
+#ifndef LUA_MAXCSTACK
+#define LUA_MAXCSTACK        2048
 #endif
 
 
-/* maximum stack size in a function */
-#ifndef MAXSTACK
+/* maximum stack for a Lua function */
 #define MAXSTACK	250
-#endif
-
-#if MAXSTACK > MAXARG_B
-#undef MAXSTACK
-#define MAXSTACK	MAXARG_B
-#endif
 
 
-/* maximum number of local variables */
-#ifndef MAXLOCALS
-#define MAXLOCALS 200           /* arbitrary limit (<MAXSTACK) */
-#endif
-#if MAXLOCALS>=MAXSTACK
-#undef MAXLOCALS
-#define MAXLOCALS	(MAXSTACK-1)
+/* maximum number of variables declared in a function */
+#ifndef MAXVARS
+#define MAXVARS 200           /* arbitrary limit (<MAXSTACK) */
 #endif
 
 
-/* maximum number of upvalues */
+/* maximum number of upvalues per function */
 #ifndef MAXUPVALUES
-#define MAXUPVALUES 32          /* arbitrary limit (<=MAXARG_B) */
-#endif
-#if MAXUPVALUES>MAXARG_B
-#undef MAXUPVALUES
-#define MAXUPVALUES	MAXARG_B
-#endif
-
-
-/* maximum number of variables in the left side of an assignment */
-#ifndef MAXVARSLH
-#define MAXVARSLH 100           /* arbitrary limit (<MULT_RET) */
-#endif
-#if MAXVARSLH>=MULT_RET
-#undef MAXVARSLH
-#define MAXVARSLH	(MULT_RET-1)
+#define MAXUPVALUES	32
 #endif
 
 
@@ -177,27 +159,26 @@ typedef unsigned long Instruction;
 #ifndef MAXPARAMS
 #define MAXPARAMS 100           /* arbitrary limit (<MAXLOCALS) */
 #endif
-#if MAXPARAMS>=MAXLOCALS
-#undef MAXPARAMS
-#define MAXPARAMS	(MAXLOCALS-1)
-#endif
 
 
-/* number of list items to accumulate before a SETLIST instruction */
-#define LFIELDS_PER_FLUSH	64
-#if LFIELDS_PER_FLUSH>(MAXSTACK/4)
-#undef LFIELDS_PER_FLUSH
-#define LFIELDS_PER_FLUSH	(MAXSTACK/4)
+/* minimum size for the string table (must be power of 2) */
+#ifndef MINSTRTABSIZE
+#define MINSTRTABSIZE	32
 #endif
 
-/* number of record items to accumulate before a SETMAP instruction */
-/* (each item counts 2 elements on the stack: an index and a value) */
-#define RFIELDS_PER_FLUSH	(LFIELDS_PER_FLUSH/2)
+
+/* minimum size for string buffer */
+#ifndef LUA_MINBUFFER
+#define LUA_MINBUFFER	32
+#endif
 
 
-/* maximum lookback to find a real constant (for code generation) */
-#ifndef LOOKBACKNUMS
-#define LOOKBACKNUMS    20      /* arbitrary constant */
+/*
+** maximum number of syntactical nested non-terminals: Not too big,
+** or may overflow the C stack...
+*/
+#ifndef LUA_MAXPARSERLEVEL
+#define LUA_MAXPARSERLEVEL	200
 #endif
 
 
diff --git a/src/lmem.c b/src/lmem.c
index 03a804c9..f977770a 100644
--- a/src/lmem.c
+++ b/src/lmem.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.39 2000/10/30 16:29:59 roberto Exp $
+** $Id: lmem.c,v 1.61 2002/12/04 17:38:31 roberto Exp $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -7,8 +7,11 @@
 
 #include <stdlib.h>
 
+#define lmem_c
+
 #include "lua.h"
 
+#include "ldebug.h"
 #include "ldo.h"
 #include "lmem.h"
 #include "lobject.h"
@@ -16,135 +19,73 @@
 
 
 
-
-#ifdef LUA_DEBUG
 /*
-** {======================================================================
-** Controlled version for realloc.
-** =======================================================================
+** definition for realloc function. It must assure that l_realloc(NULL,
+** 0, x) allocates a new block (ANSI C assures that). (`os' is the old
+** block size; some allocators may use that.)
 */
-
-
-#include <assert.h>
-#include <limits.h>
-#include <string.h>
-
-#define realloc(b, s)	debug_realloc(b, s)
-#define malloc(b)	debug_realloc(NULL, b)
-#define free(b)		debug_realloc(b, 0)
-
-
-/* ensures maximum alignment for HEADER */
-#define HEADER	(sizeof(union L_Umaxalign))
-
-#define MARKSIZE	16
-#define MARK		0x55  /* 01010101 (a nice pattern) */
-
-
-#define blocksize(b)	((unsigned long *)((char *)(b) - HEADER))
-
-unsigned long memdebug_numblocks = 0;
-unsigned long memdebug_total = 0;
-unsigned long memdebug_maxmem = 0;
-unsigned long memdebug_memlimit = LONG_MAX;
-
-
-static void *checkblock (void *block) {
-  unsigned long *b = blocksize(block);
-  unsigned long size = *b;
-  int i;
-  for (i=0;i<MARKSIZE;i++)
-    assert(*(((char *)b)+HEADER+size+i) == MARK+i);  /* corrupted block? */
-  memdebug_numblocks--;
-  memdebug_total -= size;
-  return b;
-}
-
-
-static void freeblock (void *block) {
-  if (block) {
-    size_t size = *blocksize(block);
-    block = checkblock(block);
-    memset(block, -1, size+HEADER+MARKSIZE);  /* erase block */
-    (free)(block);  /* free original block */
-  }
-}
-
-
-static void *debug_realloc (void *block, size_t size) {
-  if (size == 0) {
-    freeblock(block);
-    return NULL;
-  }
-  else if (memdebug_total+size > memdebug_memlimit)
-    return NULL;  /* to test memory allocation errors */
-  else {
-    size_t realsize = HEADER+size+MARKSIZE;
-    char *newblock = (char *)(malloc)(realsize);  /* alloc a new block */
-    int i;
-    if (realsize < size) return NULL;  /* overflow! */
-    if (newblock == NULL) return NULL;
-    if (block) {
-      size_t oldsize = *blocksize(block);
-      if (oldsize > size) oldsize = size;
-      memcpy(newblock+HEADER, block, oldsize);
-      freeblock(block);  /* erase (and check) old copy */
-    }
-    memdebug_total += size;
-    if (memdebug_total > memdebug_maxmem) memdebug_maxmem = memdebug_total;
-    memdebug_numblocks++;
-    *(unsigned long *)newblock = size;
-    for (i=0;i<MARKSIZE;i++)
-      *(newblock+HEADER+size+i) = (char)(MARK+i);
-    return newblock+HEADER;
-  }
-}
-
-
-/* }====================================================================== */
+#ifndef l_realloc
+#define l_realloc(b,os,s)	realloc(b,s)
 #endif
 
-
-
 /*
-** Real ISO (ANSI) systems do not need these tests;
-** but some systems (Sun OS) are not that ISO...
+** definition for free function. (`os' is the old block size; some
+** allocators may use that.)
 */
-#ifdef OLD_ANSI
-#define realloc(b,s)	((b) == NULL ? malloc(s) : (realloc)(b, s))
-#define free(b)		if (b) (free)(b)
+#ifndef l_free
+#define l_free(b,os)	free(b)
 #endif
 
 
-void *luaM_growaux (lua_State *L, void *block, size_t nelems,
-               int inc, size_t size, const char *errormsg, size_t limit) {
-  size_t newn = nelems+inc;
-  if (nelems >= limit-inc) lua_error(L, errormsg);
-  if ((newn ^ nelems) <= nelems ||  /* still the same power-of-2 limit? */
-       (nelems > 0 && newn < MINPOWER2))  /* or block already is MINPOWER2? */
-      return block;  /* do not need to reallocate */
-  else  /* it crossed a power-of-2 boundary; grow to next power */
-    return luaM_realloc(L, block, luaO_power2(newn)*size);
+#define MINSIZEARRAY	4
+
+
+void *luaM_growaux (lua_State *L, void *block, int *size, int size_elems,
+                    int limit, const char *errormsg) {
+  void *newblock;
+  int newsize = (*size)*2;
+  if (newsize < MINSIZEARRAY)
+    newsize = MINSIZEARRAY;  /* minimum size */
+  else if (*size >= limit/2) {  /* cannot double it? */
+    if (*size < limit - MINSIZEARRAY)  /* try something smaller... */
+      newsize = limit;  /* still have at least MINSIZEARRAY free places */
+    else luaG_runerror(L, errormsg);
+  }
+  newblock = luaM_realloc(L, block,
+                          cast(lu_mem, *size)*cast(lu_mem, size_elems),
+                          cast(lu_mem, newsize)*cast(lu_mem, size_elems));
+  *size = newsize;  /* update only when everything else is OK */
+  return newblock;
 }
 
 
 /*
 ** generic allocation routine.
 */
-void *luaM_realloc (lua_State *L, void *block, lint32 size) {
+void *luaM_realloc (lua_State *L, void *block, lu_mem oldsize, lu_mem size) {
+  lua_assert((oldsize == 0) == (block == NULL));
   if (size == 0) {
-    free(block);  /* block may be NULL; that is OK for free */
-    return NULL;
+    if (block != NULL) {
+      l_free(block, oldsize);
+      block = NULL;
+    }
+    else return NULL;  /* avoid `nblocks' computations when oldsize==size==0 */
   }
   else if (size >= MAX_SIZET)
-    lua_error(L, "memory allocation error: block too big");
-  block = realloc(block, size);
-  if (block == NULL) {
-    if (L)
-      luaD_breakrun(L, LUA_ERRMEM);  /* break run without error message */
-    else return NULL;  /* error before creating state! */
+    luaG_runerror(L, "memory allocation error: block too big");
+  else {
+    block = l_realloc(block, oldsize, size);
+    if (block == NULL) {
+      if (L)
+        luaD_throw(L, LUA_ERRMEM);
+      else return NULL;  /* error before creating state! */
+    }
+  }
+  if (L) {
+    lua_assert(G(L) != NULL && G(L)->nblocks > 0);
+    G(L)->nblocks -= oldsize;
+    G(L)->nblocks += size;
   }
   return block;
 }
 
-
diff --git a/src/lmem.h b/src/lmem.h
index 9e7c829d..1bb4fde0 100644
--- a/src/lmem.h
+++ b/src/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.16 2000/10/30 16:29:59 roberto Exp $
+** $Id: lmem.h,v 1.26 2002/05/01 20:40:42 roberto Exp $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -13,29 +13,31 @@
 #include "llimits.h"
 #include "lua.h"
 
-void *luaM_realloc (lua_State *L, void *oldblock, lint32 size);
-void *luaM_growaux (lua_State *L, void *block, size_t nelems,
-                    int inc, size_t size, const char *errormsg,
-                    size_t limit);
+#define MEMERRMSG	"not enough memory"
 
-#define luaM_free(L, b)		luaM_realloc(L, (b), 0)
-#define luaM_malloc(L, t)	luaM_realloc(L, NULL, (t))
-#define luaM_new(L, t)          ((t *)luaM_malloc(L, sizeof(t)))
-#define luaM_newvector(L, n,t)  ((t *)luaM_malloc(L, (n)*(lint32)sizeof(t)))
 
-#define luaM_growvector(L, v,nelems,inc,t,e,l) \
-          ((v)=(t *)luaM_growaux(L, v,nelems,inc,sizeof(t),e,l))
+void *luaM_realloc (lua_State *L, void *oldblock, lu_mem oldsize, lu_mem size);
 
-#define luaM_reallocvector(L, v,n,t) \
-	((v)=(t *)luaM_realloc(L, v,(n)*(lint32)sizeof(t)))
+void *luaM_growaux (lua_State *L, void *block, int *size, int size_elem,
+                    int limit, const char *errormsg);
 
+#define luaM_free(L, b, s)	luaM_realloc(L, (b), (s), 0)
+#define luaM_freelem(L, b)	luaM_realloc(L, (b), sizeof(*(b)), 0)
+#define luaM_freearray(L, b, n, t)	luaM_realloc(L, (b), \
+                                      cast(lu_mem, n)*cast(lu_mem, sizeof(t)), 0)
 
-#ifdef LUA_DEBUG
-extern unsigned long memdebug_numblocks;
-extern unsigned long memdebug_total;
-extern unsigned long memdebug_maxmem;
-extern unsigned long memdebug_memlimit;
-#endif
+#define luaM_malloc(L, t)	luaM_realloc(L, NULL, 0, (t))
+#define luaM_new(L, t)          cast(t *, luaM_malloc(L, sizeof(t)))
+#define luaM_newvector(L, n,t)  cast(t *, luaM_malloc(L, \
+                                         cast(lu_mem, n)*cast(lu_mem, sizeof(t))))
+
+#define luaM_growvector(L,v,nelems,size,t,limit,e) \
+          if (((nelems)+1) > (size)) \
+            ((v)=cast(t *, luaM_growaux(L,v,&(size),sizeof(t),limit,e)))
+
+#define luaM_reallocvector(L, v,oldn,n,t) \
+   ((v)=cast(t *, luaM_realloc(L, v,cast(lu_mem, oldn)*cast(lu_mem, sizeof(t)), \
+                                    cast(lu_mem, n)*cast(lu_mem, sizeof(t)))))
 
 
 #endif
diff --git a/src/lobject.c b/src/lobject.c
index e787fbe8..9522b6e8 100644
--- a/src/lobject.c
+++ b/src/lobject.c
@@ -1,92 +1,162 @@
 /*
-** $Id: lobject.c,v 1.55 2000/10/20 16:36:32 roberto Exp $
+** $Id: lobject.c,v 1.97 2003/04/03 13:35:34 roberto Exp $
 ** Some generic functions over Lua objects
 ** See Copyright Notice in lua.h
 */
 
 #include <ctype.h>
 #include <stdarg.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#define lobject_c
+
 #include "lua.h"
 
+#include "ldo.h"
 #include "lmem.h"
 #include "lobject.h"
 #include "lstate.h"
+#include "lstring.h"
+#include "lvm.h"
 
 
+/* function to convert a string to a lua_Number */
+#ifndef lua_str2number
+#define lua_str2number(s,p)     strtod((s), (p))
+#endif
 
-const TObject luaO_nilobject = {LUA_TNIL, {NULL}};
-
-
-const char *const luaO_typenames[] = {
-  "userdata", "nil", "number", "string", "table", "function"
-};
 
+const TObject luaO_nilobject = {LUA_TNIL, {NULL}};
 
 
 /*
-** returns smaller power of 2 larger than `n' (minimum is MINPOWER2) 
+** converts an integer to a "floating point byte", represented as
+** (mmmmmxxx), where the real value is (xxx) * 2^(mmmmm)
 */
-lint32 luaO_power2 (lint32 n) {
-  lint32 p = MINPOWER2;
-  while (p<=n) p<<=1;
-  return p;
+int luaO_int2fb (unsigned int x) {
+  int m = 0;  /* mantissa */
+  while (x >= (1<<3)) {
+    x = (x+1) >> 1;
+    m++;
+  }
+  return (m << 3) | cast(int, x);
 }
 
 
-int luaO_equalObj (const TObject *t1, const TObject *t2) {
-  if (ttype(t1) != ttype(t2)) return 0;
-  switch (ttype(t1)) {
-    case LUA_TNUMBER:
-      return nvalue(t1) == nvalue(t2);
-    case LUA_TSTRING: case LUA_TUSERDATA:
-      return tsvalue(t1) == tsvalue(t2);
-    case LUA_TTABLE: 
-      return hvalue(t1) == hvalue(t2);
-    case LUA_TFUNCTION:
-      return clvalue(t1) == clvalue(t2);
-    default:
-      LUA_ASSERT(ttype(t1) == LUA_TNIL, "invalid type");
-      return 1; /* LUA_TNIL */
+int luaO_log2 (unsigned int x) {
+  static const lu_byte log_8[255] = {
+    0,
+    1,1,
+    2,2,2,2,
+    3,3,3,3,3,3,3,3,
+    4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
+    5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+  };
+  if (x >= 0x00010000) {
+    if (x >= 0x01000000) return log_8[((x>>24) & 0xff) - 1]+24;
+    else return log_8[((x>>16) & 0xff) - 1]+16;
+  }
+  else {
+    if (x >= 0x00000100) return log_8[((x>>8) & 0xff) - 1]+8;
+    else if (x) return log_8[(x & 0xff) - 1];
+    return -1;  /* special `log' for 0 */
   }
 }
 
 
-char *luaO_openspace (lua_State *L, size_t n) {
-  if (n > L->Mbuffsize) {
-    luaM_reallocvector(L, L->Mbuffer, n, char);
-    L->nblocks += (n - L->Mbuffsize)*sizeof(char);
-    L->Mbuffsize = n;
+int luaO_rawequalObj (const TObject *t1, const TObject *t2) {
+  if (ttype(t1) != ttype(t2)) return 0;
+  else switch (ttype(t1)) {
+    case LUA_TNIL:
+      return 1;
+    case LUA_TNUMBER:
+      return nvalue(t1) == nvalue(t2);
+    case LUA_TBOOLEAN:
+      return bvalue(t1) == bvalue(t2);  /* boolean true must be 1 !! */
+    case LUA_TLIGHTUSERDATA:
+      return pvalue(t1) == pvalue(t2);
+    default:
+      lua_assert(iscollectable(t1));
+      return gcvalue(t1) == gcvalue(t2);
   }
-  return L->Mbuffer;
 }
 
 
-int luaO_str2d (const char *s, Number *result) {  /* LUA_NUMBER */
+int luaO_str2d (const char *s, lua_Number *result) {
   char *endptr;
-  Number res = lua_str2number(s, &endptr);
+  lua_Number res = lua_str2number(s, &endptr);
   if (endptr == s) return 0;  /* no conversion */
-  while (isspace((unsigned char)*endptr)) endptr++;
+  while (isspace((unsigned char)(*endptr))) endptr++;
   if (*endptr != '\0') return 0;  /* invalid trailing characters? */
   *result = res;
   return 1;
 }
 
 
-/* maximum length of a string format for `luaO_verror' */
-#define MAX_VERROR	280
 
-/* this function needs to handle only '%d' and '%.XXs' formats */
-void luaO_verror (lua_State *L, const char *fmt, ...) {
+static void pushstr (lua_State *L, const char *str) {
+  setsvalue2s(L->top, luaS_new(L, str));
+  incr_top(L);
+}
+
+
+/* this function handles only `%d', `%c', %f, and `%s' formats */
+const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
+  int n = 1;
+  pushstr(L, "");
+  for (;;) {
+    const char *e = strchr(fmt, '%');
+    if (e == NULL) break;
+    setsvalue2s(L->top, luaS_newlstr(L, fmt, e-fmt));
+    incr_top(L);
+    switch (*(e+1)) {
+      case 's':
+        pushstr(L, va_arg(argp, char *));
+        break;
+      case 'c': {
+        char buff[2];
+        buff[0] = cast(char, va_arg(argp, int));
+        buff[1] = '\0';
+        pushstr(L, buff);
+        break;
+      }
+      case 'd':
+        setnvalue(L->top, cast(lua_Number, va_arg(argp, int)));
+        incr_top(L);
+        break;
+      case 'f':
+        setnvalue(L->top, cast(lua_Number, va_arg(argp, l_uacNumber)));
+        incr_top(L);
+        break;
+      case '%':
+        pushstr(L, "%");
+        break;
+      default: lua_assert(0);
+    }
+    n += 2;
+    fmt = e+2;
+  }
+  pushstr(L, fmt);
+  luaV_concat(L, n+1, L->top - L->base - 1);
+  L->top -= n;
+  return svalue(L->top - 1);
+}
+
+
+const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
+  const char *msg;
   va_list argp;
-  char buff[MAX_VERROR];  /* to hold formatted message */
   va_start(argp, fmt);
-  vsprintf(buff, fmt, argp);
+  msg = luaO_pushvfstring(L, fmt, argp);
   va_end(argp);
-  lua_error(L, buff);
+  return msg;
 }
 
 
@@ -95,31 +165,31 @@ void luaO_chunkid (char *out, const char *source, int bufflen) {
     strncpy(out, source+1, bufflen);  /* remove first char */
     out[bufflen-1] = '\0';  /* ensures null termination */
   }
-  else {
+  else {  /* out = "source", or "...source" */
     if (*source == '@') {
       int l;
       source++;  /* skip the `@' */
-      bufflen -= sizeof("file `...%s'");
+      bufflen -= sizeof(" `...' ");
       l = strlen(source);
+      strcpy(out, "");
       if (l>bufflen) {
         source += (l-bufflen);  /* get last part of file name */
-        sprintf(out, "file `...%.99s'", source);
+        strcat(out, "...");
       }
-      else
-        sprintf(out, "file `%.99s'", source);
+      strcat(out, source);
     }
-    else {
+    else {  /* out = [string "string"] */
       int len = strcspn(source, "\n");  /* stop at first newline */
-      bufflen -= sizeof("string \"%.*s...\"");
+      bufflen -= sizeof(" [string \"...\"] ");
       if (len > bufflen) len = bufflen;
+      strcpy(out, "[string \"");
       if (source[len] != '\0') {  /* must truncate? */
-        strcpy(out, "string \"");
-        out += strlen(out);
-        strncpy(out, source, len);
-        strcpy(out+len, "...\"");
+        strncat(out, source, len);
+        strcat(out, "...");
       }
       else
-        sprintf(out, "string \"%.99s\"", source);
+        strcat(out, source);
+      strcat(out, "\"]");
     }
   }
 }
diff --git a/src/lobject.h b/src/lobject.h
index cb232c77..321a7e06 100644
--- a/src/lobject.h
+++ b/src/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 1.82 2000/10/30 17:49:19 roberto Exp $
+** $Id: lobject.h,v 1.159 2003/03/18 12:50:04 roberto Exp $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -12,115 +12,222 @@
 #include "lua.h"
 
 
-#ifdef LUA_DEBUG
-#undef NDEBUG
-#include <assert.h>
-#define LUA_INTERNALERROR(s)	assert(((void)s,0))
-#define LUA_ASSERT(c,s)		assert(((void)s,(c)))
-#else
-#define LUA_INTERNALERROR(s)	/* empty */
-#define LUA_ASSERT(c,s)		/* empty */
-#endif
+/* tags for values visible from Lua */
+#define NUM_TAGS	LUA_TTHREAD
 
 
-#ifdef LUA_DEBUG
-/* to avoid warnings, and make sure value is really unused */
-#define UNUSED(x)	(x=0, (void)(x))
-#else
-#define UNUSED(x)	((void)(x))	/* to avoid warnings */
-#endif
+/*
+** Extra tags for non-values
+*/
+#define LUA_TPROTO	(NUM_TAGS+1)
+#define LUA_TUPVAL	(NUM_TAGS+2)
+
+
+/*
+** Union of all collectable objects
+*/
+typedef union GCObject GCObject;
 
 
-/* mark for closures active in the stack */
-#define LUA_TMARK	6
+/*
+** Common Header for all collectable objects (in macro form, to be
+** included in other objects)
+*/
+#define CommonHeader	GCObject *next; lu_byte tt; lu_byte marked
 
 
-/* tags for values visible from Lua == first user-created tag */
-#define NUM_TAGS	6
+/*
+** Common header in struct form
+*/
+typedef struct GCheader {
+  CommonHeader;
+} GCheader;
 
 
-/* check whether `t' is a mark */
-#define is_T_MARK(t)	((t) == LUA_TMARK)
 
 
+/*
+** Union of all Lua values
+*/
 typedef union {
-  struct TString *ts;	/* LUA_TSTRING, LUA_TUSERDATA */
-  struct Closure *cl;	/* LUA_TFUNCTION */
-  struct Hash *a;	/* LUA_TTABLE */
-  struct CallInfo *i;	/* LUA_TLMARK */
-  Number n;		/* LUA_TNUMBER */
+  GCObject *gc;
+  void *p;
+  lua_Number n;
+  int b;
 } Value;
 
 
-/* Macros to access values */
-#define ttype(o)        ((o)->ttype)
-#define nvalue(o)       ((o)->value.n)
-#define tsvalue(o)      ((o)->value.ts)
-#define clvalue(o)      ((o)->value.cl)
-#define hvalue(o)       ((o)->value.a)
-#define infovalue(o)	((o)->value.i)
-#define svalue(o)       (tsvalue(o)->str)
-
-
+/*
+** Lua values (or `tagged objects')
+*/
 typedef struct lua_TObject {
-  int ttype;
+  int tt;
   Value value;
 } TObject;
 
 
+/* Macros to test type */
+#define ttisnil(o)	(ttype(o) == LUA_TNIL)
+#define ttisnumber(o)	(ttype(o) == LUA_TNUMBER)
+#define ttisstring(o)	(ttype(o) == LUA_TSTRING)
+#define ttistable(o)	(ttype(o) == LUA_TTABLE)
+#define ttisfunction(o)	(ttype(o) == LUA_TFUNCTION)
+#define ttisboolean(o)	(ttype(o) == LUA_TBOOLEAN)
+#define ttisuserdata(o)	(ttype(o) == LUA_TUSERDATA)
+#define ttisthread(o)	(ttype(o) == LUA_TTHREAD)
+#define ttislightuserdata(o)	(ttype(o) == LUA_TLIGHTUSERDATA)
+
+/* Macros to access values */
+#define ttype(o)	((o)->tt)
+#define gcvalue(o)	check_exp(iscollectable(o), (o)->value.gc)
+#define pvalue(o)	check_exp(ttislightuserdata(o), (o)->value.p)
+#define nvalue(o)	check_exp(ttisnumber(o), (o)->value.n)
+#define tsvalue(o)	check_exp(ttisstring(o), &(o)->value.gc->ts)
+#define uvalue(o)	check_exp(ttisuserdata(o), &(o)->value.gc->u)
+#define clvalue(o)	check_exp(ttisfunction(o), &(o)->value.gc->cl)
+#define hvalue(o)	check_exp(ttistable(o), &(o)->value.gc->h)
+#define bvalue(o)	check_exp(ttisboolean(o), (o)->value.b)
+#define thvalue(o)	check_exp(ttisthread(o), &(o)->value.gc->th)
+
+#define l_isfalse(o)	(ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
+
+/* Macros to set values */
+#define setnvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TNUMBER; i_o->value.n=(x); }
+
+#define chgnvalue(obj,x) \
+	check_exp(ttype(obj)==LUA_TNUMBER, (obj)->value.n=(x))
+
+#define setpvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TLIGHTUSERDATA; i_o->value.p=(x); }
+
+#define setbvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TBOOLEAN; i_o->value.b=(x); }
+
+#define setsvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TSTRING; \
+    i_o->value.gc=cast(GCObject *, (x)); \
+    lua_assert(i_o->value.gc->gch.tt == LUA_TSTRING); }
+
+#define setuvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TUSERDATA; \
+    i_o->value.gc=cast(GCObject *, (x)); \
+    lua_assert(i_o->value.gc->gch.tt == LUA_TUSERDATA); }
+
+#define setthvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TTHREAD; \
+    i_o->value.gc=cast(GCObject *, (x)); \
+    lua_assert(i_o->value.gc->gch.tt == LUA_TTHREAD); }
+
+#define setclvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TFUNCTION; \
+    i_o->value.gc=cast(GCObject *, (x)); \
+    lua_assert(i_o->value.gc->gch.tt == LUA_TFUNCTION); }
+
+#define sethvalue(obj,x) \
+  { TObject *i_o=(obj); i_o->tt=LUA_TTABLE; \
+    i_o->value.gc=cast(GCObject *, (x)); \
+    lua_assert(i_o->value.gc->gch.tt == LUA_TTABLE); }
+
+#define setnilvalue(obj) ((obj)->tt=LUA_TNIL)
+
+
+
 /*
-** String headers for string table
+** for internal debug only
+*/
+#define checkconsistency(obj) \
+  lua_assert(!iscollectable(obj) || (ttype(obj) == (obj)->value.gc->gch.tt))
+
+
+#define setobj(obj1,obj2) \
+  { const TObject *o2=(obj2); TObject *o1=(obj1); \
+    checkconsistency(o2); \
+    o1->tt=o2->tt; o1->value = o2->value; }
+
+
+/*
+** different types of sets, according to destination
 */
 
+/* from stack to (same) stack */
+#define setobjs2s	setobj
+/* to stack (not from same stack) */
+#define setobj2s	setobj
+#define setsvalue2s	setsvalue
+/* from table to same table */
+#define setobjt2t	setobj
+/* to table */
+#define setobj2t	setobj
+/* to new object */
+#define setobj2n	setobj
+#define setsvalue2n	setsvalue
+
+#define setttype(obj, tt) (ttype(obj) = (tt))
+
+
+#define iscollectable(o)	(ttype(o) >= LUA_TSTRING)
+
+
+
+typedef TObject *StkId;  /* index to stack elements */
+
+
 /*
-** most `malloc' libraries allocate memory in blocks of 8 bytes. TSPACK
-** tries to make sizeof(TString) a multiple of this granularity, to reduce
-** waste of space.
+** String headers for string table
 */
-#define TSPACK	((int)sizeof(int))
-
-typedef struct TString {
-  union {
-    struct {  /* for strings */
-      unsigned long hash;
-      int constindex;  /* hint to reuse constants */
-    } s;
-    struct {  /* for userdata */
-      int tag;
-      void *value;
-    } d;
-  } u;
-  size_t len;
-  struct TString *nexthash;  /* chain for hash table */
-  int marked;
-  char str[TSPACK];   /* variable length string!! must be the last field! */
+typedef union TString {
+  L_Umaxalign dummy;  /* ensures maximum alignment for strings */
+  struct {
+    CommonHeader;
+    lu_byte reserved;
+    lu_hash hash;
+    size_t len;
+  } tsv;
 } TString;
 
 
+#define getstr(ts)	cast(const char *, (ts) + 1)
+#define svalue(o)       getstr(tsvalue(o))
+
+
+
+typedef union Udata {
+  L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
+  struct {
+    CommonHeader;
+    struct Table *metatable;
+    size_t len;
+  } uv;
+} Udata;
+
+
+
+
 /*
 ** Function Prototypes
 */
 typedef struct Proto {
-  Number *knum;  /* Number numbers used by the function */
-  int nknum;  /* size of `knum' */
-  struct TString **kstr;  /* strings used by the function */
-  int nkstr;  /* size of `kstr' */
-  struct Proto **kproto;  /* functions defined inside the function */
-  int nkproto;  /* size of `kproto' */
+  CommonHeader;
+  TObject *k;  /* constants used by the function */
   Instruction *code;
-  int ncode;  /* size of `code'; when 0 means an incomplete `Proto' */
-  short numparams;
-  short is_vararg;
-  short maxstacksize;
-  short marked;
-  struct Proto *next;
-  /* debug information */
+  struct Proto **p;  /* functions defined inside the function */
   int *lineinfo;  /* map from opcodes to source lines */
-  int nlineinfo;  /* size of `lineinfo' */
-  int nlocvars;
   struct LocVar *locvars;  /* information about local variables */
-  int lineDefined;
+  TString **upvalues;  /* upvalue names */
   TString  *source;
+  int sizeupvalues;
+  int sizek;  /* size of `k' */
+  int sizecode;
+  int sizelineinfo;
+  int sizep;  /* size of `p' */
+  int sizelocvars;
+  int lineDefined;
+  GCObject *gclist;
+  lu_byte nups;  /* number of upvalues */
+  lu_byte numparams;
+  lu_byte is_vararg;
+  lu_byte maxstacksize;
 } Proto;
 
 
@@ -131,73 +238,98 @@ typedef struct LocVar {
 } LocVar;
 
 
+
+/*
+** Upvalues
+*/
+
+typedef struct UpVal {
+  CommonHeader;
+  TObject *v;  /* points to stack or to its own value */
+  TObject value;  /* the value (when closed) */
+} UpVal;
+
+
 /*
 ** Closures
 */
-typedef struct Closure {
-  union {
-    lua_CFunction c;  /* C functions */
-    struct Proto *l;  /* Lua functions */
-  } f;
-  struct Closure *next;
-  struct Closure *mark;  /* marked closures (point to itself when not marked) */
-  short isC;  /* 0 for Lua functions, 1 for C functions */
-  short nupvalues;
+
+#define ClosureHeader \
+	CommonHeader; lu_byte isC; lu_byte nupvalues; GCObject *gclist
+
+typedef struct CClosure {
+  ClosureHeader;
+  lua_CFunction f;
   TObject upvalue[1];
+} CClosure;
+
+
+typedef struct LClosure {
+  ClosureHeader;
+  struct Proto *p;
+  TObject g;  /* global table for this closure */
+  UpVal *upvals[1];
+} LClosure;
+
+
+typedef union Closure {
+  CClosure c;
+  LClosure l;
 } Closure;
 
 
-#define iscfunction(o)	(ttype(o) == LUA_TFUNCTION && clvalue(o)->isC)
+#define iscfunction(o)	(ttype(o) == LUA_TFUNCTION && clvalue(o)->c.isC)
+#define isLfunction(o)	(ttype(o) == LUA_TFUNCTION && !clvalue(o)->c.isC)
+
 
+/*
+** Tables
+*/
 
 typedef struct Node {
-  TObject key;
-  TObject val;
+  TObject i_key;
+  TObject i_val;
   struct Node *next;  /* for chaining */
 } Node;
 
-typedef struct Hash {
+
+typedef struct Table {
+  CommonHeader;
+  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */ 
+  lu_byte lsizenode;  /* log2 of size of `node' array */
+  struct Table *metatable;
+  TObject *array;  /* array part */
   Node *node;
-  int htag;
-  int size;
   Node *firstfree;  /* this position is free; all positions after it are full */
-  struct Hash *next;
-  struct Hash *mark;  /* marked tables (point to itself when not marked) */
-} Hash;
-
+  GCObject *gclist;
+  int sizearray;  /* size of `array' array */
+} Table;
 
-/* unmarked tables and closures are represented by pointing `mark' to
-** themselves
-*/
-#define ismarked(x)	((x)->mark != (x))
 
 
 /*
-** informations about a call (for debugging)
+** `module' operation for hashing (size is always a power of 2)
 */
-typedef struct CallInfo {
-  struct Closure *func;  /* function being called */
-  const Instruction **pc;  /* current pc of called function */
-  int lastpc;  /* last pc traced */
-  int line;  /* current line */
-  int refi;  /* current index in `lineinfo' */
-} CallInfo;
+#define lmod(s,size) \
+	check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1))))
 
 
-extern const TObject luaO_nilobject;
-extern const char *const luaO_typenames[];
+#define twoto(x)	(1<<(x))
+#define sizenode(t)	(twoto((t)->lsizenode))
 
 
-#define luaO_typename(o)	(luaO_typenames[ttype(o)])
 
+extern const TObject luaO_nilobject;
 
-lint32 luaO_power2 (lint32 n);
-char *luaO_openspace (lua_State *L, size_t n);
+int luaO_log2 (unsigned int x);
+int luaO_int2fb (unsigned int x);
+#define fb2int(x)	(((x) & 7) << ((x) >> 3))
 
-int luaO_equalObj (const TObject *t1, const TObject *t2);
-int luaO_str2d (const char *s, Number *result);
+int luaO_rawequalObj (const TObject *t1, const TObject *t2);
+int luaO_str2d (const char *s, lua_Number *result);
 
-void luaO_verror (lua_State *L, const char *fmt, ...);
+const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp);
+const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
 void luaO_chunkid (char *out, const char *source, int len);
 
 
diff --git a/src/lopcodes.c b/src/lopcodes.c
new file mode 100644
index 00000000..993e426d
--- /dev/null
+++ b/src/lopcodes.c
@@ -0,0 +1,102 @@
+/*
+** $Id: lopcodes.c,v 1.22 2002/12/04 17:38:31 roberto Exp $
+** extracted automatically from lopcodes.h by mkprint.lua
+** DO NOT EDIT
+** See Copyright Notice in lua.h
+*/
+
+
+#define lopcodes_c
+
+#include "lua.h"
+
+#include "lobject.h"
+#include "lopcodes.h"
+
+
+#ifdef LUA_OPNAMES
+
+const char *const luaP_opnames[] = {
+  "MOVE",
+  "LOADK",
+  "LOADBOOL",
+  "LOADNIL",
+  "GETUPVAL",
+  "GETGLOBAL",
+  "GETTABLE",
+  "SETGLOBAL",
+  "SETUPVAL",
+  "SETTABLE",
+  "NEWTABLE",
+  "SELF",
+  "ADD",
+  "SUB",
+  "MUL",
+  "DIV",
+  "POW",
+  "UNM",
+  "NOT",
+  "CONCAT",
+  "JMP",
+  "EQ",
+  "LT",
+  "LE",
+  "TEST",
+  "CALL",
+  "TAILCALL",
+  "RETURN",
+  "FORLOOP",
+  "TFORLOOP",
+  "TFORPREP",
+  "SETLIST",
+  "SETLISTO",
+  "CLOSE",
+  "CLOSURE"
+};
+
+#endif
+
+#define opmode(t,b,bk,ck,sa,k,m) (((t)<<OpModeT) | \
+   ((b)<<OpModeBreg) | ((bk)<<OpModeBrk) | ((ck)<<OpModeCrk) | \
+   ((sa)<<OpModesetA) | ((k)<<OpModeK) | (m))
+
+
+const lu_byte luaP_opmodes[NUM_OPCODES] = {
+/*       T  B Bk Ck sA  K  mode			   opcode    */
+  opmode(0, 1, 0, 0, 1, 0, iABC)		/* OP_MOVE */
+ ,opmode(0, 0, 0, 0, 1, 1, iABx)		/* OP_LOADK */
+ ,opmode(0, 0, 0, 0, 1, 0, iABC)		/* OP_LOADBOOL */
+ ,opmode(0, 1, 0, 0, 1, 0, iABC)		/* OP_LOADNIL */
+ ,opmode(0, 0, 0, 0, 1, 0, iABC)		/* OP_GETUPVAL */
+ ,opmode(0, 0, 0, 0, 1, 1, iABx)		/* OP_GETGLOBAL */
+ ,opmode(0, 1, 0, 1, 1, 0, iABC)		/* OP_GETTABLE */
+ ,opmode(0, 0, 0, 0, 0, 1, iABx)		/* OP_SETGLOBAL */
+ ,opmode(0, 0, 0, 0, 0, 0, iABC)		/* OP_SETUPVAL */
+ ,opmode(0, 0, 1, 1, 0, 0, iABC)		/* OP_SETTABLE */
+ ,opmode(0, 0, 0, 0, 1, 0, iABC)		/* OP_NEWTABLE */
+ ,opmode(0, 1, 0, 1, 1, 0, iABC)		/* OP_SELF */
+ ,opmode(0, 0, 1, 1, 1, 0, iABC)		/* OP_ADD */
+ ,opmode(0, 0, 1, 1, 1, 0, iABC)		/* OP_SUB */
+ ,opmode(0, 0, 1, 1, 1, 0, iABC)		/* OP_MUL */
+ ,opmode(0, 0, 1, 1, 1, 0, iABC)		/* OP_DIV */
+ ,opmode(0, 0, 1, 1, 1, 0, iABC)		/* OP_POW */
+ ,opmode(0, 1, 0, 0, 1, 0, iABC)		/* OP_UNM */
+ ,opmode(0, 1, 0, 0, 1, 0, iABC)		/* OP_NOT */
+ ,opmode(0, 1, 0, 1, 1, 0, iABC)		/* OP_CONCAT */
+ ,opmode(0, 0, 0, 0, 0, 0, iAsBx)		/* OP_JMP */
+ ,opmode(1, 0, 1, 1, 0, 0, iABC)		/* OP_EQ */
+ ,opmode(1, 0, 1, 1, 0, 0, iABC)		/* OP_LT */
+ ,opmode(1, 0, 1, 1, 0, 0, iABC)		/* OP_LE */
+ ,opmode(1, 1, 0, 0, 1, 0, iABC)		/* OP_TEST */
+ ,opmode(0, 0, 0, 0, 0, 0, iABC)		/* OP_CALL */
+ ,opmode(0, 0, 0, 0, 0, 0, iABC)		/* OP_TAILCALL */
+ ,opmode(0, 0, 0, 0, 0, 0, iABC)		/* OP_RETURN */
+ ,opmode(0, 0, 0, 0, 0, 0, iAsBx)		/* OP_FORLOOP */
+ ,opmode(1, 0, 0, 0, 0, 0, iABC)		/* OP_TFORLOOP */
+ ,opmode(0, 0, 0, 0, 0, 0, iAsBx)		/* OP_TFORPREP */
+ ,opmode(0, 0, 0, 0, 0, 0, iABx)		/* OP_SETLIST */
+ ,opmode(0, 0, 0, 0, 0, 0, iABx)		/* OP_SETLISTO */
+ ,opmode(0, 0, 0, 0, 0, 0, iABC)		/* OP_CLOSE */
+ ,opmode(0, 0, 0, 0, 1, 0, iABx)		/* OP_CLOSURE */
+};
+
diff --git a/src/lopcodes.h b/src/lopcodes.h
index 2df72ce7..0b6b58f3 100644
--- a/src/lopcodes.h
+++ b/src/lopcodes.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.h,v 1.68 2000/10/24 16:05:59 roberto Exp $
+** $Id: lopcodes.h,v 1.102 2002/08/21 18:56:09 roberto Exp $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -12,29 +12,58 @@
 
 /*===========================================================================
   We assume that instructions are unsigned numbers.
-  All instructions have an opcode in the first 6 bits. Moreover,
-  an instruction can have 0, 1, or 2 arguments. Instructions can
-  have the following types:
-  type 0: no arguments
-  type 1: 1 unsigned argument in the higher bits (called `U')
-  type 2: 1 signed argument in the higher bits          (`S')
-  type 3: 1st unsigned argument in the higher bits      (`A')
-          2nd unsigned argument in the middle bits      (`B')
+  All instructions have an opcode in the first 6 bits.
+  Instructions can have the following fields:
+	`A' : 8 bits
+	`B' : 9 bits
+	`C' : 9 bits
+	`Bx' : 18 bits (`B' and `C' together)
+	`sBx' : signed Bx
 
   A signed argument is represented in excess K; that is, the number
   value is the unsigned value minus K. K is exactly the maximum value
   for that argument (so that -max is represented by 0, and +max is
   represented by 2*max), which is half the maximum for the corresponding
   unsigned argument.
-
-  The size of each argument is defined in `llimits.h'. The usual is an
-  instruction with 32 bits, U arguments with 26 bits (32-6), B arguments
-  with 9 bits, and A arguments with 17 bits (32-6-9). For small
-  installations, the instruction size can be 16, so U has 10 bits,
-  and A and B have 5 bits each.
 ===========================================================================*/
 
 
+enum OpMode {iABC, iABx, iAsBx};  /* basic instruction format */
+
+
+/*
+** size and position of opcode arguments.
+*/
+#define SIZE_C		9
+#define SIZE_B		9
+#define SIZE_Bx		(SIZE_C + SIZE_B)
+#define SIZE_A		8
+
+#define SIZE_OP		6
+
+#define POS_C		SIZE_OP
+#define POS_B		(POS_C + SIZE_C)
+#define POS_Bx		POS_C
+#define POS_A		(POS_B + SIZE_B)
+
+
+/*
+** limits for opcode arguments.
+** we use (signed) int to manipulate most arguments,
+** so they must fit in BITS_INT-1 bits (-1 for sign)
+*/
+#if SIZE_Bx < BITS_INT-1
+#define MAXARG_Bx        ((1<<SIZE_Bx)-1)
+#define MAXARG_sBx        (MAXARG_Bx>>1)         /* `sBx' is signed */
+#else
+#define MAXARG_Bx        MAX_INT
+#define MAXARG_sBx        MAX_INT
+#endif
+
+
+#define MAXARG_A        ((1<<SIZE_A)-1)
+#define MAXARG_B        ((1<<SIZE_B)-1)
+#define MAXARG_C        ((1<<SIZE_C)-1)
 
 
 /* creates a mask with `n' 1 bits at position `p' */
@@ -47,122 +76,163 @@
 ** the following macros help to manipulate instructions
 */
 
-#define CREATE_0(o)	 ((Instruction)(o))
-#define GET_OPCODE(i)	((OpCode)((i)&MASK1(SIZE_OP,0)))
-#define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,0)) | (Instruction)(o)))
+#define GET_OPCODE(i)	(cast(OpCode, (i)&MASK1(SIZE_OP,0)))
+#define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,0)) | cast(Instruction, o)))
 
-#define CREATE_U(o,u)	 ((Instruction)(o) | ((Instruction)(u)<<POS_U))
-#define GETARG_U(i)	((int)((i)>>POS_U))
-#define SETARG_U(i,u)	((i) = (((i)&MASK0(SIZE_U,POS_U)) | \
-                               ((Instruction)(u)<<POS_U)))
+#define GETARG_A(i)	(cast(int, (i)>>POS_A))
+#define SETARG_A(i,u)	((i) = (((i)&MASK0(SIZE_A,POS_A)) | \
+		((cast(Instruction, u)<<POS_A)&MASK1(SIZE_A,POS_A))))
 
-#define CREATE_S(o,s)	CREATE_U((o),(s)+MAXARG_S)
-#define GETARG_S(i)	(GETARG_U(i)-MAXARG_S)
-#define SETARG_S(i,s)	SETARG_U((i),(s)+MAXARG_S)
+#define GETARG_B(i)	(cast(int, ((i)>>POS_B) & MASK1(SIZE_B,0)))
+#define SETARG_B(i,b)	((i) = (((i)&MASK0(SIZE_B,POS_B)) | \
+		((cast(Instruction, b)<<POS_B)&MASK1(SIZE_B,POS_B))))
+
+#define GETARG_C(i)	(cast(int, ((i)>>POS_C) & MASK1(SIZE_C,0)))
+#define SETARG_C(i,b)	((i) = (((i)&MASK0(SIZE_C,POS_C)) | \
+		((cast(Instruction, b)<<POS_C)&MASK1(SIZE_C,POS_C))))
+
+#define GETARG_Bx(i)	(cast(int, ((i)>>POS_Bx) & MASK1(SIZE_Bx,0)))
+#define SETARG_Bx(i,b)	((i) = (((i)&MASK0(SIZE_Bx,POS_Bx)) | \
+		((cast(Instruction, b)<<POS_Bx)&MASK1(SIZE_Bx,POS_Bx))))
+
+#define GETARG_sBx(i)	(GETARG_Bx(i)-MAXARG_sBx)
+#define SETARG_sBx(i,b)	SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
+
+
+#define CREATE_ABC(o,a,b,c)	(cast(Instruction, o) \
+			| (cast(Instruction, a)<<POS_A) \
+			| (cast(Instruction, b)<<POS_B) \
+			| (cast(Instruction, c)<<POS_C))
+
+#define CREATE_ABx(o,a,bc)	(cast(Instruction, o) \
+			| (cast(Instruction, a)<<POS_A) \
+			| (cast(Instruction, bc)<<POS_Bx))
 
 
-#define CREATE_AB(o,a,b) ((Instruction)(o) | ((Instruction)(a)<<POS_A) \
-                                           |  ((Instruction)(b)<<POS_B))
-#define GETARG_A(i)	((int)((i)>>POS_A))
-#define SETARG_A(i,a)	((i) = (((i)&MASK0(SIZE_A,POS_A)) | \
-                               ((Instruction)(a)<<POS_A)))
-#define GETARG_B(i)	((int)(((i)>>POS_B) & MASK1(SIZE_B,0)))
-#define SETARG_B(i,b)	((i) = (((i)&MASK0(SIZE_B,POS_B)) | \
-                               ((Instruction)(b)<<POS_B)))
 
 
 /*
-** K = U argument used as index to `kstr'
-** J = S argument used as jump offset (relative to pc of next instruction)
-** L = unsigned argument used as index of local variable
-** N = U argument used as index to `knum'
+** invalid register that fits in 8 bits
+*/
+#define NO_REG		MAXARG_A
+
+
+/*
+** R(x) - register
+** Kst(x) - constant (in constant table)
+** RK(x) == if x < MAXSTACK then R(x) else Kst(x-MAXSTACK)
+*/
+
+
+/*
+** grep "ORDER OP" if you change these enums
 */
 
 typedef enum {
 /*----------------------------------------------------------------------
-name		args	stack before	stack after	side effects
+name		args	description
 ------------------------------------------------------------------------*/
-OP_END,/*	-	-		(return)	no results	*/
-OP_RETURN,/*	U	v_n-v_x(at u)	(return)	returns v_x-v_n	*/
+OP_MOVE,/*	A B	R(A) := R(B)					*/
+OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
+OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) PC++			*/
+OP_LOADNIL,/*	A B	R(A) := ... := R(B) := nil			*/
+OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
 
-OP_CALL,/*	A B	v_n-v_1 f(at a)	r_b-r_1		f(v1,...,v_n)	*/
-OP_TAILCALL,/*	A B	v_n-v_1 f(at a)	(return)	f(v1,...,v_n)	*/
+OP_GETGLOBAL,/*	A Bx	R(A) := Gbl[Kst(Bx)]				*/
+OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
 
-OP_PUSHNIL,/*	U	-		nil_1-nil_u			*/
-OP_POP,/*	U	a_u-a_1		-				*/
+OP_SETGLOBAL,/*	A Bx	Gbl[Kst(Bx)] := R(A)				*/
+OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
+OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
 
-OP_PUSHINT,/*	S	-		(Number)s			*/
-OP_PUSHSTRING,/* K	-		KSTR[k]				*/
-OP_PUSHNUM,/*	N	-		KNUM[n]				*/
-OP_PUSHNEGNUM,/* N	-		-KNUM[n]			*/
+OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
 
-OP_PUSHUPVALUE,/* U	-		Closure[u]			*/
+OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
 
-OP_GETLOCAL,/*	L	-		LOC[l]				*/
-OP_GETGLOBAL,/*	K	-		VAR[KSTR[k]]			*/
+OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
+OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
+OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
+OP_DIV,/*	A B C	R(A) := RK(B) / RK(C)				*/
+OP_POW,/*	A B C	R(A) := RK(B) ^ RK(C)				*/
+OP_UNM,/*	A B	R(A) := -R(B)					*/
+OP_NOT,/*	A B	R(A) := not R(B)				*/
 
-OP_GETTABLE,/*	-	i t		t[i]				*/
-OP_GETDOTTED,/*	K	t		t[KSTR[k]]			*/
-OP_GETINDEXED,/* L	t		t[LOC[l]]			*/
-OP_PUSHSELF,/*	K	t		t t[KSTR[k]]			*/
+OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
 
-OP_CREATETABLE,/* U	-		newarray(size = u)		*/
+OP_JMP,/*	sBx	PC += sBx					*/
 
-OP_SETLOCAL,/*	L	x		-		LOC[l]=x	*/
-OP_SETGLOBAL,/*	K	x		-		VAR[KSTR[k]]=x	*/
-OP_SETTABLE,/*	A B	v a_a-a_1 i t	(pops b values)	t[i]=v		*/
+OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
+OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++  		*/
+OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++  		*/
 
-OP_SETLIST,/*	A B	v_b-v_1 t	t		t[i+a*FPF]=v_i	*/
-OP_SETMAP,/*	U	v_u k_u - v_1 k_1 t	t	t[k_i]=v_i	*/
+OP_TEST,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/ 
 
-OP_ADD,/*	-	y x		x+y				*/
-OP_ADDI,/*	S	x		x+s				*/
-OP_SUB,/*	-	y x		x-y				*/
-OP_MULT,/*	-	y x		x*y				*/
-OP_DIV,/*	-	y x		x/y				*/
-OP_POW,/*	-	y x		x^y				*/
-OP_CONCAT,/*	U	v_u-v_1		v1..-..v_u			*/
-OP_MINUS,/*	-	x		-x				*/
-OP_NOT,/*	-	x		(x==nil)? 1 : nil		*/
+OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
+OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
+OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
 
-OP_JMPNE,/*	J	y x		-		(x~=y)? PC+=s	*/
-OP_JMPEQ,/*	J	y x		-		(x==y)? PC+=s	*/
-OP_JMPLT,/*	J	y x		-		(x<y)? PC+=s	*/
-OP_JMPLE,/*	J	y x		-		(x<y)? PC+=s	*/
-OP_JMPGT,/*	J	y x		-		(x>y)? PC+=s	*/
-OP_JMPGE,/*	J	y x		-		(x>=y)? PC+=s	*/
+OP_FORLOOP,/*	A sBx	R(A)+=R(A+2); if R(A) <?= R(A+1) then PC+= sBx	*/
 
-OP_JMPT,/*	J	x		-		(x~=nil)? PC+=s	*/
-OP_JMPF,/*	J	x		-		(x==nil)? PC+=s	*/
-OP_JMPONT,/*	J	x		(x~=nil)? x : -	(x~=nil)? PC+=s	*/
-OP_JMPONF,/*	J	x		(x==nil)? x : -	(x==nil)? PC+=s	*/
-OP_JMP,/*	J	-		-		PC+=s		*/
+OP_TFORLOOP,/*	A C	R(A+2), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); 
+                        if R(A+2) ~= nil then pc++			*/
+OP_TFORPREP,/*	A sBx	if type(R(A)) == table then R(A+1):=R(A), R(A):=next;
+			PC += sBx					*/
 
-OP_PUSHNILJMP,/* -	-		nil		PC++;		*/
+OP_SETLIST,/*	A Bx	R(A)[Bx-Bx%FPF+i] := R(A+i), 1 <= i <= Bx%FPF+1	*/
+OP_SETLISTO,/*	A Bx							*/
 
-OP_FORPREP,/*	J							*/
-OP_FORLOOP,/*	J							*/
+OP_CLOSE,/*	A 	close all variables in the stack up to (>=) R(A)*/
+OP_CLOSURE/*	A Bx	R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n))	*/
+} OpCode;
 
-OP_LFORPREP,/*	J							*/
-OP_LFORLOOP,/*	J							*/
 
-OP_CLOSURE/*	A B	v_b-v_1		closure(KPROTO[a], v_1-v_b)	*/
+#define NUM_OPCODES	(cast(int, OP_CLOSURE+1))
+
 
-} OpCode;
 
-#define NUM_OPCODES	((int)OP_CLOSURE+1)
+/*===========================================================================
+  Notes:
+  (1) In OP_CALL, if (B == 0) then B = top. C is the number of returns - 1,
+      and can be 0: OP_CALL then sets `top' to last_result+1, so
+      next open instruction (OP_CALL, OP_RETURN, OP_SETLIST) may use `top'.
+
+  (2) In OP_RETURN, if (B == 0) then return up to `top'
+
+  (3) For comparisons, B specifies what conditions the test should accept.
+
+  (4) All `skips' (pc++) assume that next instruction is a jump
+===========================================================================*/
 
 
-#define ISJUMP(o)	(OP_JMPNE <= (o) && (o) <= OP_JMP)
+/*
+** masks for instruction properties
+*/  
+enum OpModeMask {
+  OpModeBreg = 2,       /* B is a register */
+  OpModeBrk,		/* B is a register/constant */
+  OpModeCrk,           /* C is a register/constant */
+  OpModesetA,           /* instruction set register A */
+  OpModeK,              /* Bx is a constant */
+  OpModeT		/* operator is a test */
+  
+};
 
 
+extern const lu_byte luaP_opmodes[NUM_OPCODES];
 
-/* special code to fit a LUA_MULTRET inside an argB */
-#define MULT_RET        255	/* (<=MAXARG_B) */
-#if MULT_RET>MAXARG_B
-#undef MULT_RET
-#define MULT_RET	MAXARG_B
+#define getOpMode(m)            (cast(enum OpMode, luaP_opmodes[m] & 3))
+#define testOpMode(m, b)        (luaP_opmodes[m] & (1 << (b)))
+
+
+#ifdef LUA_OPNAMES
+extern const char *const luaP_opnames[];  /* opcode names */
 #endif
 
 
+
+/* number of list items to accumulate before a SETLIST instruction */
+/* (must be a power of 2) */
+#define LFIELDS_PER_FLUSH	32
+
+
 #endif
diff --git a/src/lparser.c b/src/lparser.c
index 67161c86..c1323ecd 100644
--- a/src/lparser.c
+++ b/src/lparser.c
@@ -1,16 +1,18 @@
 /*
-** $Id: lparser.c,v 1.117 2000/11/29 11:57:42 roberto Exp $
-** LL(1) Parser and code generator for Lua
+** $Id: lparser.c,v 1.208 2003/04/03 13:35:34 roberto Exp $
+** Lua Parser
 ** See Copyright Notice in lua.h
 */
 
 
-#include <stdio.h>
 #include <string.h>
 
+#define lparser_c
+
 #include "lua.h"
 
 #include "lcode.h"
+#include "ldebug.h"
 #include "lfunc.h"
 #include "llex.h"
 #include "lmem.h"
@@ -21,35 +23,34 @@
 #include "lstring.h"
 
 
-/*
-** Constructors descriptor:
-** `n' indicates number of elements, and `k' signals whether
-** it is a list constructor (k = 0) or a record constructor (k = 1)
-** or empty (k = ';' or '}')
-*/
-typedef struct Constdesc {
-  int n;
-  int k;
-} Constdesc;
 
 
-typedef struct Breaklabel {
-  struct Breaklabel *previous;  /* chain */
-  int breaklist;
-  int stacklevel;
-} Breaklabel;
+#define getlocvar(fs, i)	((fs)->f->locvars[(fs)->actvar[i]])
+
+
+#define enterlevel(ls)	if (++(ls)->nestlevel > LUA_MAXPARSERLEVEL) \
+		luaX_syntaxerror(ls, "too many syntax levels");
+#define leavelevel(ls)	((ls)->nestlevel--)
 
 
+/*
+** nodes for block list (list of active blocks)
+*/
+typedef struct BlockCnt {
+  struct BlockCnt *previous;  /* chain */
+  int breaklist;  /* list of jumps out of this loop */
+  int nactvar;  /* # active local variables outside the breakable structure */
+  int upval;  /* true if some variable in the block is an upvalue */
+  int isbreakable;  /* true if `block' is a loop */
+} BlockCnt;
+
 
 
 /*
 ** prototypes for recursive non-terminal functions
 */
-static void body (LexState *ls, int needself, int line);
 static void chunk (LexState *ls);
-static void constructor (LexState *ls);
 static void expr (LexState *ls, expdesc *v);
-static void exp1 (LexState *ls);
 
 
 
@@ -65,32 +66,18 @@ static void next (LexState *ls) {
 
 
 static void lookahead (LexState *ls) {
-  LUA_ASSERT(ls->lookahead.token == TK_EOS, "two look-aheads");
+  lua_assert(ls->lookahead.token == TK_EOS);
   ls->lookahead.token = luaX_lex(ls, &ls->lookahead.seminfo);
 }
 
 
 static void error_expected (LexState *ls, int token) {
-  char buff[100], t[TOKEN_LEN];
-  luaX_token2str(token, t);
-  sprintf(buff, "`%.20s' expected", t);
-  luaK_error(ls, buff);
+  luaX_syntaxerror(ls,
+         luaO_pushfstring(ls->L, "`%s' expected", luaX_token2str(ls, token)));
 }
 
 
-static void check (LexState *ls, int c) {
-  if (ls->t.token != c)
-    error_expected(ls, c);
-  next(ls);
-}
-
-
-static void check_condition (LexState *ls, int c, const char *msg) {
-  if (!c) luaK_error(ls, msg);
-}
-
-
-static int optional (LexState *ls, int c) {
+static int testnext (LexState *ls, int c) {
   if (ls->t.token == c) {
     next(ls);
     return 1;
@@ -99,40 +86,26 @@ static int optional (LexState *ls, int c) {
 }
 
 
+static void check (LexState *ls, int c) {
+  if (!testnext(ls, c))
+    error_expected(ls, c);
+}
+
+
+#define check_condition(ls,c,msg)	{ if (!(c)) luaX_syntaxerror(ls, msg); }
+
+
+
 static void check_match (LexState *ls, int what, int who, int where) {
-  if (ls->t.token != what) {
+  if (!testnext(ls, what)) {
     if (where == ls->linenumber)
       error_expected(ls, what);
     else {
-      char buff[100];
-      char t_what[TOKEN_LEN], t_who[TOKEN_LEN];
-      luaX_token2str(what, t_what);
-      luaX_token2str(who, t_who);
-      sprintf(buff, "`%.20s' expected (to close `%.20s' at line %d)",
-              t_what, t_who, where);
-      luaK_error(ls, buff);
+      luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
+             "`%s' expected (to close `%s' at line %d)",
+              luaX_token2str(ls, what), luaX_token2str(ls, who), where));
     }
   }
-  next(ls);
-}
-
-
-static int string_constant (FuncState *fs, TString *s) {
-  Proto *f = fs->f;
-  int c = s->u.s.constindex;
-  if (c >= f->nkstr || f->kstr[c] != s) {
-    luaM_growvector(fs->L, f->kstr, f->nkstr, 1, TString *,
-                    "constant table overflow", MAXARG_U);
-    c = f->nkstr++;
-    f->kstr[c] = s;
-    s->u.s.constindex = c;  /* hint for next time */
-  }
-  return c;
-}
-
-
-static void code_string (LexState *ls, TString *s) {
-  luaK_kstr(ls, string_constant(ls->fs, s));
 }
 
 
@@ -145,182 +118,224 @@ static TString *str_checkname (LexState *ls) {
 }
 
 
-static int checkname (LexState *ls) {
-  return string_constant(ls->fs, str_checkname(ls));
+static void init_exp (expdesc *e, expkind k, int i) {
+  e->f = e->t = NO_JUMP;
+  e->k = k;
+  e->info = i;
+}
+
+
+static void codestring (LexState *ls, expdesc *e, TString *s) {
+  init_exp(e, VK, luaK_stringK(ls->fs, s));
+}
+
+
+static void checkname(LexState *ls, expdesc *e) {
+  codestring(ls, e, str_checkname(ls));
 }
 
 
 static int luaI_registerlocalvar (LexState *ls, TString *varname) {
-  Proto *f = ls->fs->f;
-  luaM_growvector(ls->L, f->locvars, f->nlocvars, 1, LocVar, "", MAX_INT);
-  f->locvars[f->nlocvars].varname = varname;
-  return f->nlocvars++;
+  FuncState *fs = ls->fs;
+  Proto *f = fs->f;
+  luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
+                  LocVar, MAX_INT, "");
+  f->locvars[fs->nlocvars].varname = varname;
+  return fs->nlocvars++;
 }
 
 
 static void new_localvar (LexState *ls, TString *name, int n) {
   FuncState *fs = ls->fs;
-  luaX_checklimit(ls, fs->nactloc+n+1, MAXLOCALS, "local variables");
-  fs->actloc[fs->nactloc+n] = luaI_registerlocalvar(ls, name);
+  luaX_checklimit(ls, fs->nactvar+n+1, MAXVARS, "local variables");
+  fs->actvar[fs->nactvar+n] = luaI_registerlocalvar(ls, name);
 }
 
 
 static void adjustlocalvars (LexState *ls, int nvars) {
   FuncState *fs = ls->fs;
-  while (nvars--)
-    fs->f->locvars[fs->actloc[fs->nactloc++]].startpc = fs->pc;
+  fs->nactvar += nvars;
+  for (; nvars; nvars--) {
+    getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc;
+  }
 }
 
 
-static void removelocalvars (LexState *ls, int nvars) {
+static void removevars (LexState *ls, int tolevel) {
   FuncState *fs = ls->fs;
-  while (nvars--)
-    fs->f->locvars[fs->actloc[--fs->nactloc]].endpc = fs->pc;
+  while (fs->nactvar > tolevel)
+    getlocvar(fs, --fs->nactvar).endpc = fs->pc;
 }
 
 
 static void new_localvarstr (LexState *ls, const char *name, int n) {
-  new_localvar(ls, luaS_newfixed(ls->L, name), n);
+  new_localvar(ls, luaS_new(ls->L, name), n);
 }
 
 
-static int search_local (LexState *ls, TString *n, expdesc *var) {
-  FuncState *fs;
-  int level = 0;
-  for (fs=ls->fs; fs; fs=fs->prev) {
-    int i;
-    for (i=fs->nactloc-1; i >= 0; i--) {
-      if (n == fs->f->locvars[fs->actloc[i]].varname) {
-        var->k = VLOCAL;
-        var->u.index = i;
-        return level;
-      }
-    }
-    level++;  /* `var' not found; check outer level */
-  }
-  var->k = VGLOBAL;  /* not found in any level; must be global */
-  return -1;
+static void create_local (LexState *ls, const char *name) {
+  new_localvarstr(ls, name, 0);
+  adjustlocalvars(ls, 1);
 }
 
 
-static void singlevar (LexState *ls, TString *n, expdesc *var) {
-  int level = search_local(ls, n, var);
-  if (level >= 1)  /* neither local (0) nor global (-1)? */
-    luaX_syntaxerror(ls, "cannot access a variable in outer scope", n->str);
-  else if (level == -1)  /* global? */
-    var->u.index = string_constant(ls->fs, n);
+static int indexupvalue (FuncState *fs, TString *name, expdesc *v) {
+  int i;
+  Proto *f = fs->f;
+  for (i=0; i<f->nups; i++) {
+    if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->info) {
+      lua_assert(fs->f->upvalues[i] == name);
+      return i;
+    }
+  }
+  /* new one */
+  luaX_checklimit(fs->ls, f->nups + 1, MAXUPVALUES, "upvalues");
+  luaM_growvector(fs->L, fs->f->upvalues, f->nups, fs->f->sizeupvalues,
+                  TString *, MAX_INT, "");
+  fs->f->upvalues[f->nups] = name;
+  fs->upvalues[f->nups] = *v;
+  return f->nups++;
 }
 
 
-static int indexupvalue (LexState *ls, expdesc *v) {
-  FuncState *fs = ls->fs;
+static int searchvar (FuncState *fs, TString *n) {
   int i;
-  for (i=0; i<fs->nupvalues; i++) {
-    if (fs->upvalues[i].k == v->k && fs->upvalues[i].u.index == v->u.index)
+  for (i=fs->nactvar-1; i >= 0; i--) {
+    if (n == getlocvar(fs, i).varname)
       return i;
   }
-  /* new one */
-  luaX_checklimit(ls, fs->nupvalues+1, MAXUPVALUES, "upvalues");
-  fs->upvalues[fs->nupvalues] = *v;
-  return fs->nupvalues++;
+  return -1;  /* not found */
 }
 
 
-static void pushupvalue (LexState *ls, TString *n) {
-  FuncState *fs = ls->fs;
-  expdesc v;
-  int level = search_local(ls, n, &v);
-  if (level == -1) {  /* global? */
-    if (fs->prev == NULL)
-      luaX_syntaxerror(ls, "cannot access upvalue in main", n->str);
-    v.u.index = string_constant(fs->prev, n);
+static void markupval (FuncState *fs, int level) {
+  BlockCnt *bl = fs->bl;
+  while (bl && bl->nactvar > level) bl = bl->previous;
+  if (bl) bl->upval = 1;
+}
+
+
+static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
+  if (fs == NULL)  /* no more levels? */
+    init_exp(var, VGLOBAL, NO_REG);  /* default is global variable */
+  else {
+    int v = searchvar(fs, n);  /* look up at current level */
+    if (v >= 0) {
+      init_exp(var, VLOCAL, v);
+      if (!base)
+        markupval(fs, v);  /* local will be used as an upval */
+    }
+    else {  /* not found at current level; try upper one */
+      singlevaraux(fs->prev, n, var, 0);
+      if (var->k == VGLOBAL) {
+        if (base)
+          var->info = luaK_stringK(fs, n);  /* info points to global name */
+      }
+      else {  /* LOCAL or UPVAL */
+        var->info = indexupvalue(fs, n, var);
+        var->k = VUPVAL;  /* upvalue in this level */
+      }
+    }
   }
-  else if (level != 1)
-    luaX_syntaxerror(ls,
-         "upvalue must be global or local to immediately outer scope", n->str);
-  luaK_code1(fs, OP_PUSHUPVALUE, indexupvalue(ls, &v));
 }
 
 
-static void adjust_mult_assign (LexState *ls, int nvars, int nexps) {
+static TString *singlevar (LexState *ls, expdesc *var, int base) {
+  TString *varname = str_checkname(ls);
+  singlevaraux(ls->fs, varname, var, base);
+  return varname;
+}
+
+
+static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
   FuncState *fs = ls->fs;
-  int diff = nexps - nvars;
-  if (nexps > 0 && luaK_lastisopen(fs)) { /* list ends in a function call */
-    diff--;  /* do not count function call itself */
-    if (diff <= 0) {  /* more variables than values? */
-      luaK_setcallreturns(fs, -diff);  /* function call provide extra values */
-      diff = 0;  /* no more difference */
+  int extra = nvars - nexps;
+  if (e->k == VCALL) {
+    extra++;  /* includes call itself */
+    if (extra <= 0) extra = 0;
+    else luaK_reserveregs(fs, extra-1);
+    luaK_setcallreturns(fs, e, extra);  /* call provides the difference */
+  }
+  else {
+    if (e->k != VVOID) luaK_exp2nextreg(fs, e);  /* close last expression */
+    if (extra > 0) {
+      int reg = fs->freereg;
+      luaK_reserveregs(fs, extra);
+      luaK_nil(fs, reg, extra);
     }
-    else  /* more values than variables */
-      luaK_setcallreturns(fs, 0);  /* call should provide no value */
   }
-  /* push or pop eventual difference between list lengths */
-  luaK_adjuststack(fs, diff);
 }
 
 
 static void code_params (LexState *ls, int nparams, int dots) {
   FuncState *fs = ls->fs;
   adjustlocalvars(ls, nparams);
-  luaX_checklimit(ls, fs->nactloc, MAXPARAMS, "parameters");
-  fs->f->numparams = fs->nactloc;  /* `self' could be there already */
-  fs->f->is_vararg = dots;
-  if (dots) {
-    new_localvarstr(ls, "arg", 0);
-    adjustlocalvars(ls, 1);
-  }
-  luaK_deltastack(fs, fs->nactloc);  /* count parameters in the stack */
+  luaX_checklimit(ls, fs->nactvar, MAXPARAMS, "parameters");
+  fs->f->numparams = cast(lu_byte, fs->nactvar);
+  fs->f->is_vararg = cast(lu_byte, dots);
+  if (dots)
+    create_local(ls, "arg");
+  luaK_reserveregs(fs, fs->nactvar);  /* reserve register for parameters */
 }
 
 
-static void enterbreak (FuncState *fs, Breaklabel *bl) {
-  bl->stacklevel = fs->stacklevel;
+static void enterblock (FuncState *fs, BlockCnt *bl, int isbreakable) {
   bl->breaklist = NO_JUMP;
+  bl->isbreakable = isbreakable;
+  bl->nactvar = fs->nactvar;
+  bl->upval = 0;
   bl->previous = fs->bl;
   fs->bl = bl;
+  lua_assert(fs->freereg == fs->nactvar);
 }
 
 
-static void leavebreak (FuncState *fs, Breaklabel *bl) {
+static void leaveblock (FuncState *fs) {
+  BlockCnt *bl = fs->bl;
   fs->bl = bl->previous;
-  LUA_ASSERT(bl->stacklevel == fs->stacklevel, "wrong levels");
-  luaK_patchlist(fs, bl->breaklist, luaK_getlabel(fs));
+  removevars(fs->ls, bl->nactvar);
+  if (bl->upval)
+    luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
+  lua_assert(bl->nactvar == fs->nactvar);
+  fs->freereg = fs->nactvar;  /* free registers */
+  luaK_patchtohere(fs, bl->breaklist);
 }
 
 
-static void pushclosure (LexState *ls, FuncState *func) {
+static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
   FuncState *fs = ls->fs;
   Proto *f = fs->f;
   int i;
-  for (i=0; i<func->nupvalues; i++)
-    luaK_tostack(ls, &func->upvalues[i], 1);
-  luaM_growvector(ls->L, f->kproto, f->nkproto, 1, Proto *,
-                  "constant table overflow", MAXARG_A);
-  f->kproto[f->nkproto++] = func->f;
-  luaK_code2(fs, OP_CLOSURE, f->nkproto-1, func->nupvalues);
+  luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
+                  MAXARG_Bx, "constant table overflow");
+  f->p[fs->np++] = func->f;
+  init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
+  for (i=0; i<func->f->nups; i++) {
+    OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
+    luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
+  }
 }
 
 
 static void open_func (LexState *ls, FuncState *fs) {
   Proto *f = luaF_newproto(ls->L);
+  fs->f = f;
   fs->prev = ls->fs;  /* linked list of funcstates */
   fs->ls = ls;
   fs->L = ls->L;
   ls->fs = fs;
-  fs->stacklevel = 0;
-  fs->nactloc = 0;
-  fs->nupvalues = 0;
-  fs->bl = NULL;
-  fs->f = f;
-  f->source = ls->source;
   fs->pc = 0;
   fs->lasttarget = 0;
-  fs->lastline = 0;
-  fs->jlt = NO_JUMP;
-  f->code = NULL;
-  f->maxstacksize = 0;
-  f->numparams = 0;  /* default for main chunk */
-  f->is_vararg = 0;  /* default for main chunk */
+  fs->jpc = NO_JUMP;
+  fs->freereg = 0;
+  fs->nk = 0;
+  fs->h = luaH_new(ls->L, 0, 0);
+  fs->np = 0;
+  fs->nlocvars = 0;
+  fs->nactvar = 0;
+  fs->bl = NULL;
+  f->source = ls->source;
+  f->maxstacksize = 2;  /* registers 0/1 are always valid */
 }
 
 
@@ -328,33 +343,40 @@ static void close_func (LexState *ls) {
   lua_State *L = ls->L;
   FuncState *fs = ls->fs;
   Proto *f = fs->f;
-  luaK_code0(fs, OP_END);
-  luaK_getlabel(fs);  /* close eventual list of pending jumps */
-  luaM_reallocvector(L, f->code, fs->pc, Instruction);
-  luaM_reallocvector(L, f->kstr, f->nkstr, TString *);
-  luaM_reallocvector(L, f->knum, f->nknum, Number);
-  luaM_reallocvector(L, f->kproto, f->nkproto, Proto *);
-  removelocalvars(ls, fs->nactloc);
-  luaM_reallocvector(L, f->locvars, f->nlocvars, LocVar);
-  luaM_reallocvector(L, f->lineinfo, f->nlineinfo+1, int);
-  f->lineinfo[f->nlineinfo++] = MAX_INT;  /* end flag */
-  luaF_protook(L, f, fs->pc);  /* proto is ok now */
+  removevars(ls, 0);
+  luaK_codeABC(fs, OP_RETURN, 0, 1, 0);  /* final return */
+  luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
+  f->sizecode = fs->pc;
+  luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
+  f->sizelineinfo = fs->pc;
+  luaM_reallocvector(L, f->k, f->sizek, fs->nk, TObject);
+  f->sizek = fs->nk;
+  luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
+  f->sizep = fs->np;
+  luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
+  f->sizelocvars = fs->nlocvars;
+  luaM_reallocvector(L, f->upvalues, f->sizeupvalues, f->nups, TString *);
+  f->sizeupvalues = f->nups;
+  lua_assert(luaG_checkcode(f));
+  lua_assert(fs->bl == NULL);
   ls->fs = fs->prev;
-  LUA_ASSERT(fs->bl == NULL, "wrong list end");
 }
 
 
-Proto *luaY_parser (lua_State *L, ZIO *z) {
+Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff) {
   struct LexState lexstate;
   struct FuncState funcstate;
+  lexstate.buff = buff;
+  lexstate.nestlevel = 0;
   luaX_setinput(L, &lexstate, z, luaS_new(L, zname(z)));
   open_func(&lexstate, &funcstate);
   next(&lexstate);  /* read first token */
   chunk(&lexstate);
   check_condition(&lexstate, (lexstate.t.token == TK_EOS), "<eof> expected");
   close_func(&lexstate);
-  LUA_ASSERT(funcstate.prev == NULL, "wrong list end");
-  LUA_ASSERT(funcstate.nupvalues == 0, "no upvalues in main");
+  lua_assert(funcstate.prev == NULL);
+  lua_assert(funcstate.f->nups == 0);
+  lua_assert(lexstate.nestlevel == 0);
   return funcstate.f;
 }
 
@@ -365,235 +387,239 @@ Proto *luaY_parser (lua_State *L, ZIO *z) {
 /*============================================================*/
 
 
-static int explist1 (LexState *ls) {
-  /* explist1 -> expr { ',' expr } */
-  int n = 1;  /* at least one expression */
-  expdesc v;
-  expr(ls, &v);
-  while (ls->t.token == ',') {
-    luaK_tostack(ls, &v, 1);  /* gets only 1 value from previous expression */
-    next(ls);  /* skip comma */
-    expr(ls, &v);
-    n++;
-  }
-  luaK_tostack(ls, &v, 0);  /* keep open number of values of last expression */
-  return n;
+static void luaY_field (LexState *ls, expdesc *v) {
+  /* field -> ['.' | ':'] NAME */
+  FuncState *fs = ls->fs;
+  expdesc key;
+  luaK_exp2anyreg(fs, v);
+  next(ls);  /* skip the dot or colon */
+  checkname(ls, &key);
+  luaK_indexed(fs, v, &key);
 }
 
 
-static void funcargs (LexState *ls, int slf) {
+static void luaY_index (LexState *ls, expdesc *v) {
+  /* index -> '[' expr ']' */
+  next(ls);  /* skip the '[' */
+  expr(ls, v);
+  luaK_exp2val(ls->fs, v);
+  check(ls, ']');
+}
+
+
+/*
+** {======================================================================
+** Rules for Constructors
+** =======================================================================
+*/
+
+
+struct ConsControl {
+  expdesc v;  /* last list item read */
+  expdesc *t;  /* table descriptor */
+  int nh;  /* total number of `record' elements */
+  int na;  /* total number of array elements */
+  int tostore;  /* number of array elements pending to be stored */
+};
+
+
+static void recfield (LexState *ls, struct ConsControl *cc) {
+  /* recfield -> (NAME | `['exp1`]') = exp1 */
   FuncState *fs = ls->fs;
-  int slevel = fs->stacklevel - slf - 1;  /* where is func in the stack */
-  switch (ls->t.token) {
-    case '(': {  /* funcargs -> '(' [ explist1 ] ')' */
-      int line = ls->linenumber;
-      int nargs = 0;
-      next(ls);
-      if (ls->t.token != ')')  /* arg list not empty? */
-        nargs = explist1(ls);
-      check_match(ls, ')', '(', line);
-#ifdef LUA_COMPAT_ARGRET
-      if (nargs > 0)  /* arg list is not empty? */
-        luaK_setcallreturns(fs, 1);  /* last call returns only 1 value */
-#else
-      UNUSED(nargs);  /* to avoid warnings */
-#endif
-      break;
-    }
-    case '{': {  /* funcargs -> constructor */
-      constructor(ls);
-      break;
-    }
-    case TK_STRING: {  /* funcargs -> STRING */
-      code_string(ls, ls->t.seminfo.ts);  /* must use `seminfo' before `next' */
-      next(ls);
-      break;
-    }
-    default: {
-      luaK_error(ls, "function arguments expected");
-      break;
-    }
+  int reg = ls->fs->freereg;
+  expdesc key, val;
+  if (ls->t.token == TK_NAME) {
+    luaX_checklimit(ls, cc->nh, MAX_INT, "items in a constructor");
+    cc->nh++;
+    checkname(ls, &key);
+  }
+  else  /* ls->t.token == '[' */
+    luaY_index(ls, &key);
+  check(ls, '=');
+  luaK_exp2RK(fs, &key);
+  expr(ls, &val);
+  luaK_codeABC(fs, OP_SETTABLE, cc->t->info, luaK_exp2RK(fs, &key),
+                                             luaK_exp2RK(fs, &val));
+  fs->freereg = reg;  /* free registers */
+}
+
+
+static void closelistfield (FuncState *fs, struct ConsControl *cc) {
+  if (cc->v.k == VVOID) return;  /* there is no list item */
+  luaK_exp2nextreg(fs, &cc->v);
+  cc->v.k = VVOID;
+  if (cc->tostore == LFIELDS_PER_FLUSH) {
+    luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1);  /* flush */
+    cc->tostore = 0;  /* no more items pending */
+    fs->freereg = cc->t->info + 1;  /* free registers */
   }
-  fs->stacklevel = slevel;  /* call will remove function and arguments */
-  luaK_code2(fs, OP_CALL, slevel, MULT_RET);
 }
 
 
-static void var_or_func_tail (LexState *ls, expdesc *v) {
-  for (;;) {
-    switch (ls->t.token) {
-      case '.': {  /* var_or_func_tail -> '.' NAME */
-        next(ls);
-        luaK_tostack(ls, v, 1);  /* `v' must be on stack */
-        luaK_kstr(ls, checkname(ls));
-        v->k = VINDEXED;
-        break;
-      }
-      case '[': {  /* var_or_func_tail -> '[' exp1 ']' */
-        next(ls);
-        luaK_tostack(ls, v, 1);  /* `v' must be on stack */
-        v->k = VINDEXED;
-        exp1(ls);
-        check(ls, ']');
+static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
+  if (cc->tostore == 0) return;
+  if (cc->v.k == VCALL) {
+    luaK_setcallreturns(fs, &cc->v, LUA_MULTRET);
+    luaK_codeABx(fs, OP_SETLISTO, cc->t->info, cc->na-1);
+  }
+  else {
+    if (cc->v.k != VVOID)
+      luaK_exp2nextreg(fs, &cc->v);
+    luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1);
+  }
+  fs->freereg = cc->t->info + 1;  /* free registers */
+}
+
+
+static void listfield (LexState *ls, struct ConsControl *cc) {
+  expr(ls, &cc->v);
+  luaX_checklimit(ls, cc->na, MAXARG_Bx, "items in a constructor");
+  cc->na++;
+  cc->tostore++;
+}
+
+
+static void constructor (LexState *ls, expdesc *t) {
+  /* constructor -> ?? */
+  FuncState *fs = ls->fs;
+  int line = ls->linenumber;
+  int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
+  struct ConsControl cc;
+  cc.na = cc.nh = cc.tostore = 0;
+  cc.t = t;
+  init_exp(t, VRELOCABLE, pc);
+  init_exp(&cc.v, VVOID, 0);  /* no value (yet) */
+  luaK_exp2nextreg(ls->fs, t);  /* fix it at stack top (for gc) */
+  check(ls, '{');
+  do {
+    lua_assert(cc.v.k == VVOID || cc.tostore > 0);
+    testnext(ls, ';');  /* compatibility only */
+    if (ls->t.token == '}') break;
+    closelistfield(fs, &cc);
+    switch(ls->t.token) {
+      case TK_NAME: {  /* may be listfields or recfields */
+        lookahead(ls);
+        if (ls->lookahead.token != '=')  /* expression? */
+          listfield(ls, &cc);
+        else
+          recfield(ls, &cc);
         break;
       }
-      case ':': {  /* var_or_func_tail -> ':' NAME funcargs */
-        int name;
-        next(ls);
-        name = checkname(ls);
-        luaK_tostack(ls, v, 1);  /* `v' must be on stack */
-        luaK_code1(ls->fs, OP_PUSHSELF, name);
-        funcargs(ls, 1);
-        v->k = VEXP;
-        v->u.l.t = v->u.l.f = NO_JUMP;
+      case '[': {  /* constructor_item -> recfield */
+        recfield(ls, &cc);
         break;
       }
-      case '(': case TK_STRING: case '{': {  /* var_or_func_tail -> funcargs */
-        luaK_tostack(ls, v, 1);  /* `v' must be on stack */
-        funcargs(ls, 0);
-        v->k = VEXP;
-        v->u.l.t = v->u.l.f = NO_JUMP;
+      default: {  /* constructor_part -> listfield */
+        listfield(ls, &cc);
         break;
       }
-      default: return;  /* should be follow... */
     }
-  }
-}
-
-
-static void var_or_func (LexState *ls, expdesc *v) {
-  /* var_or_func -> ['%'] NAME var_or_func_tail */
-  if (optional(ls, '%')) {  /* upvalue? */
-    pushupvalue(ls, str_checkname(ls));
-    v->k = VEXP;
-    v->u.l.t = v->u.l.f = NO_JUMP;
-  }
-  else  /* variable name */
-    singlevar(ls, str_checkname(ls), v);
-  var_or_func_tail(ls, v);
+  } while (testnext(ls, ',') || testnext(ls, ';'));
+  check_match(ls, '}', '{', line);
+  lastlistfield(fs, &cc);
+  SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
+  SETARG_C(fs->f->code[pc], luaO_log2(cc.nh)+1);  /* set initial table size */
 }
 
+/* }====================================================================== */
 
 
-/*
-** {======================================================================
-** Rules for Constructors
-** =======================================================================
-*/
-
 
-static void recfield (LexState *ls) {
-  /* recfield -> (NAME | '['exp1']') = exp1 */
-  switch (ls->t.token) {
-    case TK_NAME: {
-      luaK_kstr(ls, checkname(ls));
-      break;
-    }
-    case '[': {
-      next(ls);
-      exp1(ls);
-      check(ls, ']');
-      break;
-    }
-    default: luaK_error(ls, "<name> or `[' expected");
+static void parlist (LexState *ls) {
+  /* parlist -> [ param { `,' param } ] */
+  int nparams = 0;
+  int dots = 0;
+  if (ls->t.token != ')') {  /* is `parlist' not empty? */
+    do {
+      switch (ls->t.token) {
+        case TK_DOTS: dots = 1; next(ls); break;
+        case TK_NAME: new_localvar(ls, str_checkname(ls), nparams++); break;
+        default: luaX_syntaxerror(ls, "<name> or `...' expected");
+      }
+    } while (!dots && testnext(ls, ','));
   }
-  check(ls, '=');
-  exp1(ls);
+  code_params(ls, nparams, dots);
 }
 
 
-static int recfields (LexState *ls) {
-  /* recfields -> recfield { ',' recfield } [','] */
-  FuncState *fs = ls->fs;
-  int n = 1;  /* at least one element */
-  recfield(ls);
-  while (ls->t.token == ',') {
-    next(ls);
-    if (ls->t.token == ';' || ls->t.token == '}')
-      break;
-    recfield(ls);
-    n++;
-    if (n%RFIELDS_PER_FLUSH == 0)
-      luaK_code1(fs, OP_SETMAP, RFIELDS_PER_FLUSH);
-  }
-  luaK_code1(fs, OP_SETMAP, n%RFIELDS_PER_FLUSH);
-  return n;
+static void body (LexState *ls, expdesc *e, int needself, int line) {
+  /* body ->  `(' parlist `)' chunk END */
+  FuncState new_fs;
+  open_func(ls, &new_fs);
+  new_fs.f->lineDefined = line;
+  check(ls, '(');
+  if (needself)
+    create_local(ls, "self");
+  parlist(ls);
+  check(ls, ')');
+  chunk(ls);
+  check_match(ls, TK_END, TK_FUNCTION, line);
+  close_func(ls);
+  pushclosure(ls, &new_fs, e);
 }
 
 
-static int listfields (LexState *ls) {
-  /* listfields -> exp1 { ',' exp1 } [','] */
-  FuncState *fs = ls->fs;
-  int n = 1;  /* at least one element */
-  exp1(ls);
-  while (ls->t.token == ',') {
-    next(ls);
-    if (ls->t.token == ';' || ls->t.token == '}')
-      break;
-    exp1(ls);
+static int explist1 (LexState *ls, expdesc *v) {
+  /* explist1 -> expr { `,' expr } */
+  int n = 1;  /* at least one expression */
+  expr(ls, v);
+  while (testnext(ls, ',')) {
+    luaK_exp2nextreg(ls->fs, v);
+    expr(ls, v);
     n++;
-    luaX_checklimit(ls, n/LFIELDS_PER_FLUSH, MAXARG_A,
-               "`item groups' in a list initializer");
-    if (n%LFIELDS_PER_FLUSH == 0)
-      luaK_code2(fs, OP_SETLIST, n/LFIELDS_PER_FLUSH - 1, LFIELDS_PER_FLUSH);
   }
-  luaK_code2(fs, OP_SETLIST, n/LFIELDS_PER_FLUSH, n%LFIELDS_PER_FLUSH);
   return n;
 }
 
 
-
-static void constructor_part (LexState *ls, Constdesc *cd) {
+static void funcargs (LexState *ls, expdesc *f) {
+  FuncState *fs = ls->fs;
+  expdesc args;
+  int base, nparams;
+  int line = ls->linenumber;
   switch (ls->t.token) {
-    case ';': case '}': {  /* constructor_part -> empty */
-      cd->n = 0;
-      cd->k = ls->t.token;
+    case '(': {  /* funcargs -> `(' [ explist1 ] `)' */
+      if (line != ls->lastline)
+        luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)");
+      next(ls);
+      if (ls->t.token == ')')  /* arg list is empty? */
+        args.k = VVOID;
+      else {
+        explist1(ls, &args);
+        luaK_setcallreturns(fs, &args, LUA_MULTRET);
+      }
+      check_match(ls, ')', '(', line);
       break;
     }
-    case TK_NAME: {  /* may be listfields or recfields */
-      lookahead(ls);
-      if (ls->lookahead.token != '=')  /* expression? */
-        goto case_default;
-      /* else go through to recfields */
-    }
-    case '[': {  /* constructor_part -> recfields */
-      cd->n = recfields(ls);
-      cd->k = 1;  /* record */
+    case '{': {  /* funcargs -> constructor */
+      constructor(ls, &args);
       break;
     }
-    default: {  /* constructor_part -> listfields */
-    case_default:
-      cd->n = listfields(ls);
-      cd->k = 0;  /* list */
+    case TK_STRING: {  /* funcargs -> STRING */
+      codestring(ls, &args, ls->t.seminfo.ts);
+      next(ls);  /* must use `seminfo' before `next' */
       break;
     }
+    default: {
+      luaX_syntaxerror(ls, "function arguments expected");
+      return;
+    }
   }
-}
-
-
-static void constructor (LexState *ls) {
-  /* constructor -> '{' constructor_part [';' constructor_part] '}' */
-  FuncState *fs = ls->fs;
-  int line = ls->linenumber;
-  int pc = luaK_code1(fs, OP_CREATETABLE, 0);
-  int nelems;
-  Constdesc cd;
-  check(ls, '{');
-  constructor_part(ls, &cd);
-  nelems = cd.n;
-  if (optional(ls, ';')) {
-    Constdesc other_cd;
-    constructor_part(ls, &other_cd);
-    check_condition(ls, (cd.k != other_cd.k), "invalid constructor syntax");
-    nelems += other_cd.n;
+  lua_assert(f->k == VNONRELOC);
+  base = f->info;  /* base register for call */
+  if (args.k == VCALL)
+    nparams = LUA_MULTRET;  /* open call */
+  else {
+    if (args.k != VVOID)
+      luaK_exp2nextreg(fs, &args);  /* close last argument */
+    nparams = fs->freereg - (base+1);
   }
-  check_match(ls, '}', '{', line);
-  luaX_checklimit(ls, nelems, MAXARG_U, "elements in a table constructor");
-  SETARG_U(fs->f->code[pc], nelems);  /* set initial table size */
+  init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
+  luaK_fixline(fs, line);
+  fs->freereg = base+1;  /* call remove function and arguments and leaves
+                            (unless changed) one result */
 }
 
-/* }====================================================================== */
-
 
 
 
@@ -604,58 +630,121 @@ static void constructor (LexState *ls) {
 */
 
 
-static void simpleexp (LexState *ls, expdesc *v) {
-  FuncState *fs = ls->fs;
+static void prefixexp (LexState *ls, expdesc *v) {
+  /* prefixexp -> NAME | '(' expr ')' */
   switch (ls->t.token) {
-    case TK_NUMBER: {  /* simpleexp -> NUMBER */
-      Number r = ls->t.seminfo.r;
+    case '(': {
+      int line = ls->linenumber;
       next(ls);
-      luaK_number(fs, r);
+      expr(ls, v);
+      check_match(ls, ')', '(', line);
+      luaK_dischargevars(ls->fs, v);
+      return;
+    }
+    case TK_NAME: {
+      singlevar(ls, v, 1);
+      return;
+    }
+#ifdef LUA_COMPATUPSYNTAX
+    case '%': {  /* for compatibility only */
+      TString *varname;
+      int line = ls->linenumber;
+      next(ls);  /* skip `%' */
+      varname = singlevar(ls, v, 1);
+      if (v->k != VUPVAL)
+        luaX_errorline(ls, "global upvalues are obsolete",
+                           getstr(varname), line);
+      return;
+    }
+#endif
+    default: {
+      luaX_syntaxerror(ls, "unexpected symbol");
+      return;
+    }
+  }
+}
+
+
+static void primaryexp (LexState *ls, expdesc *v) {
+  /* primaryexp ->
+        prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
+  FuncState *fs = ls->fs;
+  prefixexp(ls, v);
+  for (;;) {
+    switch (ls->t.token) {
+      case '.': {  /* field */
+        luaY_field(ls, v);
+        break;
+      }
+      case '[': {  /* `[' exp1 `]' */
+        expdesc key;
+        luaK_exp2anyreg(fs, v);
+        luaY_index(ls, &key);
+        luaK_indexed(fs, v, &key);
+        break;
+      }
+      case ':': {  /* `:' NAME funcargs */
+        expdesc key;
+        next(ls);
+        checkname(ls, &key);
+        luaK_self(fs, v, &key);
+        funcargs(ls, v);
+        break;
+      }
+      case '(': case TK_STRING: case '{': {  /* funcargs */
+        luaK_exp2nextreg(fs, v);
+        funcargs(ls, v);
+        break;
+      }
+      default: return;
+    }
+  }
+}
+
+
+static void simpleexp (LexState *ls, expdesc *v) {
+  /* simpleexp -> NUMBER | STRING | NIL | constructor | FUNCTION body
+               | primaryexp */
+  switch (ls->t.token) {
+    case TK_NUMBER: {
+      init_exp(v, VK, luaK_numberK(ls->fs, ls->t.seminfo.r));
+      next(ls);  /* must use `seminfo' before `next' */
       break;
     }
-    case TK_STRING: {  /* simpleexp -> STRING */
-      code_string(ls, ls->t.seminfo.ts);  /* must use `seminfo' before `next' */
-      next(ls);
+    case TK_STRING: {
+      codestring(ls, v, ls->t.seminfo.ts);
+      next(ls);  /* must use `seminfo' before `next' */
       break;
     }
-    case TK_NIL: {  /* simpleexp -> NIL */
-      luaK_adjuststack(fs, -1);
+    case TK_NIL: {
+      init_exp(v, VNIL, 0);
       next(ls);
       break;
     }
-    case '{': {  /* simpleexp -> constructor */
-      constructor(ls);
+    case TK_TRUE: {
+      init_exp(v, VTRUE, 0);
+      next(ls);
       break;
     }
-    case TK_FUNCTION: {  /* simpleexp -> FUNCTION body */
+    case TK_FALSE: {
+      init_exp(v, VFALSE, 0);
       next(ls);
-      body(ls, 0, ls->linenumber);
       break;
     }
-    case '(': {  /* simpleexp -> '(' expr ')' */
-      next(ls);
-      expr(ls, v);
-      check(ls, ')');
-      return;
+    case '{': {  /* constructor */
+      constructor(ls, v);
+      break;
     }
-    case TK_NAME: case '%': {
-      var_or_func(ls, v);
-      return;
+    case TK_FUNCTION: {
+      next(ls);
+      body(ls, v, 0, ls->linenumber);
+      break;
     }
     default: {
-      luaK_error(ls, "<expression> expected");
-      return;
+      primaryexp(ls, v);
+      break;
     }
   }
-  v->k = VEXP;
-  v->u.l.t = v->u.l.f = NO_JUMP;
-}
-
-
-static void exp1 (LexState *ls) {
-  expdesc v;
-  expr(ls, &v);
-  luaK_tostack(ls, &v, 1);
 }
 
 
@@ -690,17 +779,17 @@ static BinOpr getbinopr (int op) {
 
 
 static const struct {
-  char left;  /* left priority for each binary operator */
-  char right; /* right priority */
+  lu_byte left;  /* left priority for each binary operator */
+  lu_byte right; /* right priority */
 } priority[] = {  /* ORDER OPR */
-   {5, 5}, {5, 5}, {6, 6}, {6, 6},  /* arithmetic */
-   {9, 8}, {4, 3},                  /* power and concat (right associative) */
-   {2, 2}, {2, 2},                  /* equality */
-   {2, 2}, {2, 2}, {2, 2}, {2, 2},  /* order */
-   {1, 1}, {1, 1}                   /* logical */
+   {6, 6}, {6, 6}, {7, 7}, {7, 7},  /* arithmetic */
+   {10, 9}, {5, 4},                 /* power and concat (right associative) */
+   {3, 3}, {3, 3},                  /* equality */
+   {3, 3}, {3, 3}, {3, 3}, {3, 3},  /* order */
+   {2, 2}, {1, 1}                   /* logical (and/or) */
 };
 
-#define UNARY_PRIORITY	7  /* priority for unary operators */
+#define UNARY_PRIORITY	8  /* priority for unary operators */
 
 
 /*
@@ -709,25 +798,28 @@ static const struct {
 */
 static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
   BinOpr op;
-  UnOpr uop = getunopr(ls->t.token);
+  UnOpr uop;
+  enterlevel(ls);
+  uop = getunopr(ls->t.token);
   if (uop != OPR_NOUNOPR) {
     next(ls);
     subexpr(ls, v, UNARY_PRIORITY);
-    luaK_prefix(ls, uop, v);
+    luaK_prefix(ls->fs, uop, v);
   }
   else simpleexp(ls, v);
   /* expand while operators have priorities higher than `limit' */
   op = getbinopr(ls->t.token);
-  while (op != OPR_NOBINOPR && priority[op].left > limit) {
+  while (op != OPR_NOBINOPR && cast(int, priority[op].left) > limit) {
     expdesc v2;
     BinOpr nextop;
     next(ls);
-    luaK_infix(ls, op, v);
+    luaK_infix(ls->fs, op, v);
     /* read sub-expression with higher priority */
-    nextop = subexpr(ls, &v2, priority[op].right);
-    luaK_posfix(ls, op, v, &v2);
+    nextop = subexpr(ls, &v2, cast(int, priority[op].right));
+    luaK_posfix(ls->fs, op, v, &v2);
     op = nextop;
   }
+  leavelevel(ls);
   return op;  /* return first untreated operator */
 }
 
@@ -739,6 +831,7 @@ static void expr (LexState *ls, expdesc *v) {
 /* }==================================================================== */
 
 
+
 /*
 ** {======================================================================
 ** Rules for Statements
@@ -759,61 +852,151 @@ static int block_follow (int token) {
 static void block (LexState *ls) {
   /* block -> chunk */
   FuncState *fs = ls->fs;
-  int nactloc = fs->nactloc;
+  BlockCnt bl;
+  enterblock(fs, &bl, 0);
   chunk(ls);
-  luaK_adjuststack(fs, fs->nactloc - nactloc);  /* remove local variables */
-  removelocalvars(ls, fs->nactloc - nactloc);
+  lua_assert(bl.breaklist == NO_JUMP);
+  leaveblock(fs);
 }
 
 
-static int assignment (LexState *ls, expdesc *v, int nvars) {
-  int left = 0;  /* number of values left in the stack after assignment */
-  luaX_checklimit(ls, nvars, MAXVARSLH, "variables in a multiple assignment");
-  if (ls->t.token == ',') {  /* assignment -> ',' NAME assignment */
-    expdesc nv;
-    next(ls);
-    var_or_func(ls, &nv);
-    check_condition(ls, (nv.k != VEXP), "syntax error");
-    left = assignment(ls, &nv, nvars+1);
+/*
+** structure to chain all variables in the left-hand side of an
+** assignment
+*/
+struct LHS_assign {
+  struct LHS_assign *prev;
+  expdesc v;  /* variable (global, local, upvalue, or indexed) */
+};
+
+
+/*
+** check whether, in an assignment to a local variable, the local variable
+** is needed in a previous assignment (to a table). If so, save original
+** local value in a safe place and use this safe copy in the previous
+** assignment.
+*/
+static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
+  FuncState *fs = ls->fs;
+  int extra = fs->freereg;  /* eventual position to save local variable */
+  int conflict = 0;
+  for (; lh; lh = lh->prev) {
+    if (lh->v.k == VINDEXED) {
+      if (lh->v.info == v->info) {  /* conflict? */
+        conflict = 1;
+        lh->v.info = extra;  /* previous assignment will use safe copy */
+      }
+      if (lh->v.aux == v->info) {  /* conflict? */
+        conflict = 1;
+        lh->v.aux = extra;  /* previous assignment will use safe copy */
+      }
+    }
+  }
+  if (conflict) {
+    luaK_codeABC(fs, OP_MOVE, fs->freereg, v->info, 0);  /* make copy */
+    luaK_reserveregs(fs, 1);
   }
-  else {  /* assignment -> '=' explist1 */
+}
+
+
+static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
+  expdesc e;
+  check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
+                      "syntax error");
+  if (testnext(ls, ',')) {  /* assignment -> `,' primaryexp assignment */
+    struct LHS_assign nv;
+    nv.prev = lh;
+    primaryexp(ls, &nv.v);
+    if (nv.v.k == VLOCAL)
+      check_conflict(ls, lh, &nv.v);
+    assignment(ls, &nv, nvars+1);
+  }
+  else {  /* assignment -> `=' explist1 */
     int nexps;
     check(ls, '=');
-    nexps = explist1(ls);
-    adjust_mult_assign(ls, nvars, nexps);
-  }
-  if (v->k != VINDEXED)
-    luaK_storevar(ls, v);
-  else {  /* there may be garbage between table-index and value */
-    luaK_code2(ls->fs, OP_SETTABLE, left+nvars+2, 1);
-    left += 2;
+    nexps = explist1(ls, &e);
+    if (nexps != nvars) {
+      adjust_assign(ls, nvars, nexps, &e);
+      if (nexps > nvars)
+        ls->fs->freereg -= nexps - nvars;  /* remove extra values */
+    }
+    else {
+      luaK_setcallreturns(ls->fs, &e, 1);  /* close last expression */
+      luaK_storevar(ls->fs, &lh->v, &e);
+      return;  /* avoid default */
+    }
   }
-  return left;
+  init_exp(&e, VNONRELOC, ls->fs->freereg-1);  /* default assignment */
+  luaK_storevar(ls->fs, &lh->v, &e);
 }
 
 
 static void cond (LexState *ls, expdesc *v) {
   /* cond -> exp */
   expr(ls, v);  /* read condition */
-  luaK_goiftrue(ls->fs, v, 0);
+  if (v->k == VNIL) v->k = VFALSE;  /* `falses' are all equal here */
+  luaK_goiftrue(ls->fs, v);
+  luaK_patchtohere(ls->fs, v->t);
 }
 
 
+/*
+** The while statement optimizes its code by coding the condition
+** after its body (and thus avoiding one jump in the loop).
+*/
+
+/*
+** maximum size of expressions for optimizing `while' code
+*/
+#ifndef MAXEXPWHILE
+#define MAXEXPWHILE	100
+#endif
+
+/*
+** the call `luaK_goiffalse' may grow the size of an expression by
+** at most this:
+*/
+#define EXTRAEXP	5
+
 static void whilestat (LexState *ls, int line) {
   /* whilestat -> WHILE cond DO block END */
+  Instruction codeexp[MAXEXPWHILE + EXTRAEXP];
+  int lineexp;
+  int i;
+  int sizeexp;
   FuncState *fs = ls->fs;
-  int while_init = luaK_getlabel(fs);
+  int whileinit, blockinit, expinit;
   expdesc v;
-  Breaklabel bl;
-  enterbreak(fs, &bl);
-  next(ls);
-  cond(ls, &v);
+  BlockCnt bl;
+  next(ls);  /* skip WHILE */
+  whileinit = luaK_jump(fs);  /* jump to condition (which will be moved) */
+  expinit = luaK_getlabel(fs);
+  expr(ls, &v);  /* parse condition */
+  if (v.k == VK) v.k = VTRUE;  /* `trues' are all equal here */
+  lineexp = ls->linenumber;
+  luaK_goiffalse(fs, &v);
+  luaK_concat(fs, &v.f, fs->jpc);
+  fs->jpc = NO_JUMP;
+  sizeexp = fs->pc - expinit;  /* size of expression code */
+  if (sizeexp > MAXEXPWHILE) 
+    luaX_syntaxerror(ls, "`while' condition too complex");
+  for (i = 0; i < sizeexp; i++)  /* save `exp' code */
+    codeexp[i] = fs->f->code[expinit + i];
+  fs->pc = expinit;  /* remove `exp' code */
+  enterblock(fs, &bl, 1);
   check(ls, TK_DO);
+  blockinit = luaK_getlabel(fs);
   block(ls);
-  luaK_patchlist(fs, luaK_jump(fs), while_init);
-  luaK_patchlist(fs, v.u.l.f, luaK_getlabel(fs));
+  luaK_patchtohere(fs, whileinit);  /* initial jump jumps to here */
+  /* move `exp' back to code */
+  if (v.t != NO_JUMP) v.t += fs->pc - expinit;
+  if (v.f != NO_JUMP) v.f += fs->pc - expinit;
+  for (i=0; i<sizeexp; i++)
+    luaK_code(fs, codeexp[i], lineexp);
   check_match(ls, TK_END, TK_WHILE, line);
-  leavebreak(fs, &bl);
+  leaveblock(fs);
+  luaK_patchlist(fs, v.t, blockinit);  /* true conditions go back to loop */
+  luaK_patchtohere(fs, v.f);  /* false conditions finish the loop */
 }
 
 
@@ -822,64 +1005,86 @@ static void repeatstat (LexState *ls, int line) {
   FuncState *fs = ls->fs;
   int repeat_init = luaK_getlabel(fs);
   expdesc v;
-  Breaklabel bl;
-  enterbreak(fs, &bl);
+  BlockCnt bl;
+  enterblock(fs, &bl, 1);
   next(ls);
   block(ls);
   check_match(ls, TK_UNTIL, TK_REPEAT, line);
   cond(ls, &v);
-  luaK_patchlist(fs, v.u.l.f, repeat_init);
-  leavebreak(fs, &bl);
+  luaK_patchlist(fs, v.f, repeat_init);
+  leaveblock(fs);
 }
 
 
-static void forbody (LexState *ls, int nvar, OpCode prepfor, OpCode loopfor) {
-  /* forbody -> DO block END */
+static int exp1 (LexState *ls) {
+  expdesc e;
+  int k;
+  expr(ls, &e);
+  k = e.k;
+  luaK_exp2nextreg(ls->fs, &e);
+  return k;
+}
+
+
+static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
+  BlockCnt bl;
   FuncState *fs = ls->fs;
-  int prep = luaK_code1(fs, prepfor, NO_JUMP);
-  int blockinit = luaK_getlabel(fs);
+  int prep, endfor;
+  adjustlocalvars(ls, nvars);  /* scope for all variables */
   check(ls, TK_DO);
-  adjustlocalvars(ls, nvar);  /* scope for control variables */
+  enterblock(fs, &bl, 1);  /* loop block */
+  prep = luaK_getlabel(fs);
   block(ls);
-  luaK_patchlist(fs, luaK_code1(fs, loopfor, NO_JUMP), blockinit);
-  luaK_patchlist(fs, prep, luaK_getlabel(fs));
-  removelocalvars(ls, nvar);
+  luaK_patchtohere(fs, prep-1);
+  endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
+                     luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
+  luaK_fixline(fs, line);  /* pretend that `OP_FOR' starts the loop */
+  luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep);
+  leaveblock(fs);
 }
 
 
-static void fornum (LexState *ls, TString *varname) {
-  /* fornum -> NAME = exp1,exp1[,exp1] forbody */
+static void fornum (LexState *ls, TString *varname, int line) {
+  /* fornum -> NAME = exp1,exp1[,exp1] DO body */
   FuncState *fs = ls->fs;
+  int base = fs->freereg;
+  new_localvar(ls, varname, 0);
+  new_localvarstr(ls, "(for limit)", 1);
+  new_localvarstr(ls, "(for step)", 2);
   check(ls, '=');
   exp1(ls);  /* initial value */
   check(ls, ',');
   exp1(ls);  /* limit */
-  if (optional(ls, ','))
+  if (testnext(ls, ','))
     exp1(ls);  /* optional step */
-  else
-    luaK_code1(fs, OP_PUSHINT, 1);  /* default step */
-  new_localvar(ls, varname, 0);
-  new_localvarstr(ls, "(limit)", 1);
-  new_localvarstr(ls, "(step)", 2);
-  forbody(ls, 3, OP_FORPREP, OP_FORLOOP);
+  else {  /* default step = 1 */
+    luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1));
+    luaK_reserveregs(fs, 1);
+  }
+  luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1);
+  luaK_jump(fs);
+  forbody(ls, base, line, 3, 1);
 }
 
 
 static void forlist (LexState *ls, TString *indexname) {
-  /* forlist -> NAME,NAME IN exp1 forbody */
-  TString *valname;
-  check(ls, ',');
-  valname = str_checkname(ls);
-  /* next test is dirty, but avoids `in' being a reserved word */
-  check_condition(ls,
-       (ls->t.token == TK_NAME && ls->t.seminfo.ts == luaS_new(ls->L, "in")),
-       "`in' expected");
-  next(ls);  /* skip `in' */
-  exp1(ls);  /* table */
-  new_localvarstr(ls, "(table)", 0);
-  new_localvar(ls, indexname, 1);
-  new_localvar(ls, valname, 2);
-  forbody(ls, 3, OP_LFORPREP, OP_LFORLOOP);
+  /* forlist -> NAME {,NAME} IN explist1 DO body */
+  FuncState *fs = ls->fs;
+  expdesc e;
+  int nvars = 0;
+  int line;
+  int base = fs->freereg;
+  new_localvarstr(ls, "(for generator)", nvars++);
+  new_localvarstr(ls, "(for state)", nvars++);
+  new_localvar(ls, indexname, nvars++);
+  while (testnext(ls, ','))
+    new_localvar(ls, str_checkname(ls), nvars++);
+  check(ls, TK_IN);
+  line = ls->linenumber;
+  adjust_assign(ls, nvars, explist1(ls, &e), &e);
+  luaK_checkstack(fs, 3);  /* extra space to call generator */
+  luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP);
+  forbody(ls, base, line, nvars, 0);
 }
 
 
@@ -887,17 +1092,17 @@ static void forstat (LexState *ls, int line) {
   /* forstat -> fornum | forlist */
   FuncState *fs = ls->fs;
   TString *varname;
-  Breaklabel bl;
-  enterbreak(fs, &bl);
+  BlockCnt bl;
+  enterblock(fs, &bl, 0);  /* block to control variable scope */
   next(ls);  /* skip `for' */
   varname = str_checkname(ls);  /* first variable name */
   switch (ls->t.token) {
-    case '=': fornum(ls, varname); break;
-    case ',': forlist(ls, varname); break;
-    default: luaK_error(ls, "`=' or `,' expected");
+    case '=': fornum(ls, varname, line); break;
+    case ',': case TK_IN: forlist(ls, varname); break;
+    default: luaX_syntaxerror(ls, "`=' or `in' expected");
   }
   check_match(ls, TK_END, TK_FOR, line);
-  leavebreak(fs, &bl);
+  leaveblock(fs);
 }
 
 
@@ -918,49 +1123,60 @@ static void ifstat (LexState *ls, int line) {
   test_then_block(ls, &v);  /* IF cond THEN block */
   while (ls->t.token == TK_ELSEIF) {
     luaK_concat(fs, &escapelist, luaK_jump(fs));
-    luaK_patchlist(fs, v.u.l.f, luaK_getlabel(fs));
+    luaK_patchtohere(fs, v.f);
     test_then_block(ls, &v);  /* ELSEIF cond THEN block */
   }
   if (ls->t.token == TK_ELSE) {
     luaK_concat(fs, &escapelist, luaK_jump(fs));
-    luaK_patchlist(fs, v.u.l.f, luaK_getlabel(fs));
-    next(ls);  /* skip ELSE */
+    luaK_patchtohere(fs, v.f);
+    next(ls);  /* skip ELSE (after patch, for correct line info) */
     block(ls);  /* `else' part */
   }
   else
-    luaK_concat(fs, &escapelist, v.u.l.f);
-  luaK_patchlist(fs, escapelist, luaK_getlabel(fs));
+    luaK_concat(fs, &escapelist, v.f);
+  luaK_patchtohere(fs, escapelist);
   check_match(ls, TK_END, TK_IF, line);
 }
 
 
+static void localfunc (LexState *ls) {
+  expdesc v, b;
+  new_localvar(ls, str_checkname(ls), 0);
+  init_exp(&v, VLOCAL, ls->fs->freereg++);
+  adjustlocalvars(ls, 1);
+  body(ls, &b, 0, ls->linenumber);
+  luaK_storevar(ls->fs, &v, &b);
+}
+
+
 static void localstat (LexState *ls) {
-  /* stat -> LOCAL NAME {',' NAME} ['=' explist1] */
+  /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
   int nvars = 0;
   int nexps;
+  expdesc e;
   do {
-    next(ls);  /* skip LOCAL or ',' */
     new_localvar(ls, str_checkname(ls), nvars++);
-  } while (ls->t.token == ',');
-  if (optional(ls, '='))
-    nexps = explist1(ls);
-  else
+  } while (testnext(ls, ','));
+  if (testnext(ls, '='))
+    nexps = explist1(ls, &e);
+  else {
+    e.k = VVOID;
     nexps = 0;
-  adjust_mult_assign(ls, nvars, nexps);
+  }
+  adjust_assign(ls, nvars, nexps, &e);
   adjustlocalvars(ls, nvars);
 }
 
 
 static int funcname (LexState *ls, expdesc *v) {
-  /* funcname -> NAME [':' NAME | '.' NAME] */
+  /* funcname -> NAME {field} [`:' NAME] */
   int needself = 0;
-  singlevar(ls, str_checkname(ls), v);
-  if (ls->t.token == ':' || ls->t.token == '.') {
-    needself = (ls->t.token == ':');
-    next(ls);
-    luaK_tostack(ls, v, 1);
-    luaK_kstr(ls, checkname(ls));
-    v->k = VINDEXED;
+  singlevar(ls, v, 1);
+  while (ls->t.token == '.')
+    luaY_field(ls, v);
+  if (ls->t.token == ':') {
+    needself = 1;
+    luaY_field(ls, v);
   }
   return needself;
 }
@@ -969,26 +1185,26 @@ static int funcname (LexState *ls, expdesc *v) {
 static void funcstat (LexState *ls, int line) {
   /* funcstat -> FUNCTION funcname body */
   int needself;
-  expdesc v;
+  expdesc v, b;
   next(ls);  /* skip FUNCTION */
   needself = funcname(ls, &v);
-  body(ls, needself, line);
-  luaK_storevar(ls, &v);
+  body(ls, &b, needself, line);
+  luaK_storevar(ls->fs, &v, &b);
+  luaK_fixline(ls->fs, line);  /* definition `happens' in the first line */
 }
 
 
-static void namestat (LexState *ls) {
-  /* stat -> func | ['%'] NAME assignment */
+static void exprstat (LexState *ls) {
+  /* stat -> func | assignment */
   FuncState *fs = ls->fs;
-  expdesc v;
-  var_or_func(ls, &v);
-  if (v.k == VEXP) {  /* stat -> func */
-    check_condition(ls, luaK_lastisopen(fs), "syntax error");  /* an upvalue? */
-    luaK_setcallreturns(fs, 0);  /* call statement uses no results */
+  struct LHS_assign v;
+  primaryexp(ls, &v.v);
+  if (v.v.k == VCALL) {  /* stat -> func */
+    luaK_setcallreturns(fs, &v.v, 0);  /* call statement uses no results */
   }
-  else {  /* stat -> ['%'] NAME assignment */
-    int left = assignment(ls, &v, 1);
-    luaK_adjuststack(fs, left);  /* remove eventual garbage left on stack */
+  else {  /* stat -> assignment */
+    v.prev = NULL;
+    assignment(ls, &v, 1);
   }
 }
 
@@ -996,30 +1212,55 @@ static void namestat (LexState *ls) {
 static void retstat (LexState *ls) {
   /* stat -> RETURN explist */
   FuncState *fs = ls->fs;
+  expdesc e;
+  int first, nret;  /* registers with returned values */
   next(ls);  /* skip RETURN */
-  if (!block_follow(ls->t.token) && ls->t.token != ';')
-    explist1(ls);  /* optional return values */
-  luaK_code1(fs, OP_RETURN, ls->fs->nactloc);
-  fs->stacklevel = fs->nactloc;  /* removes all temp values */
+  if (block_follow(ls->t.token) || ls->t.token == ';')
+    first = nret = 0;  /* return no values */
+  else {
+    nret = explist1(ls, &e);  /* optional return values */
+    if (e.k == VCALL) {
+      luaK_setcallreturns(fs, &e, LUA_MULTRET);
+      if (nret == 1) {  /* tail call? */
+        SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
+        lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
+      }
+      first = fs->nactvar;
+      nret = LUA_MULTRET;  /* return all values */
+    }
+    else {
+      if (nret == 1)  /* only one single value? */
+        first = luaK_exp2anyreg(fs, &e);
+      else {
+        luaK_exp2nextreg(fs, &e);  /* values must go to the `stack' */
+        first = fs->nactvar;  /* return all `active' values */
+        lua_assert(nret == fs->freereg - first);
+      }
+    }
+  }
+  luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
 }
 
 
 static void breakstat (LexState *ls) {
   /* stat -> BREAK [NAME] */
   FuncState *fs = ls->fs;
-  int currentlevel = fs->stacklevel;
-  Breaklabel *bl = fs->bl;
-  if (!bl)
-    luaK_error(ls, "no loop to break");
+  BlockCnt *bl = fs->bl;
+  int upval = 0;
   next(ls);  /* skip BREAK */
-  luaK_adjuststack(fs, currentlevel - bl->stacklevel);
+  while (bl && !bl->isbreakable) {
+    upval |= bl->upval;
+    bl = bl->previous;
+  }
+  if (!bl)
+    luaX_syntaxerror(ls, "no loop to break");
+  if (upval)
+    luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
   luaK_concat(fs, &bl->breaklist, luaK_jump(fs));
-  /* correct stack for compiler and symbolic execution */
-  luaK_adjuststack(fs, bl->stacklevel - currentlevel);
 }
 
 
-static int stat (LexState *ls) {
+static int statement (LexState *ls) {
   int line = ls->linenumber;  /* may be needed for error messages */
   switch (ls->t.token) {
     case TK_IF: {  /* stat -> ifstat */
@@ -1044,16 +1285,16 @@ static int stat (LexState *ls) {
       repeatstat(ls, line);
       return 0;
     }
-    case TK_FUNCTION: {  /* stat -> funcstat */
-      funcstat(ls, line);
+    case TK_FUNCTION: {
+      funcstat(ls, line);  /* stat -> funcstat */
       return 0;
     }
     case TK_LOCAL: {  /* stat -> localstat */
-      localstat(ls);
-      return 0;
-    }
-    case TK_NAME: case '%': {  /* stat -> namestat */
-      namestat(ls);
+      next(ls);  /* skip LOCAL */
+      if (testnext(ls, TK_FUNCTION))  /* local function? */
+        localfunc(ls);
+      else
+        localstat(ls);
       return 0;
     }
     case TK_RETURN: {  /* stat -> retstat */
@@ -1065,60 +1306,24 @@ static int stat (LexState *ls) {
       return 1;  /* must be last statement */
     }
     default: {
-      luaK_error(ls, "<statement> expected");
+      exprstat(ls);
       return 0;  /* to avoid warnings */
     }
   }
 }
 
 
-static void parlist (LexState *ls) {
-  /* parlist -> [ param { ',' param } ] */
-  int nparams = 0;
-  int dots = 0;
-  if (ls->t.token != ')') {  /* is `parlist' not empty? */
-    do {
-      switch (ls->t.token) {
-        case TK_DOTS: next(ls); dots = 1; break;
-        case TK_NAME: new_localvar(ls, str_checkname(ls), nparams++); break;
-        default: luaK_error(ls, "<name> or `...' expected");
-      }
-    } while (!dots && optional(ls, ','));
-  }
-  code_params(ls, nparams, dots);
-}
-
-
-static void body (LexState *ls, int needself, int line) {
-  /* body ->  '(' parlist ')' chunk END */
-  FuncState new_fs;
-  open_func(ls, &new_fs);
-  new_fs.f->lineDefined = line;
-  check(ls, '(');
-  if (needself) {
-    new_localvarstr(ls, "self", 0);
-    adjustlocalvars(ls, 1);
-  }
-  parlist(ls);
-  check(ls, ')');
-  chunk(ls);
-  check_match(ls, TK_END, TK_FUNCTION, line);
-  close_func(ls);
-  pushclosure(ls, &new_fs);
-}
-
-
-/* }====================================================================== */
-
-
 static void chunk (LexState *ls) {
-  /* chunk -> { stat [';'] } */
+  /* chunk -> { stat [`;'] } */
   int islast = 0;
+  enterlevel(ls);
   while (!islast && !block_follow(ls->t.token)) {
-    islast = stat(ls);
-    optional(ls, ';');
-    LUA_ASSERT(ls->fs->stacklevel == ls->fs->nactloc,
-               "stack size != # local vars");
+    islast = statement(ls);
+    testnext(ls, ';');
+    lua_assert(ls->fs->freereg >= ls->fs->nactvar);
+    ls->fs->freereg = ls->fs->nactvar;  /* free registers */
   }
+  leavelevel(ls);
 }
 
+/* }====================================================================== */
diff --git a/src/lparser.h b/src/lparser.h
index 445acea6..d6aaaf0e 100644
--- a/src/lparser.h
+++ b/src/lparser.h
@@ -1,13 +1,15 @@
 /*
-** $Id: lparser.h,v 1.26 2000/10/09 13:47:46 roberto Exp $
-** LL(1) Parser and code generator for Lua
+** $Id: lparser.h,v 1.47 2003/02/11 10:46:24 roberto Exp $
+** Lua Parser
 ** See Copyright Notice in lua.h
 */
 
 #ifndef lparser_h
 #define lparser_h
 
+#include "llimits.h"
 #include "lobject.h"
+#include "ltable.h"
 #include "lzio.h"
 
 
@@ -16,45 +18,54 @@
 */
 
 typedef enum {
-  VGLOBAL,
-  VLOCAL,
-  VINDEXED,
-  VEXP
+  VVOID,	/* no value */
+  VNIL,
+  VTRUE,
+  VFALSE,
+  VK,		/* info = index of constant in `k' */
+  VLOCAL,	/* info = local register */
+  VUPVAL,       /* info = index of upvalue in `upvalues' */
+  VGLOBAL,	/* info = index of table; aux = index of global name in `k' */
+  VINDEXED,	/* info = table register; aux = index register (or `k') */
+  VJMP,		/* info = instruction pc */
+  VRELOCABLE,	/* info = instruction pc */
+  VNONRELOC,	/* info = result register */
+  VCALL		/* info = result register */
 } expkind;
 
 typedef struct expdesc {
   expkind k;
-  union {
-    int index;  /* VGLOBAL: `kstr' index of global name; VLOCAL: stack index */
-    struct {
-      int t;  /* patch list of `exit when true' */
-      int f;  /* patch list of `exit when false' */
-    } l;
-  } u;
+  int info, aux;
+  int t;  /* patch list of `exit when true' */
+  int f;  /* patch list of `exit when false' */
 } expdesc;
 
 
+struct BlockCnt;  /* defined in lparser.c */
+
 
 /* state needed to generate code for a given function */
 typedef struct FuncState {
   Proto *f;  /* current function header */
+  Table *h;  /* table to find (and reuse) elements in `k' */
   struct FuncState *prev;  /* enclosing function */
   struct LexState *ls;  /* lexical state */
   struct lua_State *L;  /* copy of the Lua state */
-  int pc;  /* next position to code */
+  struct BlockCnt *bl;  /* chain of current blocks */
+  int pc;  /* next position to code (equivalent to `ncode') */
   int lasttarget;   /* `pc' of last `jump target' */
-  int jlt;  /* list of jumps to `lasttarget' */
-  short stacklevel;  /* number of values on activation register */
-  short nactloc;  /* number of active local variables */
-  short nupvalues;  /* number of upvalues */
-  int lastline;  /* line where last `lineinfo' was generated */
-  struct Breaklabel *bl;  /* chain of breakable blocks */
+  int jpc;  /* list of pending jumps to `pc' */
+  int freereg;  /* first free register */
+  int nk;  /* number of elements in `k' */
+  int np;  /* number of elements in `p' */
+  int nlocvars;  /* number of elements in `locvars' */
+  int nactvar;  /* number of active local variables */
   expdesc upvalues[MAXUPVALUES];  /* upvalues */
-  int actloc[MAXLOCALS];  /* local-variable stack (indices to locvars) */
+  int actvar[MAXVARS];  /* declared-variable stack */
 } FuncState;
 
 
-Proto *luaY_parser (lua_State *L, ZIO *z);
+Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff);
 
 
 #endif
diff --git a/src/lstate.c b/src/lstate.c
index 586c1085..b593658d 100644
--- a/src/lstate.c
+++ b/src/lstate.c
@@ -1,15 +1,19 @@
 /*
-** $Id: lstate.c,v 1.48 2000/10/30 16:29:59 roberto Exp $
+** $Id: lstate.c,v 1.123 2003/04/03 13:35:34 roberto Exp $
 ** Global State
 ** See Copyright Notice in lua.h
 */
 
 
-#include <stdio.h>
+#include <stdlib.h>
+
+#define lstate_c
 
 #include "lua.h"
 
+#include "ldebug.h"
 #include "ldo.h"
+#include "lfunc.h"
 #include "lgc.h"
 #include "llex.h"
 #include "lmem.h"
@@ -19,103 +23,198 @@
 #include "ltm.h"
 
 
-#ifdef LUA_DEBUG
-static lua_State *lua_state = NULL;
-void luaB_opentests (lua_State *L);
+/*
+** macro to allow the inclusion of user information in Lua state
+*/
+#ifndef LUA_USERSTATE
+#define EXTRASPACE	0
+#else
+union UEXTRASPACE {L_Umaxalign a; LUA_USERSTATE b;};
+#define EXTRASPACE (sizeof(union UEXTRASPACE))
 #endif
 
 
+
 /*
-** built-in implementation for ERRORMESSAGE. In a "correct" environment
-** ERRORMESSAGE should have an external definition, and so this function
-** would not be used.
+** you can change this function through the official API:
+** call `lua_setpanicf'
 */
-static int errormessage (lua_State *L) {
-  const char *s = lua_tostring(L, 1);
-  if (s == NULL) s = "(no message)";
-  fprintf(stderr, "error: %s\n", s);
+static int default_panic (lua_State *L) {
+  UNUSED(L);
   return 0;
 }
 
 
+static lua_State *mallocstate (lua_State *L) {
+  lu_byte *block = (lu_byte *)luaM_malloc(L, sizeof(lua_State) + EXTRASPACE);
+  if (block == NULL) return NULL;
+  else {
+    block += EXTRASPACE;
+    return cast(lua_State *, block);
+  }
+}
+
+
+static void freestate (lua_State *L, lua_State *L1) {
+  luaM_free(L, cast(lu_byte *, L1) - EXTRASPACE,
+               sizeof(lua_State) + EXTRASPACE);
+}
+
+
+static void stack_init (lua_State *L1, lua_State *L) {
+  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TObject);
+  L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
+  L1->top = L1->stack;
+  L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;
+  L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);
+  L1->ci = L1->base_ci;
+  L1->ci->state = CI_C;  /*  not a Lua function */
+  setnilvalue(L1->top++);  /* `function' entry for this `ci' */
+  L1->base = L1->ci->base = L1->top;
+  L1->ci->top = L1->top + LUA_MINSTACK;
+  L1->size_ci = BASIC_CI_SIZE;
+  L1->end_ci = L1->base_ci + L1->size_ci;
+}
+
+
+static void freestack (lua_State *L, lua_State *L1) {
+  luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);
+  luaM_freearray(L, L1->stack, L1->stacksize, TObject);
+}
+
+
 /*
 ** open parts that may cause memory-allocation errors
 */
 static void f_luaopen (lua_State *L, void *ud) {
-  int stacksize = *(int *)ud;
-  if (stacksize == 0)
-    stacksize = DEFAULT_STACK_SIZE;
-  else
-    stacksize += LUA_MINSTACK;
-  L->gt = luaH_new(L, 10);  /* table of globals */
-  luaD_init(L, stacksize);
-  luaS_init(L);
-  luaX_init(L);
+  /* create a new global state */
+  global_State *g = luaM_new(NULL, global_State);
+  UNUSED(ud);
+  if (g == NULL) luaD_throw(L, LUA_ERRMEM);
+  L->l_G = g;
+  g->mainthread = L;
+  g->GCthreshold = 0;  /* mark it as unfinished state */
+  g->strt.size = 0;
+  g->strt.nuse = 0;
+  g->strt.hash = NULL;
+  setnilvalue(defaultmeta(L));
+  setnilvalue(registry(L));
+  luaZ_initbuffer(L, &g->buff);
+  g->panic = default_panic;
+  g->rootgc = NULL;
+  g->rootudata = NULL;
+  g->tmudata = NULL;
+  setnilvalue(gkey(g->dummynode));
+  setnilvalue(gval(g->dummynode));
+  g->dummynode->next = NULL;
+  g->nblocks = sizeof(lua_State) + sizeof(global_State);
+  stack_init(L, L);  /* init stack */
+  /* create default meta table with a dummy table, and then close the loop */
+  defaultmeta(L)->tt = LUA_TTABLE;
+  sethvalue(defaultmeta(L), luaH_new(L, 0, 0));
+  hvalue(defaultmeta(L))->metatable = hvalue(defaultmeta(L));
+  sethvalue(gt(L), luaH_new(L, 0, 4));  /* table of globals */
+  sethvalue(registry(L), luaH_new(L, 4, 4));  /* registry */
+  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
   luaT_init(L);
-  lua_newtable(L);
-  lua_ref(L, 1);  /* create registry */
-  lua_register(L, LUA_ERRORMESSAGE, errormessage);
-#ifdef LUA_DEBUG
-  luaB_opentests(L);
-  if (lua_state == NULL) lua_state = L;  /* keep first state to be opened */
-#endif
-  LUA_ASSERT(lua_gettop(L) == 0, "wrong API stack");
+  luaX_init(L);
+  luaS_fix(luaS_newliteral(L, MEMERRMSG));
+  g->GCthreshold = 4*G(L)->nblocks;
 }
 
 
-LUA_API lua_State *lua_open (int stacksize) {
-  lua_State *L = luaM_new(NULL, lua_State);
-  if (L == NULL) return NULL;  /* memory allocation error */
+static void preinit_state (lua_State *L) {
   L->stack = NULL;
-  L->strt.size = L->udt.size = 0;
-  L->strt.nuse = L->udt.nuse = 0;
-  L->strt.hash = NULL;
-  L->udt.hash = NULL;
-  L->Mbuffer = NULL;
-  L->Mbuffsize = 0;
-  L->rootproto = NULL;
-  L->rootcl = NULL;
-  L->roottable = NULL;
-  L->TMtable = NULL;
-  L->last_tag = -1;
-  L->refArray = NULL;
-  L->refSize = 0;
-  L->refFree = NONEXT;
-  L->nblocks = sizeof(lua_State);
-  L->GCthreshold = MAX_INT;  /* to avoid GC during pre-definitions */
-  L->callhook = NULL;
-  L->linehook = NULL;
-  L->allowhooks = 1;
+  L->stacksize = 0;
   L->errorJmp = NULL;
-  if (luaD_runprotected(L, f_luaopen, &stacksize) != 0) {
-    /* memory allocation error: free partial state */
-    lua_close(L);
-    return NULL;
+  L->hook = NULL;
+  L->hookmask = L->hookinit = 0;
+  L->basehookcount = 0;
+  L->allowhook = 1;
+  resethookcount(L);
+  L->openupval = NULL;
+  L->size_ci = 0;
+  L->nCcalls = 0;
+  L->base_ci = L->ci = NULL;
+  L->errfunc = 0;
+  setnilvalue(gt(L));
+}
+
+
+static void close_state (lua_State *L) {
+  luaF_close(L, L->stack);  /* close all upvalues for this thread */
+  if (G(L)) {  /* close global state */
+    luaC_sweep(L, 1);  /* collect all elements */
+    lua_assert(G(L)->rootgc == NULL);
+    lua_assert(G(L)->rootudata == NULL);
+    luaS_freeall(L);
+    luaZ_freebuffer(L, &G(L)->buff);
+  }
+  freestack(L, L);
+  if (G(L)) {
+    lua_assert(G(L)->nblocks == sizeof(lua_State) + sizeof(global_State));
+    luaM_freelem(NULL, G(L));
+  }
+  freestate(NULL, L);
+}
+
+
+lua_State *luaE_newthread (lua_State *L) {
+  lua_State *L1 = mallocstate(L);
+  luaC_link(L, valtogco(L1), LUA_TTHREAD);
+  preinit_state(L1);
+  L1->l_G = L->l_G;
+  stack_init(L1, L);  /* init stack */
+  setobj2n(gt(L1), gt(L));  /* share table of globals */
+  return L1;
+}
+
+
+void luaE_freethread (lua_State *L, lua_State *L1) {
+  luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
+  lua_assert(L1->openupval == NULL);
+  freestack(L, L1);
+  freestate(L, L1);
+}
+
+
+LUA_API lua_State *lua_open (void) {
+  lua_State *L = mallocstate(NULL);
+  if (L) {  /* allocation OK? */
+    L->tt = LUA_TTHREAD;
+    L->marked = 0;
+    L->next = L->gclist = NULL;
+    preinit_state(L);
+    L->l_G = NULL;
+    if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {
+      /* memory allocation error: free partial state */
+      close_state(L);
+      L = NULL;
+    }
   }
-  L->GCthreshold = 2*L->nblocks;
+  lua_userstateopen(L);
   return L;
 }
 
 
+static void callallgcTM (lua_State *L, void *ud) {
+  UNUSED(ud);
+  luaC_callGCTM(L);  /* call GC metamethods for all udata */
+}
+
+
 LUA_API void lua_close (lua_State *L) {
-  LUA_ASSERT(L != lua_state || lua_gettop(L) == 0, "garbage in C stack");
-  luaC_collect(L, 1);  /* collect all elements */
-  LUA_ASSERT(L->rootproto == NULL, "list should be empty");
-  LUA_ASSERT(L->rootcl == NULL, "list should be empty");
-  LUA_ASSERT(L->roottable == NULL, "list should be empty");
-  luaS_freeall(L);
-  if (L->stack)
-    L->nblocks -= (L->stack_last - L->stack + 1)*sizeof(TObject);
-  luaM_free(L, L->stack);
-  L->nblocks -= (L->last_tag+1)*sizeof(struct TM);
-  luaM_free(L, L->TMtable);
-  L->nblocks -= (L->refSize)*sizeof(struct Ref);
-  luaM_free(L, L->refArray);
-  L->nblocks -= (L->Mbuffsize)*sizeof(char);
-  luaM_free(L, L->Mbuffer);
-  LUA_ASSERT(L->nblocks == sizeof(lua_State), "wrong count for nblocks");
-  luaM_free(L, L);
-  LUA_ASSERT(L != lua_state || memdebug_numblocks == 0, "memory leak!");
-  LUA_ASSERT(L != lua_state || memdebug_total == 0,"memory leak!");
+  lua_lock(L);
+  L = G(L)->mainthread;  /* only the main thread can be closed */
+  luaF_close(L, L->stack);  /* close all upvalues for this thread */
+  luaC_separateudata(L);  /* separate udata that have GC metamethods */
+  L->errfunc = 0;  /* no error function during GC metamethods */
+  do {  /* repeat until no more errors */
+    L->ci = L->base_ci;
+    L->base = L->top = L->ci->base;
+    L->nCcalls = 0;
+  } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
+  lua_assert(G(L)->tmudata == NULL);
+  close_state(L);
 }
 
diff --git a/src/lstate.h b/src/lstate.h
index 0c8f5521..5422f1b1 100644
--- a/src/lstate.h
+++ b/src/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 1.41 2000/10/05 13:00:17 roberto Exp $
+** $Id: lstate.h,v 1.109 2003/02/27 11:52:30 roberto Exp $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -7,71 +7,189 @@
 #ifndef lstate_h
 #define lstate_h
 
-#include "lobject.h"
 #include "lua.h"
-#include "luadebug.h"
-
 
-
-typedef TObject *StkId;  /* index to stack elements */
+#include "lobject.h"
+#include "ltm.h"
+#include "lzio.h"
 
 
 /*
-** marks for Reference array
+** macros for thread synchronization inside Lua core machine:
+** all accesses to the global state and to global objects are synchronized.
+** Because threads can read the stack of other threads
+** (when running garbage collection),
+** a thread must also synchronize any write-access to its own stack.
+** Unsynchronized accesses are allowed only when reading its own stack,
+** or when reading immutable fields from global objects
+** (such as string values and udata values). 
 */
-#define NONEXT          -1      /* to end the free list */
-#define HOLD            -2
-#define COLLECTED       -3
-#define LOCK            -4
+#ifndef lua_lock
+#define lua_lock(L)	((void) 0)
+#endif
 
+#ifndef lua_unlock
+#define lua_unlock(L)	((void) 0)
+#endif
+
+
+#ifndef lua_userstateopen
+#define lua_userstateopen(l)
+#endif
 
-struct Ref {
-  TObject o;
-  int st;  /* can be LOCK, HOLD, COLLECTED, or next (for free list) */
-};
 
 
 struct lua_longjmp;  /* defined in ldo.c */
-struct TM;  /* defined in ltm.h */
+
+
+/* default meta table (both for tables and udata) */
+#define defaultmeta(L)	(&G(L)->_defaultmeta)
+
+/* table of globals */
+#define gt(L)	(&L->_gt)
+
+/* registry */
+#define registry(L)	(&G(L)->_registry)
+
+
+/* extra stack space to handle TM calls and some other extras */
+#define EXTRA_STACK   5
+
+
+#define BASIC_CI_SIZE           8
+
+#define BASIC_STACK_SIZE        (2*LUA_MINSTACK)
+
 
 
 typedef struct stringtable {
+  GCObject **hash;
+  ls_nstr nuse;  /* number of elements */
   int size;
-  lint32 nuse;  /* number of elements */
-  TString **hash;
 } stringtable;
 
 
+/*
+** informations about a call
+*/
+typedef struct CallInfo {
+  StkId base;  /* base for called function */
+  StkId	top;  /* top for this function */
+  int state;  /* bit fields; see below */
+  union {
+    struct {  /* for Lua functions */
+      const Instruction *savedpc;
+      const Instruction **pc;  /* points to `pc' variable in `luaV_execute' */
+      int tailcalls;  /* number of tail calls lost under this entry */
+    } l;
+    struct {  /* for C functions */
+      int dummy;  /* just to avoid an empty struct */
+    } c;
+  } u;
+} CallInfo;
+
+
+/*
+** bit fields for `CallInfo.state'
+*/
+#define CI_C		(1<<0)  /* 1 if function is a C function */
+/* 1 if (Lua) function has an active `luaV_execute' running it */
+#define CI_HASFRAME	(1<<1)
+/* 1 if Lua function is calling another Lua function (and therefore its
+   `pc' is being used by the other, and therefore CI_SAVEDPC is 1 too) */
+#define CI_CALLING	(1<<2)
+#define CI_SAVEDPC	(1<<3)  /* 1 if `savedpc' is updated */
+#define CI_YIELD	(1<<4)  /* 1 if thread is suspended */
+
+
+#define ci_func(ci)	(clvalue((ci)->base - 1))
+
 
+/*
+** `global state', shared by all threads of this state
+*/
+typedef struct global_State {
+  stringtable strt;  /* hash table for strings */
+  GCObject *rootgc;  /* list of (almost) all collectable objects */
+  GCObject *rootudata;   /* (separated) list of all userdata */
+  GCObject *tmudata;  /* list of userdata to be GC */
+  Mbuffer buff;  /* temporary buffer for string concatentation */
+  lu_mem GCthreshold;
+  lu_mem nblocks;  /* number of `bytes' currently allocated */
+  lua_CFunction panic;  /* to be called in unprotected errors */
+  TObject _registry;
+  TObject _defaultmeta;
+  struct lua_State *mainthread;
+  Node dummynode[1];  /* common node array for all empty tables */
+  TString *tmname[TM_N];  /* array with tag-method names */
+} global_State;
+
+
+/*
+** `per thread' state
+*/
 struct lua_State {
-  /* thread-specific state */
+  CommonHeader;
   StkId top;  /* first free slot in the stack */
-  StkId stack;  /* stack base */
+  StkId base;  /* base of current function */
+  global_State *l_G;
+  CallInfo *ci;  /* call info for current function */
   StkId stack_last;  /* last free slot in the stack */
+  StkId stack;  /* stack base */
   int stacksize;
-  StkId Cbase;  /* base for current C function */
+  CallInfo *end_ci;  /* points after end of ci array*/
+  CallInfo *base_ci;  /* array of CallInfo's */
+  unsigned short size_ci;  /* size of array `base_ci' */
+  unsigned short nCcalls;  /* number of nested C calls */
+  lu_byte hookmask;
+  lu_byte allowhook;
+  lu_byte hookinit;
+  int basehookcount;
+  int hookcount;
+  lua_Hook hook;
+  TObject _gt;  /* table of globals */
+  GCObject *openupval;  /* list of open upvalues in this stack */
+  GCObject *gclist;
   struct lua_longjmp *errorJmp;  /* current error recover point */
-  char *Mbuffer;  /* global buffer */
-  size_t Mbuffsize;  /* size of Mbuffer */
-  /* global state */
-  Proto *rootproto;  /* list of all prototypes */
-  Closure *rootcl;  /* list of all closures */
-  Hash *roottable;  /* list of all tables */
-  stringtable strt;  /* hash table for strings */
-  stringtable udt;   /* hash table for udata */
-  Hash *gt;  /* table for globals */
-  struct TM *TMtable;  /* table for tag methods */
-  int last_tag;  /* last used tag in TMtable */
-  struct Ref *refArray;  /* locked objects */
-  int refSize;  /* size of refArray */
-  int refFree;  /* list of free positions in refArray */
-  unsigned long GCthreshold;
-  unsigned long nblocks;  /* number of `bytes' currently allocated */
-  lua_Hook callhook;
-  lua_Hook linehook;
-  int allowhooks;
+  ptrdiff_t errfunc;  /* current error handling function (stack index) */
+};
+
+
+#define G(L)	(L->l_G)
+
+
+/*
+** Union of all collectable objects
+*/
+union GCObject {
+  GCheader gch;
+  union TString ts;
+  union Udata u;
+  union Closure cl;
+  struct Table h;
+  struct Proto p;
+  struct UpVal uv;
+  struct lua_State th;  /* thread */
 };
 
 
+/* macros to convert a GCObject into a specific value */
+#define gcotots(o)	check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))
+#define gcotou(o)	check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))
+#define gcotocl(o)	check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))
+#define gcotoh(o)	check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h))
+#define gcotop(o)	check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p))
+#define gcotouv(o)	check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))
+#define ngcotouv(o) \
+	check_exp((o) == NULL || (o)->gch.tt == LUA_TUPVAL, &((o)->uv))
+#define gcototh(o)	check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))
+
+/* macro to convert any value into a GCObject */
+#define valtogco(v)	(cast(GCObject *, (v)))
+
+
+lua_State *luaE_newthread (lua_State *L);
+void luaE_freethread (lua_State *L, lua_State *L1);
+
 #endif
 
diff --git a/src/lstring.c b/src/lstring.c
index a415a7d3..8cbddbd2 100644
--- a/src/lstring.c
+++ b/src/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 1.45a 2000/10/30 17:49:19 roberto Exp $
+** $Id: lstring.c,v 1.78 2002/12/04 17:38:31 roberto Exp $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -7,6 +7,8 @@
 
 #include <string.h>
 
+#define lstring_c
+
 #include "lua.h"
 
 #include "lmem.h"
@@ -15,141 +17,86 @@
 #include "lstring.h"
 
 
-/*
-** type equivalent to TString, but with maximum alignment requirements
-*/
-union L_UTString {
-  TString ts;
-  union L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
-};
-
-
-
-void luaS_init (lua_State *L) {
-  L->strt.hash = luaM_newvector(L, 1, TString *);
-  L->udt.hash = luaM_newvector(L, 1, TString *);
-  L->nblocks += 2*sizeof(TString *);
-  L->strt.size = L->udt.size = 1;
-  L->strt.nuse = L->udt.nuse = 0;
-  L->strt.hash[0] = L->udt.hash[0] = NULL;
-}
-
 
 void luaS_freeall (lua_State *L) {
-  LUA_ASSERT(L->strt.nuse==0, "non-empty string table");
-  L->nblocks -= (L->strt.size + L->udt.size)*sizeof(TString *);
-  luaM_free(L, L->strt.hash);
-  LUA_ASSERT(L->udt.nuse==0, "non-empty udata table");
-  luaM_free(L, L->udt.hash);
-}
-
-
-static unsigned long hash_s (const char *s, size_t l) {
-  unsigned long h = l;  /* seed */
-  size_t step = (l>>5)|1;  /* if string is too long, don't hash all its chars */
-  for (; l>=step; l-=step)
-    h = h ^ ((h<<5)+(h>>2)+(unsigned char)*(s++));
-  return h;
+  lua_assert(G(L)->strt.nuse==0);
+  luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);
 }
 
 
-void luaS_resize (lua_State *L, stringtable *tb, int newsize) {
-  TString **newhash = luaM_newvector(L, newsize, TString *);
+void luaS_resize (lua_State *L, int newsize) {
+  GCObject **newhash = luaM_newvector(L, newsize, GCObject *);
+  stringtable *tb = &G(L)->strt;
   int i;
   for (i=0; i<newsize; i++) newhash[i] = NULL;
   /* rehash */
   for (i=0; i<tb->size; i++) {
-    TString *p = tb->hash[i];
+    GCObject *p = tb->hash[i];
     while (p) {  /* for each node in the list */
-      TString *next = p->nexthash;  /* save next */
-      unsigned long h = (tb == &L->strt) ? p->u.s.hash : IntPoint(p->u.d.value);
-      int h1 = h&(newsize-1);  /* new position */
-      LUA_ASSERT(h%newsize == (h&(newsize-1)),
-                    "a&(x-1) == a%x, for x power of 2");
-      p->nexthash = newhash[h1];  /* chain it in new position */
+      GCObject *next = p->gch.next;  /* save next */
+      lu_hash h = gcotots(p)->tsv.hash;
+      int h1 = lmod(h, newsize);  /* new position */
+      lua_assert(cast(int, h%newsize) == lmod(h, newsize));
+      p->gch.next = newhash[h1];  /* chain it */
       newhash[h1] = p;
       p = next;
     }
   }
-  luaM_free(L, tb->hash);
-  L->nblocks += (newsize - tb->size)*sizeof(TString *);
+  luaM_freearray(L, tb->hash, tb->size, TString *);
   tb->size = newsize;
   tb->hash = newhash;
 }
 
 
-static void newentry (lua_State *L, stringtable *tb, TString *ts, int h) {
-  ts->nexthash = tb->hash[h];  /* chain new entry */
-  tb->hash[h] = ts;
+static TString *newlstr (lua_State *L, const char *str, size_t l, lu_hash h) {
+  TString *ts = cast(TString *, luaM_malloc(L, sizestring(l)));
+  stringtable *tb;
+  ts->tsv.len = l;
+  ts->tsv.hash = h;
+  ts->tsv.marked = 0;
+  ts->tsv.tt = LUA_TSTRING;
+  ts->tsv.reserved = 0;
+  memcpy(ts+1, str, l*sizeof(char));
+  ((char *)(ts+1))[l] = '\0';  /* ending 0 */
+  tb = &G(L)->strt;
+  h = lmod(h, tb->size);
+  ts->tsv.next = tb->hash[h];  /* chain new entry */
+  tb->hash[h] = valtogco(ts);
   tb->nuse++;
-  if (tb->nuse > (lint32)tb->size && tb->size < MAX_INT/2)  /* too crowded? */
-    luaS_resize(L, tb, tb->size*2);
-}
-
-
-
-TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
-  unsigned long h = hash_s(str, l);
-  int h1 = h & (L->strt.size-1);
-  TString *ts;
-  for (ts = L->strt.hash[h1]; ts; ts = ts->nexthash) {
-    if (ts->len == l && (memcmp(str, ts->str, l) == 0))
-      return ts;
-  }
-  /* not found */
-  ts = (TString *)luaM_malloc(L, sizestring(l));
-  ts->marked = 0;
-  ts->nexthash = NULL;
-  ts->len = l;
-  ts->u.s.hash = h;
-  ts->u.s.constindex = 0;
-  memcpy(ts->str, str, l);
-  ts->str[l] = 0;  /* ending 0 */
-  L->nblocks += sizestring(l);
-  newentry(L, &L->strt, ts, h1);  /* insert it on table */
-  return ts;
-}
-
-
-TString *luaS_newudata (lua_State *L, size_t s, void *udata) {
-  union L_UTString *uts = (union L_UTString *)luaM_malloc(L,
-                                (lint32)sizeof(union L_UTString)+s);
-  TString *ts = &uts->ts;
-  ts->marked = 0;
-  ts->nexthash = NULL;
-  ts->len = s;
-  ts->u.d.tag = 0;
-  ts->u.d.value = (s > 0) ? uts+1 : udata;
-  L->nblocks += sizestring(s);
- /* insert it on table */
-  newentry(L, &L->udt, ts, IntPoint(ts->u.d.value) & (L->udt.size-1));
+  if (tb->nuse > cast(ls_nstr, tb->size) && tb->size <= MAX_INT/2)
+    luaS_resize(L, tb->size*2);  /* too crowded */
   return ts;
 }
 
 
-TString *luaS_createudata (lua_State *L, void *udata, int tag) {
-  int h1 = IntPoint(udata) & (L->udt.size-1);
-  TString *ts;
-  for (ts = L->udt.hash[h1]; ts; ts = ts->nexthash) {
-    if (udata == ts->u.d.value && (tag == ts->u.d.tag || tag == LUA_ANYTAG))
+TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
+  GCObject *o;
+  lu_hash h = (lu_hash)l;  /* seed */
+  size_t step = (l>>5)+1;  /* if string is too long, don't hash all its chars */
+  size_t l1;
+  for (l1=l; l1>=step; l1-=step)  /* compute hash */
+    h = h ^ ((h<<5)+(h>>2)+(unsigned char)(str[l1-1]));
+  for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)];
+       o != NULL;
+       o = o->gch.next) {
+    TString *ts = gcotots(o);
+    if (ts->tsv.len == l && (memcmp(str, getstr(ts), l) == 0))
       return ts;
   }
-  /* not found */
-  ts = luaS_newudata(L, 0, udata);
-  if (tag != LUA_ANYTAG)
-    ts->u.d.tag = tag;
-  return ts;
+  return newlstr(L, str, l, h);  /* not found */
 }
 
 
-TString *luaS_new (lua_State *L, const char *str) {
-  return luaS_newlstr(L, str, strlen(str));
-}
-
-
-TString *luaS_newfixed (lua_State *L, const char *str) {
-  TString *ts = luaS_new(L, str);
-  if (ts->marked == 0) ts->marked = FIXMARK;  /* avoid GC */
-  return ts;
+Udata *luaS_newudata (lua_State *L, size_t s) {
+  Udata *u;
+  u = cast(Udata *, luaM_malloc(L, sizeudata(s)));
+  u->uv.marked = (1<<1);  /* is not finalized */
+  u->uv.tt = LUA_TUSERDATA;
+  u->uv.len = s;
+  u->uv.metatable = hvalue(defaultmeta(L));
+  /* chain it on udata list */
+  u->uv.next = G(L)->rootudata;
+  G(L)->rootudata = valtogco(u);
+  return u;
 }
 
diff --git a/src/lstring.h b/src/lstring.h
index 67ede68d..be5a1e37 100644
--- a/src/lstring.h
+++ b/src/lstring.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.h,v 1.24 2000/10/30 17:49:19 roberto Exp $
+** $Id: lstring.h,v 1.37 2002/08/16 14:45:55 roberto Exp $
 ** String table (keep all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -12,26 +12,22 @@
 #include "lstate.h"
 
 
-/*
-** any TString with mark>=FIXMARK is never collected.
-** Marks>=RESERVEDMARK are used to identify reserved words.
-*/
-#define FIXMARK		2
-#define RESERVEDMARK	3
 
+#define sizestring(l)	(cast(lu_mem, sizeof(union TString))+ \
+                         (cast(lu_mem, l)+1)*sizeof(char))
+
+#define sizeudata(l)	(cast(lu_mem, sizeof(union Udata))+(l))
 
-#define sizestring(l)	((long)sizeof(TString) + \
-                         ((long)(l+1)-TSPACK)*(long)sizeof(char))
+#define luaS_new(L, s)	(luaS_newlstr(L, s, strlen(s)))
+#define luaS_newliteral(L, s)	(luaS_newlstr(L, "" s, \
+                                 (sizeof(s)/sizeof(char))-1))
 
+#define luaS_fix(s)	((s)->tsv.marked |= (1<<4))
 
-void luaS_init (lua_State *L);
-void luaS_resize (lua_State *L, stringtable *tb, int newsize);
-TString *luaS_newudata (lua_State *L, size_t s, void *udata);
-TString *luaS_createudata (lua_State *L, void *udata, int tag);
+void luaS_resize (lua_State *L, int newsize);
+Udata *luaS_newudata (lua_State *L, size_t s);
 void luaS_freeall (lua_State *L);
 TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
-TString *luaS_new (lua_State *L, const char *str);
-TString *luaS_newfixed (lua_State *L, const char *str);
 
 
 #endif
diff --git a/src/ltable.c b/src/ltable.c
index b28712d9..0c64adb1 100644
--- a/src/ltable.c
+++ b/src/ltable.c
@@ -1,13 +1,17 @@
 /*
-** $Id: ltable.c,v 1.58 2000/10/26 12:47:05 roberto Exp $
+** $Id: ltable.c,v 1.132 2003/04/03 13:35:34 roberto Exp $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
 
 
 /*
-** Implementation of tables (aka arrays, objects, or hash tables);
-** uses a mix of chained scatter table with Brent's variation.
+** Implementation of tables (aka arrays, objects, or hash tables).
+** Tables keep its elements in two parts: an array part and a hash part.
+** Non-negative integer keys are all candidates to be kept in the array
+** part. The actual size of the array is the largest `n' such that at
+** least half the slots between 0 and n are in use.
+** Hash uses a mix of chained scatter table with Brent's variation.
 ** A main invariant of these tables is that, if an element is not
 ** in its main position (i.e. the `original' position that its hash gives
 ** to it), then the colliding element is in its own main position.
@@ -17,21 +21,74 @@
 ** performance penalties.
 */
 
+#include <string.h>
+
+#define ltable_c
 
 #include "lua.h"
 
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
 #include "lmem.h"
 #include "lobject.h"
 #include "lstate.h"
-#include "lstring.h"
 #include "ltable.h"
 
 
-#define gcsize(L, n)	(sizeof(Hash)+(n)*sizeof(Node))
+/*
+** max size of array part is 2^MAXBITS
+*/
+#if BITS_INT > 26
+#define MAXBITS		24
+#else
+#define MAXBITS		(BITS_INT-2)
+#endif
+
+/* check whether `x' < 2^MAXBITS */
+#define toobig(x)	((((x)-1) >> MAXBITS) != 0)
 
 
+/* function to convert a lua_Number to int (with any rounding method) */
+#ifndef lua_number2int
+#define lua_number2int(i,n)	((i)=(int)(n))
+#endif
 
-#define TagDefault LUA_TTABLE
+
+#define hashpow2(t,n)      (gnode(t, lmod((n), sizenode(t))))
+  
+#define hashstr(t,str)  hashpow2(t, (str)->tsv.hash)
+#define hashboolean(t,p)        hashpow2(t, p)
+
+
+/*
+** for some types, it is better to avoid modulus by power of 2, as
+** they tend to have many 2 factors.
+*/
+#define hashmod(t,n)	(gnode(t, ((n) % ((sizenode(t)-1)|1))))
+
+
+#define hashpointer(t,p)	hashmod(t, IntPoint(p))
+
+
+/*
+** number of ints inside a lua_Number
+*/
+#define numints		cast(int, sizeof(lua_Number)/sizeof(int))
+
+
+/*
+** hash for lua_Numbers
+*/
+static Node *hashnum (const Table *t, lua_Number n) {
+  unsigned int a[numints];
+  int i;
+  n += 1;  /* normalize number (avoid -0) */
+  lua_assert(sizeof(a) <= sizeof(n));
+  memcpy(a, &n, sizeof(a));
+  for (i = 1; i < numints; i++) a[0] += a[i];
+  return hashmod(t, cast(lu_hash, a[0]));
+}
 
 
 
@@ -39,226 +96,299 @@
 ** returns the `main' position of an element in a table (that is, the index
 ** of its hash value)
 */
-Node *luaH_mainposition (const Hash *t, const TObject *key) {
-  unsigned long h;
+Node *luaH_mainposition (const Table *t, const TObject *key) {
   switch (ttype(key)) {
     case LUA_TNUMBER:
-      h = (unsigned long)(long)nvalue(key);
-      break;
+      return hashnum(t, nvalue(key));
     case LUA_TSTRING:
-      h = tsvalue(key)->u.s.hash;
-      break;
-    case LUA_TUSERDATA:
-      h = IntPoint(tsvalue(key));
-      break;
-    case LUA_TTABLE:
-      h = IntPoint(hvalue(key));
-      break;
-    case LUA_TFUNCTION:
-      h = IntPoint(clvalue(key));
-      break;
+      return hashstr(t, tsvalue(key));
+    case LUA_TBOOLEAN:
+      return hashboolean(t, bvalue(key));
+    case LUA_TLIGHTUSERDATA:
+      return hashpointer(t, pvalue(key));
     default:
-      return NULL;  /* invalid key */
+      return hashpointer(t, gcvalue(key));
   }
-  LUA_ASSERT(h%(unsigned int)t->size == (h&((unsigned int)t->size-1)),
-            "a&(x-1) == a%x, for x power of 2");
-  return &t->node[h&(t->size-1)];
 }
 
 
-static const TObject *luaH_getany (lua_State *L, const Hash *t,
-                                   const TObject *key) {
-  Node *n = luaH_mainposition(t, key);
-  if (!n)
-    lua_error(L, "table index is nil");
-  else do {
-    if (luaO_equalObj(key, &n->key))
-      return &n->val;
-    n = n->next;
-  } while (n);
-  return &luaO_nilobject;  /* key not found */
+/*
+** returns the index for `key' if `key' is an appropriate key to live in
+** the array part of the table, -1 otherwise.
+*/
+static int arrayindex (const TObject *key) {
+  if (ttisnumber(key)) {
+    int k;
+    lua_number2int(k, (nvalue(key)));
+    if (cast(lua_Number, k) == nvalue(key) && k >= 1 && !toobig(k))
+      return k;
+  }
+  return -1;  /* `key' did not match some condition */
 }
 
 
-/* specialized version for numbers */
-const TObject *luaH_getnum (const Hash *t, Number key) {
-  Node *n = &t->node[(unsigned long)(long)key&(t->size-1)];
-  do {
-    if (ttype(&n->key) == LUA_TNUMBER && nvalue(&n->key) == key)
-      return &n->val;
-    n = n->next;
-  } while (n);
-  return &luaO_nilobject;  /* key not found */
+/*
+** returns the index of a `key' for table traversals. First goes all
+** elements in the array part, then elements in the hash part. The
+** beginning and end of a traversal are signalled by -1.
+*/
+static int luaH_index (lua_State *L, Table *t, StkId key) {
+  int i;
+  if (ttisnil(key)) return -1;  /* first iteration */
+  i = arrayindex(key);
+  if (0 <= i && i <= t->sizearray) {  /* is `key' inside array part? */
+    return i-1;  /* yes; that's the index (corrected to C) */
+  }
+  else {
+    const TObject *v = luaH_get(t, key);
+    if (v == &luaO_nilobject)
+      luaG_runerror(L, "invalid key for `next'");
+    i = cast(int, (cast(const lu_byte *, v) -
+                   cast(const lu_byte *, gval(gnode(t, 0)))) / sizeof(Node));
+    return i + t->sizearray;  /* hash elements are numbered after array ones */
+  }
 }
 
 
-/* specialized version for strings */
-const TObject *luaH_getstr (const Hash *t, TString *key) {
-  Node *n = &t->node[key->u.s.hash&(t->size-1)];
-  do {
-    if (ttype(&n->key) == LUA_TSTRING && tsvalue(&n->key) == key)
-      return &n->val;
-    n = n->next;
-  } while (n);
-  return &luaO_nilobject;  /* key not found */
+int luaH_next (lua_State *L, Table *t, StkId key) {
+  int i = luaH_index(L, t, key);  /* find original element */
+  for (i++; i < t->sizearray; i++) {  /* try first array part */
+    if (!ttisnil(&t->array[i])) {  /* a non-nil value? */
+      setnvalue(key, cast(lua_Number, i+1));
+      setobj2s(key+1, &t->array[i]);
+      return 1;
+    }
+  }
+  for (i -= t->sizearray; i < sizenode(t); i++) {  /* then hash part */
+    if (!ttisnil(gval(gnode(t, i)))) {  /* a non-nil value? */
+      setobj2s(key, gkey(gnode(t, i)));
+      setobj2s(key+1, gval(gnode(t, i)));
+      return 1;
+    }
+  }
+  return 0;  /* no more elements */
 }
 
 
-const TObject *luaH_get (lua_State *L, const Hash *t, const TObject *key) {
-  switch (ttype(key)) {
-    case LUA_TNUMBER: return luaH_getnum(t, nvalue(key));
-    case LUA_TSTRING: return luaH_getstr(t, tsvalue(key));
-    default:         return luaH_getany(L, t, key);
+/*
+** {=============================================================
+** Rehash
+** ==============================================================
+*/
+
+
+static void computesizes  (int nums[], int ntotal, int *narray, int *nhash) {
+  int i;
+  int a = nums[0];  /* number of elements smaller than 2^i */
+  int na = a;  /* number of elements to go to array part */
+  int n = (na == 0) ? -1 : 0;  /* (log of) optimal size for array part */
+  for (i = 1; a < *narray && *narray >= twoto(i-1); i++) {
+    if (nums[i] > 0) {
+      a += nums[i];
+      if (a >= twoto(i-1)) {  /* more than half elements in use? */
+        n = i;
+        na = a;
+      }
+    }
   }
+  lua_assert(na <= *narray && *narray <= ntotal);
+  *nhash = ntotal - na;
+  *narray = (n == -1) ? 0 : twoto(n);
+  lua_assert(na <= *narray && na >= *narray/2);
 }
 
 
-Node *luaH_next (lua_State *L, const Hash *t, const TObject *key) {
-  int i;
-  if (ttype(key) == LUA_TNIL)
-    i = 0;  /* first iteration */
-  else {
-    const TObject *v = luaH_get(L, t, key);
-    if (v == &luaO_nilobject)
-      lua_error(L, "invalid key for `next'");
-    i = (int)(((const char *)v -
-               (const char *)(&t->node[0].val)) / sizeof(Node)) + 1;
+static void numuse (const Table *t, int *narray, int *nhash) {
+  int nums[MAXBITS+1];
+  int i, lg;
+  int totaluse = 0;
+  /* count elements in array part */
+  for (i=0, lg=0; lg<=MAXBITS; lg++) {  /* for each slice [2^(lg-1) to 2^lg) */
+    int ttlg = twoto(lg);  /* 2^lg */
+    if (ttlg > t->sizearray) {
+      ttlg = t->sizearray;
+      if (i >= ttlg) break;
+    }
+    nums[lg] = 0;
+    for (; i<ttlg; i++) {
+      if (!ttisnil(&t->array[i])) {
+        nums[lg]++;
+        totaluse++;
+      }
+    }
   }
-  for (; i<t->size; i++) {
-    Node *n = node(t, i);
-    if (ttype(val(n)) != LUA_TNIL)
-      return n;
+  for (; lg<=MAXBITS; lg++) nums[lg] = 0;  /* reset other counts */
+  *narray = totaluse;  /* all previous uses were in array part */
+  /* count elements in hash part */
+  i = sizenode(t);
+  while (i--) {
+    Node *n = &t->node[i];
+    if (!ttisnil(gval(n))) {
+      int k = arrayindex(gkey(n));
+      if (k >= 0) {  /* is `key' an appropriate array index? */
+        nums[luaO_log2(k-1)+1]++;  /* count as such */
+        (*narray)++;
+      }
+      totaluse++;
+    }
   }
-  return NULL;  /* no more elements */
+  computesizes(nums, totaluse, narray, nhash);
 }
 
 
-/*
-** try to remove a key without value from a table. To avoid problems with
-** hash, change `key' for a number with the same hash.
-*/
-void luaH_remove (Hash *t, TObject *key) {
-  if (ttype(key) == LUA_TNUMBER ||
-       (ttype(key) == LUA_TSTRING && tsvalue(key)->len <= 30))
-  return;  /* do not remove numbers nor small strings */
+static void setarrayvector (lua_State *L, Table *t, int size) {
+  int i;
+  luaM_reallocvector(L, t->array, t->sizearray, size, TObject);
+  for (i=t->sizearray; i<size; i++)
+     setnilvalue(&t->array[i]);
+  t->sizearray = size;
+}
+
+
+static void setnodevector (lua_State *L, Table *t, int lsize) {
+  int i;
+  int size = twoto(lsize);
+  if (lsize > MAXBITS)
+    luaG_runerror(L, "table overflow");
+  if (lsize == 0) {  /* no elements to hash part? */
+    t->node = G(L)->dummynode;  /* use common `dummynode' */
+    lua_assert(ttisnil(gkey(t->node)));  /* assert invariants: */
+    lua_assert(ttisnil(gval(t->node)));
+    lua_assert(t->node->next == NULL);  /* (`dummynode' must be empty) */
+  }
   else {
-    /* try to find a number `n' with the same hash as `key' */
-    Node *mp = luaH_mainposition(t, key);
-    int n = mp - &t->node[0];
-    /* make sure `n' is not in `t' */
-    while (luaH_getnum(t, n) != &luaO_nilobject) {
-      if (n >= MAX_INT - t->size)
-        return;  /* give up; (to avoid overflow) */
-      n += t->size;
+    t->node = luaM_newvector(L, size, Node);
+    for (i=0; i<size; i++) {
+      t->node[i].next = NULL;
+      setnilvalue(gkey(gnode(t, i)));
+      setnilvalue(gval(gnode(t, i)));
     }
-    ttype(key) = LUA_TNUMBER;
-    nvalue(key) = n;
-    LUA_ASSERT(luaH_mainposition(t, key) == mp, "cannot change hash");
   }
+  t->lsizenode = cast(lu_byte, lsize);
+  t->firstfree = gnode(t, size-1);  /* first free position to be used */
 }
 
 
-static void setnodevector (lua_State *L, Hash *t, lint32 size) {
+static void resize (lua_State *L, Table *t, int nasize, int nhsize) {
   int i;
-  if (size > MAX_INT)
-    lua_error(L, "table overflow");
-  t->node = luaM_newvector(L, size, Node);
-  for (i=0; i<(int)size; i++) {
-    ttype(&t->node[i].key) = ttype(&t->node[i].val) = LUA_TNIL;
-    t->node[i].next = NULL;
+  int oldasize = t->sizearray;
+  int oldhsize = t->lsizenode;
+  Node *nold;
+  Node temp[1];
+  if (oldhsize)
+    nold = t->node;  /* save old hash ... */
+  else {  /* old hash is `dummynode' */
+    lua_assert(t->node == G(L)->dummynode);
+    temp[0] = t->node[0];  /* copy it to `temp' */
+    nold = temp;
+    setnilvalue(gkey(G(L)->dummynode));  /* restate invariant */
+    setnilvalue(gval(G(L)->dummynode));
+    lua_assert(G(L)->dummynode->next == NULL);
+  }
+  if (nasize > oldasize)  /* array part must grow? */
+    setarrayvector(L, t, nasize);
+  /* create new hash part with appropriate size */
+  setnodevector(L, t, nhsize);  
+  /* re-insert elements */
+  if (nasize < oldasize) {  /* array part must shrink? */
+    t->sizearray = nasize;
+    /* re-insert elements from vanishing slice */
+    for (i=nasize; i<oldasize; i++) {
+      if (!ttisnil(&t->array[i]))
+        setobjt2t(luaH_setnum(L, t, i+1), &t->array[i]);
+    }
+    /* shrink array */
+    luaM_reallocvector(L, t->array, oldasize, nasize, TObject);
   }
-  L->nblocks += gcsize(L, size) - gcsize(L, t->size);
-  t->size = size;
-  t->firstfree = &t->node[size-1];  /* first free position to be used */
+  /* re-insert elements in hash part */
+  for (i = twoto(oldhsize) - 1; i >= 0; i--) {
+    Node *old = nold+i;
+    if (!ttisnil(gval(old)))
+      setobjt2t(luaH_set(L, t, gkey(old)), gval(old));
+  }
+  if (oldhsize)
+    luaM_freearray(L, nold, twoto(oldhsize), Node);  /* free old array */
 }
 
 
-Hash *luaH_new (lua_State *L, int size) {
-  Hash *t = luaM_new(L, Hash);
-  t->htag = TagDefault;
-  t->next = L->roottable;
-  L->roottable = t;
-  t->mark = t;
-  t->size = 0;
-  L->nblocks += gcsize(L, 0);
-  t->node = NULL;
-  setnodevector(L, t, luaO_power2(size));
-  return t;
+static void rehash (lua_State *L, Table *t) {
+  int nasize, nhsize;
+  numuse(t, &nasize, &nhsize);  /* compute new sizes for array and hash parts */
+  resize(L, t, nasize, luaO_log2(nhsize)+1);
 }
 
 
-void luaH_free (lua_State *L, Hash *t) {
-  L->nblocks -= gcsize(L, t->size);
-  luaM_free(L, t->node);
-  luaM_free(L, t);
+
+/*
+** }=============================================================
+*/
+
+
+Table *luaH_new (lua_State *L, int narray, int lnhash) {
+  Table *t = luaM_new(L, Table);
+  luaC_link(L, valtogco(t), LUA_TTABLE);
+  t->metatable = hvalue(defaultmeta(L));
+  t->flags = cast(lu_byte, ~0);
+  /* temporary values (kept only if some malloc fails) */
+  t->array = NULL;
+  t->sizearray = 0;
+  t->lsizenode = 0;
+  t->node = NULL;
+  setarrayvector(L, t, narray);
+  setnodevector(L, t, lnhash);
+  return t;
 }
 
 
-static int numuse (const Hash *t) {
-  Node *v = t->node;
-  int size = t->size;
-  int realuse = 0;
-  int i;
-  for (i=0; i<size; i++) {
-    if (ttype(&v[i].val) != LUA_TNIL)
-      realuse++;
-  }
-  return realuse;
+void luaH_free (lua_State *L, Table *t) {
+  if (t->lsizenode)
+    luaM_freearray(L, t->node, sizenode(t), Node);
+  luaM_freearray(L, t->array, t->sizearray, TObject);
+  luaM_freelem(L, t);
 }
 
 
-static void rehash (lua_State *L, Hash *t) {
-  int oldsize = t->size;
-  Node *nold = t->node;
-  int nelems = numuse(t);
-  int i;
-  LUA_ASSERT(nelems<=oldsize, "wrong count");
-  if (nelems >= oldsize-oldsize/4)  /* using more than 3/4? */
-    setnodevector(L, t, (lint32)oldsize*2);
-  else if (nelems <= oldsize/4 &&  /* less than 1/4? */
-           oldsize > MINPOWER2)
-    setnodevector(L, t, oldsize/2);
-  else
-    setnodevector(L, t, oldsize);
-  for (i=0; i<oldsize; i++) {
-    Node *old = nold+i;
-    if (ttype(&old->val) != LUA_TNIL)
-      *luaH_set(L, t, &old->key) = old->val;
+#if 0
+/*
+** try to remove an element from a hash table; cannot move any element
+** (because gc can call `remove' during a table traversal)
+*/
+void luaH_remove (Table *t, Node *e) {
+  Node *mp = luaH_mainposition(t, gkey(e));
+  if (e != mp) {  /* element not in its main position? */
+    while (mp->next != e) mp = mp->next;  /* find previous */
+    mp->next = e->next;  /* remove `e' from its list */
+  }
+  else {
+    if (e->next != NULL) ??
   }
-  luaM_free(L, nold);  /* free old array */
+  lua_assert(ttisnil(gval(node)));
+  setnilvalue(gkey(e));  /* clear node `e' */
+  e->next = NULL;
 }
+#endif
 
 
 /*
-** inserts a key into a hash table; first, check whether key is
-** already present; if not, check whether key's main position is free;
-** if not, check whether colliding node is in its main position or not;
-** if it is not, move colliding node to an empty place and put new key
-** in its main position; otherwise (colliding node is in its main position),
-** new key goes to an empty position.
+** inserts a new key into a hash table; first, check whether key's main 
+** position is free. If not, check whether colliding node is in its main 
+** position or not: if it is not, move colliding node to an empty place and 
+** put new key in its main position; otherwise (colliding node is in its main 
+** position), new key goes to an empty position. 
 */
-TObject *luaH_set (lua_State *L, Hash *t, const TObject *key) {
+static TObject *newkey (lua_State *L, Table *t, const TObject *key) {
+  TObject *val;
   Node *mp = luaH_mainposition(t, key);
-  Node *n = mp;
-  if (!mp)
-    lua_error(L, "table index is nil");
-  do {  /* check whether `key' is somewhere in the chain */
-    if (luaO_equalObj(key, &n->key))
-      return &n->val;  /* that's all */
-    else n = n->next;
-  } while (n);
-  /* `key' not found; must insert it */
-  if (ttype(&mp->key) != LUA_TNIL) {  /* main position is not free? */
-    Node *othern;  /* main position of colliding node */
-    n = t->firstfree;  /* get a free place */
-    /* is colliding node out of its main position? (can only happens if
-       its position is after "firstfree") */
-    if (mp > n && (othern=luaH_mainposition(t, &mp->key)) != mp) {
+  if (!ttisnil(gval(mp))) {  /* main position is not free? */
+    Node *othern = luaH_mainposition(t, gkey(mp));  /* `mp' of colliding node */
+    Node *n = t->firstfree;  /* get a free place */
+    if (othern != mp) {  /* is colliding node out of its main position? */
       /* yes; move colliding node into free position */
       while (othern->next != mp) othern = othern->next;  /* find previous */
       othern->next = n;  /* redo the chain with `n' in place of `mp' */
       *n = *mp;  /* copy colliding node into free pos. (mp->next also goes) */
       mp->next = NULL;  /* now `mp' is free */
+      setnilvalue(gval(mp));
     }
     else {  /* colliding node is in its own main position */
       /* new node will go into free position */
@@ -267,37 +397,113 @@ TObject *luaH_set (lua_State *L, Hash *t, const TObject *key) {
       mp = n;
     }
   }
-  mp->key = *key;
+  setobj2t(gkey(mp), key);  /* write barrier */
+  lua_assert(ttisnil(gval(mp)));
   for (;;) {  /* correct `firstfree' */
-    if (ttype(&t->firstfree->key) == LUA_TNIL)
-      return &mp->val;  /* OK; table still has a free place */
+    if (ttisnil(gkey(t->firstfree)))
+      return gval(mp);  /* OK; table still has a free place */
     else if (t->firstfree == t->node) break;  /* cannot decrement from here */
     else (t->firstfree)--;
   }
-  rehash(L, t);  /* no more free places */
-  return luaH_set(L, t, key);  /* `rehash' invalidates this insertion */
+  /* no more free places; must create one */
+  setbvalue(gval(mp), 0);  /* avoid new key being removed */
+  rehash(L, t);  /* grow table */
+  val = cast(TObject *, luaH_get(t, key));  /* get new position */
+  lua_assert(ttisboolean(val));
+  setnilvalue(val);
+  return val;
+}
+
+
+/*
+** generic search function
+*/
+static const TObject *luaH_getany (Table *t, const TObject *key) {
+  if (ttisnil(key)) return &luaO_nilobject;
+  else {
+    Node *n = luaH_mainposition(t, key);
+    do {  /* check whether `key' is somewhere in the chain */
+      if (luaO_rawequalObj(gkey(n), key)) return gval(n);  /* that's it */
+      else n = n->next;
+    } while (n);
+    return &luaO_nilobject;
+  }
 }
 
 
-TObject *luaH_setint (lua_State *L, Hash *t, int key) {
-  TObject index;
-  ttype(&index) = LUA_TNUMBER;
-  nvalue(&index) = key;
-  return luaH_set(L, t, &index);
+/*
+** search function for integers
+*/
+const TObject *luaH_getnum (Table *t, int key) {
+  if (1 <= key && key <= t->sizearray)
+    return &t->array[key-1];
+  else {
+    lua_Number nk = cast(lua_Number, key);
+    Node *n = hashnum(t, nk);
+    do {  /* check whether `key' is somewhere in the chain */
+      if (ttisnumber(gkey(n)) && nvalue(gkey(n)) == nk)
+        return gval(n);  /* that's it */
+      else n = n->next;
+    } while (n);
+    return &luaO_nilobject;
+  }
 }
 
 
-void luaH_setstrnum (lua_State *L, Hash *t, TString *key, Number val) {
-  TObject *value, index;
-  ttype(&index) = LUA_TSTRING;
-  tsvalue(&index) = key;
-  value = luaH_set(L, t, &index);
-  ttype(value) = LUA_TNUMBER;
-  nvalue(value) = val;
+/*
+** search function for strings
+*/
+const TObject *luaH_getstr (Table *t, TString *key) {
+  Node *n = hashstr(t, key);
+  do {  /* check whether `key' is somewhere in the chain */
+    if (ttisstring(gkey(n)) && tsvalue(gkey(n)) == key)
+      return gval(n);  /* that's it */
+    else n = n->next;
+  } while (n);
+  return &luaO_nilobject;
 }
 
 
-const TObject *luaH_getglobal (lua_State *L, const char *name) {
-  return luaH_getstr(L->gt, luaS_new(L, name));
+/*
+** main search function
+*/
+const TObject *luaH_get (Table *t, const TObject *key) {
+  switch (ttype(key)) {
+    case LUA_TSTRING: return luaH_getstr(t, tsvalue(key));
+    case LUA_TNUMBER: {
+      int k;
+      lua_number2int(k, (nvalue(key)));
+      if (cast(lua_Number, k) == nvalue(key))  /* is an integer index? */
+        return luaH_getnum(t, k);  /* use specialized version */
+      /* else go through */
+    }
+    default: return luaH_getany(t, key);
+  }
+}
+
+
+TObject *luaH_set (lua_State *L, Table *t, const TObject *key) {
+  const TObject *p = luaH_get(t, key);
+  t->flags = 0;
+  if (p != &luaO_nilobject)
+    return cast(TObject *, p);
+  else {
+    if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+    else if (ttisnumber(key) && nvalue(key) != nvalue(key))
+      luaG_runerror(L, "table index is NaN");
+    return newkey(L, t, key);
+  }
+}
+
+
+TObject *luaH_setnum (lua_State *L, Table *t, int key) {
+  const TObject *p = luaH_getnum(t, key);
+  if (p != &luaO_nilobject)
+    return cast(TObject *, p);
+  else {
+    TObject k;
+    setnvalue(&k, cast(lua_Number, key));
+    return newkey(L, t, &k);
+  }
 }
 
diff --git a/src/ltable.h b/src/ltable.h
index 8ee41a81..3d4d753c 100644
--- a/src/ltable.h
+++ b/src/ltable.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.h,v 1.24 2000/08/31 14:08:27 roberto Exp $
+** $Id: ltable.h,v 1.44 2003/03/18 12:50:04 roberto Exp $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -10,25 +10,22 @@
 #include "lobject.h"
 
 
-#define node(t,i)	(&(t)->node[i])
-#define key(n)		(&(n)->key)
-#define val(n)		(&(n)->val)
+#define gnode(t,i)	(&(t)->node[i])
+#define gkey(n)		(&(n)->i_key)
+#define gval(n)		(&(n)->i_val)
 
-Hash *luaH_new (lua_State *L, int nhash);
-void luaH_free (lua_State *L, Hash *t);
-const TObject *luaH_get (lua_State *L, const Hash *t, const TObject *key);
-const TObject *luaH_getnum (const Hash *t, Number key);
-const TObject *luaH_getstr (const Hash *t, TString *key);
-void luaH_remove (Hash *t, TObject *key);
-TObject *luaH_set (lua_State *L, Hash *t, const TObject *key);
-Node * luaH_next (lua_State *L, const Hash *t, const TObject *r);
-TObject *luaH_setint (lua_State *L, Hash *t, int key);
-void luaH_setstrnum (lua_State *L, Hash *t, TString *key, Number val);
-unsigned long luaH_hash (lua_State *L, const TObject *key);
-const TObject *luaH_getglobal (lua_State *L, const char *name);
+
+const TObject *luaH_getnum (Table *t, int key);
+TObject *luaH_setnum (lua_State *L, Table *t, int key);
+const TObject *luaH_getstr (Table *t, TString *key);
+const TObject *luaH_get (Table *t, const TObject *key);
+TObject *luaH_set (lua_State *L, Table *t, const TObject *key);
+Table *luaH_new (lua_State *L, int narray, int lnhash);
+void luaH_free (lua_State *L, Table *t);
+int luaH_next (lua_State *L, Table *t, StkId key);
 
 /* exported only for debugging */
-Node *luaH_mainposition (const Hash *t, const TObject *key);
+Node *luaH_mainposition (const Table *t, const TObject *key);
 
 
 #endif
diff --git a/src/ltests.c b/src/ltests.c
index c27c7c81..649b14e0 100644
--- a/src/ltests.c
+++ b/src/ltests.c
@@ -1,15 +1,17 @@
 /*
-** $Id: ltests.c,v 1.54 2000/10/31 13:10:24 roberto Exp $
+** $Id: ltests.c,v 1.158 2003/04/07 14:35:00 roberto Exp $
 ** Internal Module for Debugging of the Lua Implementation
 ** See Copyright Notice in lua.h
 */
 
 
 #include <ctype.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#define ltests_c
 
 #include "lua.h"
 
@@ -24,12 +26,9 @@
 #include "lstate.h"
 #include "lstring.h"
 #include "ltable.h"
-#include "luadebug.h"
 #include "lualib.h"
 
 
-void luaB_opentests (lua_State *L);
-
 
 /*
 ** The whole module only makes sense with LUA_DEBUG on
@@ -37,88 +36,187 @@ void luaB_opentests (lua_State *L);
 #ifdef LUA_DEBUG
 
 
+#define lua_pushintegral(L,i)	lua_pushnumber(L, cast(lua_Number, (i)))
+
+
+static lua_State *lua_state = NULL;
+
+int islocked = 0;
+
+
+#define func_at(L,k)	(L->ci->base+(k) - 1)
+
 
 static void setnameval (lua_State *L, const char *name, int val) {
   lua_pushstring(L, name);
-  lua_pushnumber(L, val);
+  lua_pushintegral(L, val);
   lua_settable(L, -3);
 }
 
 
 /*
+** {======================================================================
+** Controlled version for realloc.
+** =======================================================================
+*/
+
+#define MARK		0x55  /* 01010101 (a nice pattern) */
+
+#ifndef EXTERNMEMCHECK
+/* full memory check */
+#define HEADER	(sizeof(L_Umaxalign)) /* ensures maximum alignment for HEADER */
+#define MARKSIZE	16  /* size of marks after each block */
+#define blockhead(b)	(cast(char *, b) - HEADER)
+#define setsize(newblock, size)	(*cast(size_t *, newblock) = size)
+#define checkblocksize(b, size) (size == (*cast(size_t *, blockhead(b))))
+#define fillmem(mem,size)	memset(mem, -MARK, size)
+#else
+/* external memory check: don't do it twice */
+#define HEADER		0
+#define MARKSIZE	0
+#define blockhead(b)	(b)
+#define setsize(newblock, size)	/* empty */
+#define checkblocksize(b,size)	(1)
+#define fillmem(mem,size)	/* empty */
+#endif
+
+unsigned long memdebug_numblocks = 0;
+unsigned long memdebug_total = 0;
+unsigned long memdebug_maxmem = 0;
+unsigned long memdebug_memlimit = ULONG_MAX;
+
+
+static void *checkblock (void *block, size_t size) {
+  void *b = blockhead(block);
+  int i;
+  for (i=0;i<MARKSIZE;i++)
+    lua_assert(*(cast(char *, b)+HEADER+size+i) == MARK+i); /* corrupted block? */
+  return b;
+}
+
+
+static void freeblock (void *block, size_t size) {
+  if (block) {
+    lua_assert(checkblocksize(block, size));
+    block = checkblock(block, size);
+    fillmem(block, size+HEADER+MARKSIZE);  /* erase block */
+    free(block);  /* free original block */
+    memdebug_numblocks--;
+    memdebug_total -= size;
+  }
+}
+
+
+void *debug_realloc (void *block, size_t oldsize, size_t size) {
+  lua_assert(oldsize == 0 || checkblocksize(block, oldsize));
+  /* ISO does not specify what realloc(NULL, 0) does */
+  lua_assert(block != NULL || size > 0);
+  if (size == 0) {
+    freeblock(block, oldsize);
+    return NULL;
+  }
+  else if (size > oldsize && memdebug_total+size-oldsize > memdebug_memlimit)
+    return NULL;  /* to test memory allocation errors */
+  else {
+    void *newblock;
+    int i;
+    size_t realsize = HEADER+size+MARKSIZE;
+    size_t commonsize = (oldsize < size) ? oldsize : size;
+    if (realsize < size) return NULL;  /* overflow! */
+    newblock = malloc(realsize);  /* alloc a new block */
+    if (newblock == NULL) return NULL;
+    if (block) {
+      memcpy(cast(char *, newblock)+HEADER, block, commonsize);
+      freeblock(block, oldsize);  /* erase (and check) old copy */
+    }
+    /* initialize new part of the block with something `weird' */
+    fillmem(cast(char *, newblock)+HEADER+commonsize, size-commonsize);
+    memdebug_total += size;
+    if (memdebug_total > memdebug_maxmem)
+      memdebug_maxmem = memdebug_total;
+    memdebug_numblocks++;
+    setsize(newblock, size);
+    for (i=0;i<MARKSIZE;i++)
+      *(cast(char *, newblock)+HEADER+size+i) = cast(char, MARK+i);
+    return cast(char *, newblock)+HEADER;
+  }
+}
+
+
+/* }====================================================================== */
+
+
+
+/*
 ** {======================================================
 ** Disassembler
 ** =======================================================
 */
 
 
-static const char *const instrname[NUM_OPCODES] = {
-  "END", "RETURN", "CALL", "TAILCALL", "PUSHNIL", "POP", "PUSHINT", 
-  "PUSHSTRING", "PUSHNUM", "PUSHNEGNUM", "PUSHUPVALUE", "GETLOCAL", 
-  "GETGLOBAL", "GETTABLE", "GETDOTTED", "GETINDEXED", "PUSHSELF", 
-  "CREATETABLE", "SETLOCAL", "SETGLOBAL", "SETTABLE", "SETLIST", "SETMAP", 
-  "ADD", "ADDI", "SUB", "MULT", "DIV", "POW", "CONCAT", "MINUS", "NOT", 
-  "JMPNE", "JMPEQ", "JMPLT", "JMPLE", "JMPGT", "JMPGE", "JMPT", "JMPF", 
-  "JMPONT", "JMPONF", "JMP", "PUSHNILJMP", "FORPREP", "FORLOOP", "LFORPREP", 
-  "LFORLOOP", "CLOSURE"
-};
-
-
-static int pushop (lua_State *L, Proto *p, int pc) {
-  char buff[100];
+static char *buildop (Proto *p, int pc, char *buff) {
   Instruction i = p->code[pc];
   OpCode o = GET_OPCODE(i);
-  const char *name = instrname[o];
-  sprintf(buff, "%5d - ", luaG_getline(p->lineinfo, pc, 1, NULL));
-  switch ((enum Mode)luaK_opproperties[o].mode) {  
-    case iO:
-      sprintf(buff+8, "%-12s", name);
-      break;
-    case iU:
-      sprintf(buff+8, "%-12s%4u", name, GETARG_U(i));
+  const char *name = luaP_opnames[o];
+  int line = getline(p, pc);
+  sprintf(buff, "(%4d) %4d - ", line, pc);
+  switch (getOpMode(o)) {  
+    case iABC:
+      sprintf(buff+strlen(buff), "%-12s%4d %4d %4d", name,
+              GETARG_A(i), GETARG_B(i), GETARG_C(i));
       break;
-    case iS:
-      sprintf(buff+8, "%-12s%4d", name, GETARG_S(i));
+    case iABx:
+      sprintf(buff+strlen(buff), "%-12s%4d %4d", name, GETARG_A(i), GETARG_Bx(i));
       break;
-    case iAB:
-      sprintf(buff+8, "%-12s%4d %4d", name, GETARG_A(i), GETARG_B(i));
+    case iAsBx:
+      sprintf(buff+strlen(buff), "%-12s%4d %4d", name, GETARG_A(i), GETARG_sBx(i));
       break;
   }
-  lua_pushstring(L, buff);
-  return (o != OP_END);
+  return buff;
 }
 
 
+#if 0
+void luaI_printcode (Proto *pt, int size) {
+  int pc;
+  for (pc=0; pc<size; pc++) {
+    char buff[100];
+    printf("%s\n", buildop(pt, pc, buff));
+  }
+  printf("-------\n");
+}
+#endif
+
+
 static int listcode (lua_State *L) {
   int pc;
   Proto *p;
-  int res;
-  luaL_arg_check(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
+  luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
                  1, "Lua function expected");
-  p = clvalue(luaA_index(L, 1))->f.l;
+  p = clvalue(func_at(L, 1))->l.p;
   lua_newtable(L);
   setnameval(L, "maxstack", p->maxstacksize);
   setnameval(L, "numparams", p->numparams);
-  pc = 0;
-  do {
-    lua_pushnumber(L, pc+1);
-    res = pushop(L, p, pc++);
+  for (pc=0; pc<p->sizecode; pc++) {
+    char buff[100];
+    lua_pushintegral(L, pc+1);
+    lua_pushstring(L, buildop(p, pc, buff));
     lua_settable(L, -3);
-  } while (res);
+  }
   return 1;
 }
 
 
-static int liststrings (lua_State *L) {
+static int listk (lua_State *L) {
   Proto *p;
   int i;
-  luaL_arg_check(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
+  luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
                  1, "Lua function expected");
-  p = clvalue(luaA_index(L, 1))->f.l;
+  p = clvalue(func_at(L, 1))->l.p;
   lua_newtable(L);
-  for (i=0; i<p->nkstr; i++) {
-    lua_pushnumber(L, i+1);
-    lua_pushstring(L, p->kstr[i]->str);
+  for (i=0; i<p->sizek; i++) {
+    lua_pushintegral(L, i+1);
+    luaA_pushobject(L, p->k+i);
     lua_settable(L, -3);
   }
   return 1;
@@ -127,12 +225,12 @@ static int liststrings (lua_State *L) {
 
 static int listlocals (lua_State *L) {
   Proto *p;
-  int pc = luaL_check_int(L, 2) - 1;
+  int pc = luaL_checkint(L, 2) - 1;
   int i = 0;
   const char *name;
-  luaL_arg_check(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
+  luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1),
                  1, "Lua function expected");
-  p = clvalue(luaA_index(L, 1))->f.l;
+  p = clvalue(func_at(L, 1))->l.p;
   while ((name = luaF_getlocalname(p, ++i, pc)) != NULL)
     lua_pushstring(L, name);
   return i-1;
@@ -142,96 +240,107 @@ static int listlocals (lua_State *L) {
 
 
 
+
 static int get_limits (lua_State *L) {
   lua_newtable(L);
   setnameval(L, "BITS_INT", BITS_INT);
   setnameval(L, "LFPF", LFIELDS_PER_FLUSH);
-  setnameval(L, "MAXARG_A", MAXARG_A);
-  setnameval(L, "MAXARG_B", MAXARG_B);
-  setnameval(L, "MAXARG_S", MAXARG_S);
-  setnameval(L, "MAXARG_U", MAXARG_U);
-  setnameval(L, "MAXLOCALS", MAXLOCALS);
+  setnameval(L, "MAXVARS", MAXVARS);
   setnameval(L, "MAXPARAMS", MAXPARAMS);
   setnameval(L, "MAXSTACK", MAXSTACK);
   setnameval(L, "MAXUPVALUES", MAXUPVALUES);
-  setnameval(L, "MAXVARSLH", MAXVARSLH);
-  setnameval(L, "RFPF", RFIELDS_PER_FLUSH);
-  setnameval(L, "SIZE_A", SIZE_A);
-  setnameval(L, "SIZE_B", SIZE_B);
-  setnameval(L, "SIZE_OP", SIZE_OP);
-  setnameval(L, "SIZE_U", SIZE_U);
   return 1;
 }
 
 
 static int mem_query (lua_State *L) {
-  if (lua_isnull(L, 1)) {
-    lua_pushnumber(L, memdebug_total);
-    lua_pushnumber(L, memdebug_numblocks);
-    lua_pushnumber(L, memdebug_maxmem);
+  if (lua_isnone(L, 1)) {
+    lua_pushintegral(L, memdebug_total);
+    lua_pushintegral(L, memdebug_numblocks);
+    lua_pushintegral(L, memdebug_maxmem);
     return 3;
   }
   else {
-    memdebug_memlimit = luaL_check_int(L, 1);
+    memdebug_memlimit = luaL_checkint(L, 1);
     return 0;
   }
 }
 
 
 static int hash_query (lua_State *L) {
-  if (lua_isnull(L, 2)) {
-    luaL_arg_check(L, lua_tag(L, 1) == LUA_TSTRING, 1, "string expected");
-    lua_pushnumber(L, tsvalue(luaA_index(L, 1))->u.s.hash);
+  if (lua_isnone(L, 2)) {
+    luaL_argcheck(L, lua_type(L, 1) == LUA_TSTRING, 1, "string expected");
+    lua_pushintegral(L, tsvalue(func_at(L, 1))->tsv.hash);
   }
   else {
-    Hash *t;
+    TObject *o = func_at(L, 1);
+    Table *t;
     luaL_checktype(L, 2, LUA_TTABLE);
-    t = hvalue(luaA_index(L, 2));
-    lua_pushnumber(L, luaH_mainposition(t, luaA_index(L, 1)) - t->node);
+    t = hvalue(func_at(L, 2));
+    lua_pushintegral(L, luaH_mainposition(t, o) - t->node);
   }
   return 1;
 }
 
 
+static int stacklevel (lua_State *L) {
+  unsigned long a = 0;
+  lua_pushintegral(L, (int)(L->top - L->stack));
+  lua_pushintegral(L, (int)(L->stack_last - L->stack));
+  lua_pushintegral(L, (int)(L->ci - L->base_ci));
+  lua_pushintegral(L, (int)(L->end_ci - L->base_ci));
+  lua_pushintegral(L, (unsigned long)&a);
+  return 5;
+}
+
+
 static int table_query (lua_State *L) {
-  const Hash *t;
-  int i = luaL_opt_int(L, 2, -1);
+  const Table *t;
+  int i = luaL_optint(L, 2, -1);
   luaL_checktype(L, 1, LUA_TTABLE);
-  t = hvalue(luaA_index(L, 1));
+  t = hvalue(func_at(L, 1));
   if (i == -1) {
-    lua_pushnumber(L, t->size);
-    lua_pushnumber(L, t->firstfree - t->node);
-    return 2;
+    lua_pushintegral(L, t->sizearray);
+    lua_pushintegral(L, sizenode(t));
+    lua_pushintegral(L, t->firstfree - t->node);
   }
-  else if (i < t->size) {
-    luaA_pushobject(L, &t->node[i].key);
-    luaA_pushobject(L, &t->node[i].val);
-    if (t->node[i].next) {
-      lua_pushnumber(L, t->node[i].next - t->node);
-      return 3;
+  else if (i < t->sizearray) {
+    lua_pushintegral(L, i);
+    luaA_pushobject(L, &t->array[i]);
+    lua_pushnil(L); 
+  }
+  else if ((i -= t->sizearray) < sizenode(t)) {
+    if (!ttisnil(gval(gnode(t, i))) ||
+        ttisnil(gkey(gnode(t, i))) ||
+        ttisnumber(gkey(gnode(t, i)))) {
+      luaA_pushobject(L, gkey(gnode(t, i)));
     }
     else
-      return 2;
+      lua_pushstring(L, "<undef>");
+    luaA_pushobject(L, gval(gnode(t, i)));
+    if (t->node[i].next)
+      lua_pushintegral(L, t->node[i].next - t->node);
+    else
+      lua_pushnil(L);
   }
-  return 0;
+  return 3;
 }
 
 
 static int string_query (lua_State *L) {
-  stringtable *tb = (*luaL_check_string(L, 1) == 's') ? &L->strt : &L->udt;
-  int s = luaL_opt_int(L, 2, 0) - 1;
+  stringtable *tb = &G(L)->strt;
+  int s = luaL_optint(L, 2, 0) - 1;
   if (s==-1) {
-    lua_pushnumber(L ,tb->nuse);
-    lua_pushnumber(L ,tb->size);
+    lua_pushintegral(L ,tb->nuse);
+    lua_pushintegral(L ,tb->size);
     return 2;
   }
   else if (s < tb->size) {
-    TString *ts;
+    GCObject *ts;
     int n = 0;
-    for (ts = tb->hash[s]; ts; ts = ts->nexthash) {
-      ttype(L->top) = LUA_TSTRING;
-      tsvalue(L->top) = ts;
-      incr_top;
+    for (ts = tb->hash[s]; ts; ts = ts->gch.next) {
+      setsvalue2s(L->top, gcotots(ts));
+      incr_top(L);
       n++;
     }
     return n;
@@ -241,111 +350,193 @@ static int string_query (lua_State *L) {
 
 
 static int tref (lua_State *L) {
+  int level = lua_gettop(L);
+  int lock = luaL_optint(L, 2, 1);
   luaL_checkany(L, 1);
   lua_pushvalue(L, 1);
-  lua_pushnumber(L, lua_ref(L, luaL_opt_int(L, 2, 1)));
+  lua_pushintegral(L, lua_ref(L, lock));
+  assert(lua_gettop(L) == level+1);  /* +1 for result */
   return 1;
 }
 
 static int getref (lua_State *L) {
-  if (lua_getref(L, luaL_check_int(L, 1)))
-    return 1;
-  else
-    return 0;
+  int level = lua_gettop(L);
+  lua_getref(L, luaL_checkint(L, 1));
+  assert(lua_gettop(L) == level+1);
+  return 1;
 }
 
 static int unref (lua_State *L) {
-  lua_unref(L, luaL_check_int(L, 1));
+  int level = lua_gettop(L);
+  lua_unref(L, luaL_checkint(L, 1));
+  assert(lua_gettop(L) == level);
   return 0;
 }
 
+static int metatable (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (lua_isnone(L, 2)) {
+    if (lua_getmetatable(L, 1) == 0)
+      lua_pushnil(L);
+  }
+  else {
+    lua_settop(L, 2);
+    luaL_checktype(L, 2, LUA_TTABLE);
+    lua_setmetatable(L, 1);
+  }
+  return 1;
+}
+
+
+static int upvalue (lua_State *L) {
+  int n = luaL_checkint(L, 2);
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  if (lua_isnone(L, 3)) {
+    const char *name = lua_getupvalue(L, 1, n);
+    if (name == NULL) return 0;
+    lua_pushstring(L, name);
+    return 2;
+  }
+  else {
+    const char *name = lua_setupvalue(L, 1, n);
+    lua_pushstring(L, name);
+    return 1;
+  }
+}
+
+
 static int newuserdata (lua_State *L) {
-  if (lua_isnumber(L, 2))
-    lua_pushusertag(L, (void *)luaL_check_int(L, 1), luaL_check_int(L, 2));
-  else
-    lua_newuserdata(L, luaL_check_int(L, 1));
+  size_t size = luaL_checkint(L, 1);
+  char *p = cast(char *, lua_newuserdata(L, size));
+  while (size--) *p++ = '\0';
+  return 1;
+}
+
+
+static int pushuserdata (lua_State *L) {
+  lua_pushlightuserdata(L, cast(void *, luaL_checkint(L, 1)));
   return 1;
 }
 
+
 static int udataval (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TUSERDATA);
-  lua_pushnumber(L, (int)lua_touserdata(L, 1));
+  lua_pushintegral(L, cast(int, lua_touserdata(L, 1)));
+  return 1;
+}
+
+
+static int doonnewstack (lua_State *L) {
+  lua_State *L1 = lua_newthread(L);
+  size_t l;
+  const char *s = luaL_checklstring(L, 1, &l);
+  int status = luaL_loadbuffer(L1, s, l, s);
+  if (status == 0)
+    status = lua_pcall(L1, 0, 0, 0);
+  lua_pushintegral(L, status);
+  return 1;
+}
+
+
+static int s2d (lua_State *L) {
+  lua_pushnumber(L, *cast(const double *, luaL_checkstring(L, 1)));
+  return 1;
+}
+
+static int d2s (lua_State *L) {
+  double d = luaL_checknumber(L, 1);
+  lua_pushlstring(L, cast(char *, &d), sizeof(d));
   return 1;
 }
 
+
 static int newstate (lua_State *L) {
-  lua_State *L1 = lua_open(luaL_check_int(L, 1));
-  if (L1)
-    lua_pushuserdata(L, L1);
+  lua_State *L1 = lua_open();
+  if (L1) {
+    lua_userstateopen(L1);  /* init lock */
+    lua_pushintegral(L, (unsigned long)L1);
+  }
   else
     lua_pushnil(L);
   return 1;
 }
 
+
 static int loadlib (lua_State *L) {
-  lua_State *L1 = (lua_State *)lua_touserdata(L, 1);
-  switch (*luaL_check_string(L, 2)) {
-    case 'm': lua_mathlibopen(L1); break;
-    case 's': lua_strlibopen(L1); break;
-    case 'i': lua_iolibopen(L1); break;
-    case 'd': lua_dblibopen(L1); break;
-    case 'b': lua_baselibopen(L1); break;
-    default: luaL_argerror(L, 2, "invalid option");
-  }
+  static const luaL_reg libs[] = {
+    {"mathlibopen", luaopen_math},
+    {"strlibopen", luaopen_string},
+    {"iolibopen", luaopen_io},
+    {"tablibopen", luaopen_table},
+    {"dblibopen", luaopen_debug},
+    {"baselibopen", luaopen_base},
+    {NULL, NULL}
+  };
+  lua_State *L1 = cast(lua_State *,
+                       cast(unsigned long, luaL_checknumber(L, 1)));
+  lua_pushvalue(L1, LUA_GLOBALSINDEX);
+  luaL_openlib(L1, NULL, libs, 0);
   return 0;
 }
 
 static int closestate (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TUSERDATA);
-  lua_close((lua_State *)lua_touserdata(L, 1));
+  lua_State *L1 = cast(lua_State *, cast(unsigned long, luaL_checknumber(L, 1)));
+  lua_close(L1);
+  lua_unlock(L);  /* close cannot unlock that */
   return 0;
 }
 
 static int doremote (lua_State *L) {
-  lua_State *L1;
-  const char *code = luaL_check_string(L, 2);
+  lua_State *L1 = cast(lua_State *,cast(unsigned long,luaL_checknumber(L, 1)));
+  size_t lcode;
+  const char *code = luaL_checklstring(L, 2, &lcode);
   int status;
-  luaL_checktype(L, 1, LUA_TUSERDATA);
-  L1 = (lua_State *)lua_touserdata(L, 1);
-  status = lua_dostring(L1, code);
+  lua_settop(L1, 0);
+  status = luaL_loadbuffer(L1, code, lcode, code);
+  if (status == 0)
+    status = lua_pcall(L1, 0, LUA_MULTRET, 0);
   if (status != 0) {
     lua_pushnil(L);
-    lua_pushnumber(L, status);
-    return 2;
+    lua_pushintegral(L, status);
+    lua_pushstring(L, lua_tostring(L1, -1));
+    return 3;
   }
   else {
     int i = 0;
-    while (!lua_isnull(L1, ++i))
+    while (!lua_isnone(L1, ++i))
       lua_pushstring(L, lua_tostring(L1, i));
+    lua_pop(L1, i-1);
     return i-1;
   }
 }
 
-static int settagmethod (lua_State *L) {
-  int tag = luaL_check_int(L, 1);
-  const char *event = luaL_check_string(L, 2);
-  luaL_checkany(L, 3);
-  lua_gettagmethod(L, tag, event);
-  lua_pushvalue(L, 3);
-  lua_settagmethod(L, tag, event);
+
+static int log2_aux (lua_State *L) {
+  lua_pushintegral(L, luaO_log2(luaL_checkint(L, 1)));
   return 1;
 }
 
-static int pushbool (lua_State *L, int b) {
-  if (b) lua_pushnumber(L, 1);
-  else lua_pushnil(L);
-  return 1;
+static int int2fb_aux (lua_State *L) {
+  int b = luaO_int2fb(luaL_checkint(L, 1));
+  lua_pushintegral(L, b);
+  lua_pushintegral(L, fb2int(b));
+  return 2;
 }
 
-static int equal (lua_State *L) {
-  return pushbool(L, lua_equal(L, 1, 2));
+
+static int test_do (lua_State *L) {
+  const char *p = luaL_checkstring(L, 1);
+  if (*p == '@')
+    lua_dofile(L, p+1);
+  else
+    lua_dostring(L, p);
+  return lua_gettop(L);
 }
 
-  
+
 
 /*
 ** {======================================================
-** function to test the API with C. It interprets a kind of "assembler"
+** function to test the API with C. It interprets a kind of assembler
 ** language with calls to the API, so the test can be driven by Lua code
 ** =======================================================
 */
@@ -356,12 +547,12 @@ static void skip (const char **pc) {
   while (**pc != '\0' && strchr(delimits, **pc)) (*pc)++;
 }
 
-static int getnum (lua_State *L, const char **pc) {
+static int getnum_aux (lua_State *L, const char **pc) {
   int res = 0;
   int sig = 1;
   skip(pc);
   if (**pc == '.') {
-    res = (int)lua_tonumber(L, -1);
+    res = cast(int, lua_tonumber(L, -1));
     lua_pop(L, 1);
     (*pc)++;
     return res;
@@ -370,11 +561,11 @@ static int getnum (lua_State *L, const char **pc) {
     sig = -1;
     (*pc)++;
   }
-  while (isdigit(**pc)) res = res*10 + (*(*pc)++) - '0';
+  while (isdigit(cast(int, **pc))) res = res*10 + (*(*pc)++) - '0';
   return sig*res;
 }
   
-static const char *getname (char *buff, const char **pc) {
+static const char *getname_aux (char *buff, const char **pc) {
   int i = 0;
   skip(pc);
   while (**pc != '\0' && !strchr(delimits, **pc))
@@ -386,51 +577,52 @@ static const char *getname (char *buff, const char **pc) {
 
 #define EQ(s1)	(strcmp(s1, inst) == 0)
 
-#define getnum	((getnum)(L, &pc))
-#define getname	((getname)(buff, &pc))
+#define getnum	(getnum_aux(L, &pc))
+#define getname	(getname_aux(buff, &pc))
 
 
 static int testC (lua_State *L) {
   char buff[30];
-  const char *pc = luaL_check_string(L, 1);
+  const char *pc = luaL_checkstring(L, 1);
   for (;;) {
     const char *inst = getname;
     if EQ("") return 0;
     else if EQ("isnumber") {
-      lua_pushnumber(L, lua_isnumber(L, getnum));
+      lua_pushintegral(L, lua_isnumber(L, getnum));
     }
     else if EQ("isstring") {
-      lua_pushnumber(L, lua_isstring(L, getnum));
+      lua_pushintegral(L, lua_isstring(L, getnum));
     }
     else if EQ("istable") {
-      lua_pushnumber(L, lua_istable(L, getnum));
+      lua_pushintegral(L, lua_istable(L, getnum));
     }
     else if EQ("iscfunction") {
-      lua_pushnumber(L, lua_iscfunction(L, getnum));
+      lua_pushintegral(L, lua_iscfunction(L, getnum));
     }
     else if EQ("isfunction") {
-      lua_pushnumber(L, lua_isfunction(L, getnum));
+      lua_pushintegral(L, lua_isfunction(L, getnum));
     }
     else if EQ("isuserdata") {
-      lua_pushnumber(L, lua_isuserdata(L, getnum));
+      lua_pushintegral(L, lua_isuserdata(L, getnum));
+    }
+    else if EQ("isudataval") {
+      lua_pushintegral(L, lua_islightuserdata(L, getnum));
     }
     else if EQ("isnil") {
-      lua_pushnumber(L, lua_isnil(L, getnum));
+      lua_pushintegral(L, lua_isnil(L, getnum));
     }
     else if EQ("isnull") {
-      lua_pushnumber(L, lua_isnull(L, getnum));
+      lua_pushintegral(L, lua_isnone(L, getnum));
     }
     else if EQ("tonumber") {
       lua_pushnumber(L, lua_tonumber(L, getnum));
     }
     else if EQ("tostring") {
-      lua_pushstring(L, lua_tostring(L, getnum));
-    }
-    else if EQ("tonumber") {
-      lua_pushnumber(L, lua_tonumber(L, getnum));
+      const char *s = lua_tostring(L, getnum);
+      lua_pushstring(L, s);
     }
     else if EQ("strlen") {
-      lua_pushnumber(L, lua_strlen(L, getnum));
+      lua_pushintegral(L, lua_strlen(L, getnum));
     }
     else if EQ("tocfunction") {
       lua_pushcfunction(L, lua_tocfunction(L, getnum));
@@ -439,7 +631,7 @@ static int testC (lua_State *L) {
       return getnum;
     }
     else if EQ("gettop") {
-      lua_pushnumber(L, lua_gettop(L));
+      lua_pushintegral(L, lua_gettop(L));
     }
     else if EQ("settop") {
       lua_settop(L, getnum);
@@ -448,17 +640,35 @@ static int testC (lua_State *L) {
       lua_pop(L, getnum);
     }
     else if EQ("pushnum") {
-      lua_pushnumber(L, getnum);
+      lua_pushintegral(L, getnum);
+    }
+    else if EQ("pushnil") {
+      lua_pushnil(L);
+    }
+    else if EQ("pushbool") {
+      lua_pushboolean(L, getnum);
+    }
+    else if EQ("tobool") {
+      lua_pushintegral(L, lua_toboolean(L, getnum));
     }
     else if EQ("pushvalue") {
       lua_pushvalue(L, getnum);
     }
+    else if EQ("pushcclosure") {
+      lua_pushcclosure(L, testC, getnum);
+    }
+    else if EQ("pushupvalues") {
+      lua_pushupvalues(L);
+    }
     else if EQ("remove") {
       lua_remove(L, getnum);
     }
     else if EQ("insert") {
       lua_insert(L, getnum);
     }
+    else if EQ("replace") {
+      lua_replace(L, getnum);
+    }
     else if EQ("gettable") {
       lua_gettable(L, getnum);
     }
@@ -471,33 +681,53 @@ static int testC (lua_State *L) {
     else if EQ("concat") {
       lua_concat(L, getnum);
     }
+    else if EQ("lessthan") {
+      int a = getnum;
+      lua_pushboolean(L, lua_lessthan(L, a, getnum));
+    }
+    else if EQ("equal") {
+      int a = getnum;
+      lua_pushboolean(L, lua_equal(L, a, getnum));
+    }
     else if EQ("rawcall") {
       int narg = getnum;
       int nres = getnum;
-      lua_rawcall(L, narg, nres);
+      lua_call(L, narg, nres);
     }
     else if EQ("call") {
       int narg = getnum;
       int nres = getnum;
-      lua_call(L, narg, nres);
+      lua_pcall(L, narg, nres, 0);
+    }
+    else if EQ("loadstring") {
+      size_t sl;
+      const char *s = luaL_checklstring(L, getnum, &sl);
+      luaL_loadbuffer(L, s, sl, s);
     }
-    else if EQ("dostring") {
-      lua_dostring(L, luaL_check_string(L, getnum));
+    else if EQ("loadfile") {
+      luaL_loadfile(L, luaL_checkstring(L, getnum));
     }
-    else if EQ("settagmethod") {
-      int tag = getnum;
-      const char *event = getname;
-      lua_settagmethod(L, tag, event);
+    else if EQ("setmetatable") {
+      lua_setmetatable(L, getnum);
     }
-    else if EQ("gettagmethod") {
-      int tag = getnum;
-      const char *event = getname;
-      lua_gettagmethod(L, tag, event);
+    else if EQ("getmetatable") {
+      if (lua_getmetatable(L, getnum) == 0)
+        lua_pushnil(L);
     }
     else if EQ("type") {
       lua_pushstring(L, lua_typename(L, lua_type(L, getnum)));
     }
-    else luaL_verror(L, "unknown instruction %.30s", buff);
+    else if EQ("getn") {
+      int i = getnum;
+      lua_pushintegral(L, luaL_getn(L, i));
+    }
+    else if EQ("setn") {
+      int i = getnum;
+      int n = cast(int, lua_tonumber(L, -1));
+      luaL_setn(L, i, n);
+      lua_pop(L, 1);
+    }
+    else luaL_error(L, "unknown instruction %s", buff);
   }
   return 0;
 }
@@ -505,39 +735,118 @@ static int testC (lua_State *L) {
 /* }====================================================== */
 
 
+/*
+** {======================================================
+** tests for yield inside hooks
+** =======================================================
+*/
+
+static void yieldf (lua_State *L, lua_Debug *ar) {
+  lua_yield(L, 0);
+}
+
+static int setyhook (lua_State *L) {
+  if (lua_isnoneornil(L, 1))
+    lua_sethook(L, NULL, 0, 0);  /* turn off hooks */
+  else {
+    const char *smask = luaL_checkstring(L, 1);
+    int count = luaL_optint(L, 2, 0);
+    int mask = 0;
+    if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
+    if (count > 0) mask |= LUA_MASKCOUNT;
+    lua_sethook(L, yieldf, mask, count);
+  }
+  return 0;
+}
+
+
+static int coresume (lua_State *L) {
+  int status;
+  lua_State *co = lua_tothread(L, 1);
+  luaL_argcheck(L, co, 1, "coroutine expected");
+  status = lua_resume(co, 0);
+  if (status != 0) {
+    lua_pushboolean(L, 0);
+    lua_insert(L, -2);
+    return 2;  /* return false + error message */
+  }
+  else {
+    lua_pushboolean(L, 1);
+    return 1;
+  }
+}
+
+/* }====================================================== */
+
+
 
 static const struct luaL_reg tests_funcs[] = {
   {"hash", hash_query},
   {"limits", get_limits},
   {"listcode", listcode},
-  {"liststrings", liststrings},
+  {"listk", listk},
   {"listlocals", listlocals},
   {"loadlib", loadlib},
+  {"stacklevel", stacklevel},
   {"querystr", string_query},
   {"querytab", table_query},
+  {"doit", test_do},
   {"testC", testC},
   {"ref", tref},
   {"getref", getref},
   {"unref", unref},
+  {"d2s", d2s},
+  {"s2d", s2d},
+  {"metatable", metatable},
+  {"upvalue", upvalue},
   {"newuserdata", newuserdata},
+  {"pushuserdata", pushuserdata},
   {"udataval", udataval},
+  {"doonnewstack", doonnewstack},
   {"newstate", newstate},
   {"closestate", closestate},
   {"doremote", doremote},
-  {"settagmethod", settagmethod},
-  {"equal", equal},
-  {"totalmem", mem_query}
+  {"log2", log2_aux},
+  {"int2fb", int2fb_aux},
+  {"totalmem", mem_query},
+  {"resume", coresume},
+  {"setyhook", setyhook},
+  {NULL, NULL}
 };
 
 
-void luaB_opentests (lua_State *L) {
-  lua_newtable(L);
-  lua_getglobals(L);
-  lua_pushvalue(L, -2);
-  lua_setglobals(L);
-  luaL_openl(L, tests_funcs);  /* open functions inside new table */
-  lua_setglobals(L);  /* restore old table of globals */
-  lua_setglobal(L, "T");  /* set new table as global T */
+static void fim (void) {
+  if (!islocked)
+    lua_close(lua_state);
+  lua_assert(memdebug_numblocks == 0);
+  lua_assert(memdebug_total == 0);
+}
+
+
+static int l_panic (lua_State *L) {
+  UNUSED(L);
+  fprintf(stderr, "unable to recover; exiting\n");
+  return 0;
+}
+
+
+int luaB_opentests (lua_State *L) {
+  lua_atpanic(L, l_panic);
+  lua_userstateopen(L);  /* init lock */
+  lua_state = L;  /* keep first state to be opened */
+  luaL_openlib(L, "T", tests_funcs, 0);
+  atexit(fim);
+  return 0;
+}
+
+
+#undef main
+int main (int argc, char *argv[]) {
+  char *limit = getenv("MEMLIMIT");
+  if (limit)
+    memdebug_memlimit = strtoul(limit, NULL, 10);
+  l_main(argc, argv);
+  return 0;
 }
 
 #endif
diff --git a/src/ltm.c b/src/ltm.c
index a20909a1..1b3e515e 100644
--- a/src/ltm.c
+++ b/src/ltm.c
@@ -1,163 +1,70 @@
 /*
-** $Id: ltm.c,v 1.56 2000/10/31 13:10:24 roberto Exp $
+** $Id: ltm.c,v 1.106 2003/04/03 13:35:34 roberto Exp $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
 
 
-#include <stdio.h>
 #include <string.h>
 
+#define ltm_c
+
 #include "lua.h"
 
-#include "ldo.h"
-#include "lmem.h"
 #include "lobject.h"
 #include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
 #include "ltm.h"
 
 
-const char *const luaT_eventname[] = {  /* ORDER TM */
-  "gettable", "settable", "index", "getglobal", "setglobal", "add", "sub",
-  "mul", "div", "pow", "unm", "lt", "concat", "gc", "function",
-  "le", "gt", "ge",  /* deprecated options!! */
-  NULL
-};
-
-
-static int findevent (const char *name) {
-  int i;
-  for (i=0; luaT_eventname[i]; i++)
-    if (strcmp(luaT_eventname[i], name) == 0)
-      return i;
-  return -1;  /* name not found */
-}
-
-
-static int luaI_checkevent (lua_State *L, const char *name, int t) {
-  int e = findevent(name);
-  if (e >= TM_N)
-    luaO_verror(L, "event `%.50s' is deprecated", name);
-  if (e == TM_GC && t == LUA_TTABLE)
-    luaO_verror(L, "event `gc' for tables is deprecated");
-  if (e < 0)
-    luaO_verror(L, "`%.50s' is not a valid event name", name);
-  return e;
-}
-
-
 
-/* events in LUA_TNIL are all allowed, since this is used as a
-*  'placeholder' for "default" fallbacks
-*/
-/* ORDER LUA_T, ORDER TM */
-static const char luaT_validevents[NUM_TAGS][TM_N] = {
-  {1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},  /* LUA_TUSERDATA */
-  {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},  /* LUA_TNIL */
-  {1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1},  /* LUA_TNUMBER */
-  {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},  /* LUA_TSTRING */
-  {0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1},  /* LUA_TTABLE */
-  {1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}   /* LUA_TFUNCTION */
+const char *const luaT_typenames[] = {
+  "nil", "boolean", "userdata", "number",
+  "string", "table", "function", "userdata", "thread"
 };
 
-int luaT_validevent (int t, int e) {  /* ORDER LUA_T */
-  return (t >= NUM_TAGS) ?  1 : luaT_validevents[t][e];
-}
-
-
-static void init_entry (lua_State *L, int tag) {
-  int i;
-  for (i=0; i<TM_N; i++)
-    luaT_gettm(L, tag, i) = NULL;
-  L->TMtable[tag].collected = NULL;
-}
-
 
 void luaT_init (lua_State *L) {
-  int t;
-  luaM_growvector(L, L->TMtable, 0, NUM_TAGS, struct TM, "", MAX_INT);
-  L->nblocks += NUM_TAGS*sizeof(struct TM);
-  L->last_tag = NUM_TAGS-1;
-  for (t=0; t<=L->last_tag; t++)
-    init_entry(L, t);
-}
-
-
-LUA_API int lua_newtag (lua_State *L) {
-  luaM_growvector(L, L->TMtable, L->last_tag, 1, struct TM,
-                  "tag table overflow", MAX_INT);
-  L->nblocks += sizeof(struct TM);
-  L->last_tag++;
-  init_entry(L, L->last_tag);
-  return L->last_tag;
-}
-
-
-static void checktag (lua_State *L, int tag) {
-  if (!(0 <= tag && tag <= L->last_tag))
-    luaO_verror(L, "%d is not a valid tag", tag);
-}
-
-void luaT_realtag (lua_State *L, int tag) {
-  if (!validtag(tag))
-    luaO_verror(L, "tag %d was not created by `newtag'", tag);
-}
-
-
-LUA_API int lua_copytagmethods (lua_State *L, int tagto, int tagfrom) {
-  int e;
-  checktag(L, tagto);
-  checktag(L, tagfrom);
-  for (e=0; e<TM_N; e++) {
-    if (luaT_validevent(tagto, e))
-      luaT_gettm(L, tagto, e) = luaT_gettm(L, tagfrom, e);
-  }
-  return tagto;
-}
-
-
-int luaT_tag (const TObject *o) {
-  int t = ttype(o);
-  switch (t) {
-    case LUA_TUSERDATA: return tsvalue(o)->u.d.tag;
-    case LUA_TTABLE:    return hvalue(o)->htag;
-    default:            return t;
+  static const char *const luaT_eventname[] = {  /* ORDER TM */
+    "__index", "__newindex",
+    "__gc", "__mode", "__eq",
+    "__add", "__sub", "__mul", "__div",
+    "__pow", "__unm", "__lt", "__le",
+    "__concat", "__call"
+  };
+  int i;
+  for (i=0; i<TM_N; i++) {
+    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
+    luaS_fix(G(L)->tmname[i]);  /* never collect these names */
   }
 }
 
 
-LUA_API void lua_gettagmethod (lua_State *L, int t, const char *event) {
-  int e;
-  e = luaI_checkevent(L, event, t);
-  checktag(L, t);
-  if (luaT_validevent(t, e) && luaT_gettm(L, t, e)) {
-    clvalue(L->top) = luaT_gettm(L, t, e);
-    ttype(L->top) = LUA_TFUNCTION;
+/*
+** function to be used with macro "fasttm": optimized for absence of
+** tag methods
+*/
+const TObject *luaT_gettm (Table *events, TMS event, TString *ename) {
+  const TObject *tm = luaH_getstr(events, ename);
+  lua_assert(event <= TM_EQ);
+  if (ttisnil(tm)) {  /* no tag method? */
+    events->flags |= cast(lu_byte, 1u<<event);  /* cache this fact */
+    return NULL;
   }
-  else
-    ttype(L->top) = LUA_TNIL;
-  incr_top;
+  else return tm;
 }
 
 
-LUA_API void lua_settagmethod (lua_State *L, int t, const char *event) {
-  int e = luaI_checkevent(L, event, t);
-  checktag(L, t);
-  if (!luaT_validevent(t, e))
-    luaO_verror(L, "cannot change `%.20s' tag method for type `%.20s'%.20s",
-                luaT_eventname[e], luaO_typenames[t],
-                (t == LUA_TTABLE || t == LUA_TUSERDATA) ?
-                   " with default tag" : "");
-  switch (ttype(L->top - 1)) {
-    case LUA_TNIL:
-      luaT_gettm(L, t, e) = NULL;
-      break;
-    case LUA_TFUNCTION:
-      luaT_gettm(L, t, e) = clvalue(L->top - 1);
-      break;
+const TObject *luaT_gettmbyobj (lua_State *L, const TObject *o, TMS event) {
+  TString *ename = G(L)->tmname[event];
+  switch (ttype(o)) {
+    case LUA_TTABLE:
+      return luaH_getstr(hvalue(o)->metatable, ename);
+    case LUA_TUSERDATA:
+      return luaH_getstr(uvalue(o)->uv.metatable, ename);
     default:
-      lua_error(L, "tag method must be a function (or nil)");
+      return &luaO_nilobject;
   }
-  L->top--;
 }
 
diff --git a/src/ltm.h b/src/ltm.h
index 3bd8e827..8eebfd3d 100644
--- a/src/ltm.h
+++ b/src/ltm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.h,v 1.18 2000/10/05 13:00:17 roberto Exp $
+** $Id: ltm.h,v 1.41 2002/11/14 11:51:50 roberto Exp $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -9,18 +9,18 @@
 
 
 #include "lobject.h"
-#include "lstate.h"
+
 
 /*
 * WARNING: if you change the order of this enumeration,
 * grep "ORDER TM"
 */
 typedef enum {
-  TM_GETTABLE = 0,
-  TM_SETTABLE,
   TM_INDEX,
-  TM_GETGLOBAL,
-  TM_SETGLOBAL,
+  TM_NEWINDEX,
+  TM_GC,
+  TM_MODE,
+  TM_EQ,  /* last tag method with `fast' access */
   TM_ADD,
   TM_SUB,
   TM_MUL,
@@ -28,32 +28,24 @@ typedef enum {
   TM_POW,
   TM_UNM,
   TM_LT,
+  TM_LE,
   TM_CONCAT,
-  TM_GC,
-  TM_FUNCTION,
+  TM_CALL,
   TM_N		/* number of elements in the enum */
 } TMS;
 
 
-struct TM {
-  Closure *method[TM_N];
-  TString *collected;  /* list of garbage-collected udata with this tag */
-};
-
-
-#define luaT_gettm(L,tag,event) (L->TMtable[tag].method[event])
-#define luaT_gettmbyObj(L,o,e)  (luaT_gettm((L),luaT_tag(o),(e)))
-
 
-#define validtag(t) (NUM_TAGS <= (t) && (t) <= L->last_tag)
+#define gfasttm(g,et,e) \
+  (((et)->flags & (1u<<(e))) ? NULL : luaT_gettm(et, e, (g)->tmname[e]))
 
-extern const char *const luaT_eventname[];
+#define fasttm(l,et,e)	gfasttm(G(l), et, e)
 
 
+const TObject *luaT_gettm (Table *events, TMS event, TString *ename);
+const TObject *luaT_gettmbyobj (lua_State *L, const TObject *o, TMS event);
 void luaT_init (lua_State *L);
-void luaT_realtag (lua_State *L, int tag);
-int luaT_tag (const TObject *o);
-int luaT_validevent (int t, int e);  /* used by compatibility module */
 
+extern const char *const luaT_typenames[];
 
 #endif
diff --git a/src/lua/Makefile b/src/lua/Makefile
index 5b47161f..aa52832f 100644
--- a/src/lua/Makefile
+++ b/src/lua/Makefile
@@ -4,17 +4,16 @@ LUA= ../..
 
 include $(LUA)/config
 
-EXTRA_DEFS= $(POSIX)
-
+EXTRA_DEFS= $(USERCONF)
 OBJS= lua.o
 SRCS= lua.c
 
 T= $(BIN)/lua
 
-all: $T
+all:	$T
 
-$T: $(OBJS) $(LIB)/liblua.a $(LIB)/liblualib.a
-	$(CC) -o $@ $(OBJS) -L$(LIB) -llua -llualib $(EXTRA_LIBS)
+$T:	$(OBJS) $(LIB)/liblua.a $(LIB)/liblualib.a
+	$(CC) -o $@ $(MYLDFLAGS) $(OBJS) -L$(LIB) -llua -llualib $(EXTRA_LIBS) $(DLLIB)
 
 $(LIB)/liblua.a:
 	cd ..; $(MAKE)
diff --git a/src/lua/README b/src/lua/README
index 832fb5bf..febd229a 100644
--- a/src/lua/README
+++ b/src/lua/README
@@ -2,39 +2,31 @@ This is lua, a sample Lua interpreter.
 It can be used as a batch interpreter and also interactively.
 There are man pages for it in both nroff and html in ../../doc.
 
-Here are the options that it understands:
+Usage: ./lua [options] [script [args]].  Available options are:
   -        execute stdin as a file
-  -c       close Lua when exiting
   -e stat  execute string `stat'
-  -f name  execute file `name' with remaining arguments in table `arg'
-  -i       enter interactive mode with prompt
-  -q       enter interactive mode without prompt
-  -sNUM    set stack size to NUM (must be the first option)
-  -v       print version information
-  a=b      set global `a' to string `b'
-  name     execute file `name'
+  -i       enter interactive mode after executing `script'
+  -l name  load and run library `name'
+  -v       show version information
+  --       stop handling options
 
-If no options are given, then it reads lines from stdin and executes them
-as they are read -- so, each line must contain a complete statement.
-To span a statement across several lines, end each line with a backslash '\'.
+This interpreter is suitable for using Lua as a standalone language; it loads
+all standard libraries. For a minimal interpreter, see ../../etc/min.c.
 
-To change the prompt, set the global variable _PROMPT to whatever you want.
-You can do this after calling the interpreter or on the command line with
-	lua _PROMPT="lua: " -i
-for example. Note that you need "-i" in this case.
+If your application simply exports new functions to Lua (which is common),
+then you can use this interpreter (almost) unmodified, as follows:
 
-You must be careful when using quotes on the command line because they are
-usually handled by the shell.
+* First, define a function 
+	 void myinit (lua_State *L)
+  in your own code. In this function, you should do whatever initializations
+  are needed by your application, typically exporting your functions to Lua.
+  (Of course, you can use any name instead of "myinit".)
 
-This interpreter is good for using Lua as a standalone language.
-For a minimal interpreter, see ../../etc/min.c.
+* Then, #define lua_userinit(L) to be "openstdlibs(L)+myinit(L)".
+  Here, openstdlibs is a function in lua.c that opens all standard libraries.
+  If you don't need them, just don't call openstdlibs and open any standard
+  libraries that you do need in myinit.
 
-If your application simply exports new functions to Lua (which is common),
-then you can use this interpreter (almost) unmodified, as follows:
-First, define a function 
-	void myinit (lua_State *L)
-in your own code. In this function, you should do whatever initializations
-are needed by your application, typically exporting your functions to Lua.
-Then, add a call "myinit(L)" in lua.c after the place marked
-	"add your libraries here"
-Of course, you can use any name instead of "myinit".
+* Finally, remember to link your C code when building lua.
+
+For other customizations, see ../../etc/config.c.
diff --git a/src/lua/lua.c b/src/lua/lua.c
index 2da857e1..28c84cb6 100644
--- a/src/lua/lua.c
+++ b/src/lua/lua.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.c,v 1.55 2000/10/20 16:36:32 roberto Exp $
+** $Id: lua.c,v 1.122 2003/04/03 13:34:42 roberto Exp $
 ** Lua stand-alone interpreter
 ** See Copyright Notice in lua.h
 */
@@ -10,313 +10,429 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define lua_c
+
 #include "lua.h"
 
-#include "luadebug.h"
+#include "lauxlib.h"
 #include "lualib.h"
 
 
-static lua_State *L = NULL;
+/*
+** generic extra include file
+*/
+#ifdef LUA_USERCONFIG
+#include LUA_USERCONFIG
+#endif
+
+
+/*
+** definition of `isatty'
+*/
+#ifdef _POSIX_C_SOURCE
+#include <unistd.h>
+#define stdin_is_tty()	isatty(0)
+#else
+#define stdin_is_tty()	1  /* assume stdin is a tty */
+#endif
+
 
 
 #ifndef PROMPT
 #define PROMPT		"> "
 #endif
 
-#ifdef _POSIX_SOURCE
-#include <unistd.h>
-#else
-static int isatty (int x) { return x==0; }  /* assume stdin is a tty */
+
+#ifndef PROMPT2
+#define PROMPT2		">> "
 #endif
 
+#ifndef PROGNAME
+#define PROGNAME	"lua"
+#endif
 
-/*
-** global options
-*/
-struct Options {
-  int toclose;
-  int stacksize;
-};
+#ifndef lua_userinit
+#define lua_userinit(L)		openstdlibs(L)
+#endif
 
 
-typedef void (*handler)(int);  /* type for signal actions */
+#ifndef LUA_EXTRALIBS
+#define LUA_EXTRALIBS	/* empty */
+#endif
 
-static void laction (int i);
 
+static lua_State *L = NULL;
 
-static lua_Hook old_linehook = NULL;
-static lua_Hook old_callhook = NULL;
+static const char *progname = PROGNAME;
 
 
-static void userinit (void) {
-  lua_baselibopen(L);
-  lua_iolibopen(L);
-  lua_strlibopen(L);
-  lua_mathlibopen(L);
-  lua_dblibopen(L);
+
+static const luaL_reg lualibs[] = {
+  {"base", luaopen_base},
+  {"table", luaopen_table},
+  {"io", luaopen_io},
+  {"string", luaopen_string},
+  {"math", luaopen_math},
+  {"debug", luaopen_debug},
+  {"loadlib", luaopen_loadlib},
   /* add your libraries here */
-}
+  LUA_EXTRALIBS
+  {NULL, NULL}
+};
 
 
-static handler lreset (void) {
-  return signal(SIGINT, laction);
-}
 
-
-static void lstop (void) {
-  lua_setlinehook(L, old_linehook);
-  lua_setcallhook(L, old_callhook);
-  lreset();
-  lua_error(L, "interrupted!");
+static void lstop (lua_State *l, lua_Debug *ar) {
+  (void)ar;  /* unused arg. */
+  lua_sethook(l, NULL, 0, 0);
+  luaL_error(l, "interrupted!");
 }
 
 
 static void laction (int i) {
-  (void)i;  /* to avoid warnings */
-  signal(SIGINT, SIG_DFL); /* if another SIGINT happens before lstop,
+  signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
                               terminate process (default action) */
-  old_linehook = lua_setlinehook(L, (lua_Hook)lstop);
-  old_callhook = lua_setcallhook(L, (lua_Hook)lstop);
-}
-
-
-static int ldo (int (*f)(lua_State *l, const char *), const char *name) {
-  int res;
-  handler h = lreset();
-  int top = lua_gettop(L);
-  res = f(L, name);  /* dostring | dofile */
-  lua_settop(L, top);  /* remove eventual results */
-  signal(SIGINT, h);  /* restore old action */
-  /* Lua gives no message in such cases, so lua.c provides one */
-  if (res == LUA_ERRMEM) {
-    fprintf(stderr, "lua: memory allocation error\n");
-  }
-  else if (res == LUA_ERRERR)
-    fprintf(stderr, "lua: error in error message\n");
-  return res;
+  lua_sethook(L, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
 }
 
 
-static void print_message (void) {
+static void print_usage (void) {
   fprintf(stderr,
-  "usage: lua [options].  Available options are:\n"
+  "usage: %s [options] [script [args]].\n"
+  "Available options are:\n"
   "  -        execute stdin as a file\n"
-  "  -c       close Lua when exiting\n"
   "  -e stat  execute string `stat'\n"
-  "  -f name  execute file `name' with remaining arguments in table `arg'\n"
-  "  -i       enter interactive mode with prompt\n"
-  "  -q       enter interactive mode without prompt\n"
-  "  -sNUM    set stack size to NUM (must be the first option)\n"
-  "  -v       print version information\n"
-  "  a=b      set global `a' to string `b'\n"
-  "  name     execute file `name'\n"
-);
+  "  -i       enter interactive mode after executing `script'\n"
+  "  -l name  load and run library `name'\n"
+  "  -v       show version information\n"
+  "  --       stop handling options\n" ,
+  progname);
 }
 
 
-static void print_version (void) {
-  printf("%.80s  %.80s\n", LUA_VERSION, LUA_COPYRIGHT);
+static void l_message (const char *pname, const char *msg) {
+  if (pname) fprintf(stderr, "%s: ", pname);
+  fprintf(stderr, "%s\n", msg);
 }
 
 
-static void assign (char *arg) {
-  char *eq = strchr(arg, '=');
-  *eq = '\0';  /* spilt `arg' in two strings (name & value) */
-  lua_pushstring(L, eq+1);
-  lua_setglobal(L, arg);
+static int report (int status) {
+  const char *msg;
+  if (status) {
+    msg = lua_tostring(L, -1);
+    if (msg == NULL) msg = "(error with no message)";
+    l_message(progname, msg);
+    lua_pop(L, 1);
+  }
+  return status;
 }
 
 
-static void getargs (char *argv[]) {
+static int lcall (int narg, int clear) {
+  int status;
+  int base = lua_gettop(L) - narg;  /* function index */
+  lua_pushliteral(L, "_TRACEBACK");
+  lua_rawget(L, LUA_GLOBALSINDEX);  /* get traceback function */
+  lua_insert(L, base);  /* put it under chunk and args */
+  signal(SIGINT, laction);
+  status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
+  signal(SIGINT, SIG_DFL);
+  lua_remove(L, base);  /* remove traceback function */
+  return status;
+}
+
+
+static void print_version (void) {
+  l_message(NULL, LUA_VERSION "  " LUA_COPYRIGHT);
+}
+
+
+static void getargs (char *argv[], int n) {
   int i;
   lua_newtable(L);
   for (i=0; argv[i]; i++) {
-    /* arg[i] = argv[i] */
-    lua_pushnumber(L, i);
+    lua_pushnumber(L, i - n);
     lua_pushstring(L, argv[i]);
-    lua_settable(L, -3);
+    lua_rawset(L, -3);
   }
   /* arg.n = maximum index in table `arg' */
-  lua_pushstring(L, "n");
-  lua_pushnumber(L, i-1);
-  lua_settable(L, -3);
+  lua_pushliteral(L, "n");
+  lua_pushnumber(L, i-n-1);
+  lua_rawset(L, -3);
 }
 
 
-static int l_getargs (lua_State *l) {
-  char **argv = (char **)lua_touserdata(l, -1);
-  getargs(argv);
-  return 1;
+static int docall (int status) {
+  if (status == 0) status = lcall(0, 1);
+  return report(status);
 }
 
 
-static int file_input (const char *argv) {
-  int result = ldo(lua_dofile, argv);
-  if (result) {
-    if (result == LUA_ERRFILE) {
-      fprintf(stderr, "lua: cannot execute file ");
-      perror(argv);
-    }
-    return EXIT_FAILURE;
+static int file_input (const char *name) {
+  return docall(luaL_loadfile(L, name));
+}
+
+
+static int dostring (const char *s, const char *name) {
+  return docall(luaL_loadbuffer(L, s, strlen(s), name));
+}
+
+
+static int load_file (const char *name) {
+  lua_pushliteral(L, "require");
+  lua_rawget(L, LUA_GLOBALSINDEX);
+  if (!lua_isfunction(L, -1)) {  /* no `require' defined? */
+    lua_pop(L, 1);
+    return file_input(name);
+  }
+  else {
+    lua_pushstring(L, name);
+    return report(lcall(1, 1));
   }
-  else
-    return EXIT_SUCCESS;
 }
 
 
-/* maximum length of an input string */
+/*
+** this macro can be used by some `history' system to save lines
+** read in manual input
+*/
+#ifndef lua_saveline
+#define lua_saveline(L,line)	/* empty */
+#endif
+
+
+/*
+** this macro defines a function to show the prompt and reads the
+** next line for manual input
+*/
+#ifndef lua_readline
+#define lua_readline(L,prompt)		readline(L,prompt)
+
+/* maximum length of an input line */
 #ifndef MAXINPUT
-#define MAXINPUT	BUFSIZ
+#define MAXINPUT	512
 #endif
 
-static void manual_input (int version, int prompt) {
-  int cont = 1;
-  if (version) print_version();
-  while (cont) {
-    char buffer[MAXINPUT];
-    int i = 0;
-    if (prompt) {
-      const char *s;
-      lua_getglobal(L, "_PROMPT");
-      s = lua_tostring(L, -1);
-      if (!s) s = PROMPT;
-      fputs(s, stdout);
-      lua_pop(L, 1);  /* remove global */
-    }
-    for(;;) {
-      int c = getchar();
-      if (c == EOF) {
-        cont = 0;
-        break;
-      }
-      else if (c == '\n') {
-        if (i>0 && buffer[i-1] == '\\')
-          buffer[i-1] = '\n';
-        else break;
-      }
-      else if (i >= MAXINPUT-1) {
-        fprintf(stderr, "lua: input line too long\n");
-        break;
-      }
-      else buffer[i++] = (char)c;
+
+static int readline (lua_State *l, const char *prompt) {
+  static char buffer[MAXINPUT];
+  if (prompt) {
+    fputs(prompt, stdout);
+    fflush(stdout);
+  }
+  if (fgets(buffer, sizeof(buffer), stdin) == NULL)
+    return 0;  /* read fails */
+  else {
+    lua_pushstring(l, buffer);
+    return 1;
+  }
+}
+
+#endif
+
+
+static const char *get_prompt (int firstline) {
+  const char *p = NULL;
+  lua_pushstring(L, firstline ? "_PROMPT" : "_PROMPT2");
+  lua_rawget(L, LUA_GLOBALSINDEX);
+  p = lua_tostring(L, -1);
+  if (p == NULL) p = (firstline ? PROMPT : PROMPT2);
+  lua_pop(L, 1);  /* remove global */
+  return p;
+}
+
+
+static int incomplete (int status) {
+  if (status == LUA_ERRSYNTAX &&
+         strstr(lua_tostring(L, -1), "near `<eof>'") != NULL) {
+    lua_pop(L, 1);
+    return 1;
+  }
+  else
+    return 0;
+}
+
+
+static int load_string (void) {
+  int status;
+  lua_settop(L, 0);
+  if (lua_readline(L, get_prompt(1)) == 0)  /* no input? */
+    return -1;
+  if (lua_tostring(L, -1)[0] == '=') {  /* line starts with `=' ? */
+    lua_pushfstring(L, "return %s", lua_tostring(L, -1)+1);/* `=' -> `return' */
+    lua_remove(L, -2);  /* remove original line */
+  }
+  for (;;) {  /* repeat until gets a complete line */
+    status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");
+    if (!incomplete(status)) break;  /* cannot try to add lines? */
+    if (lua_readline(L, get_prompt(0)) == 0)  /* no more input? */
+      return -1;
+    lua_concat(L, lua_gettop(L));  /* join lines */
+  }
+  lua_saveline(L, lua_tostring(L, 1));
+  lua_remove(L, 1);  /* remove line */
+  return status;
+}
+
+
+static void manual_input (void) {
+  int status;
+  const char *oldprogname = progname;
+  progname = NULL;
+  while ((status = load_string()) != -1) {
+    if (status == 0) status = lcall(0, 0);
+    report(status);
+    if (status == 0 && lua_gettop(L) > 0) {  /* any result to print? */
+      lua_getglobal(L, "print");
+      lua_insert(L, 1);
+      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
+        l_message(progname, lua_pushfstring(L, "error calling `print' (%s)",
+                                               lua_tostring(L, -1)));
     }
-    buffer[i] = '\0';
-    ldo(lua_dostring, buffer);
-    lua_settop(L, 0);  /* remove eventual results */
   }
-  printf("\n");
+  lua_settop(L, 0);  /* clear stack */
+  fputs("\n", stdout);
+  progname = oldprogname;
 }
 
 
-static int handle_argv (char *argv[], struct Options *opt) {
-  if (opt->stacksize > 0) argv++;  /* skip option `-s' (if present) */
-  if (*argv == NULL) {  /* no more arguments? */
-    if (isatty(0)) {
-      manual_input(1, 1);
+static int handle_argv (char *argv[], int *interactive) {
+  if (argv[1] == NULL) {  /* no more arguments? */
+    if (stdin_is_tty()) {
+      print_version();
+      manual_input();
     }
     else
-      ldo(lua_dofile, NULL);  /* executes stdin as a file */
+      file_input(NULL);  /* executes stdin as a file */
   }
   else {  /* other arguments; loop over them */
     int i;
-    for (i = 0; argv[i] != NULL; i++) {
-      if (argv[i][0] != '-') {  /* not an option? */
-        if (strchr(argv[i], '='))
-          assign(argv[i]);
-        else
-          if (file_input(argv[i]) != EXIT_SUCCESS)
-            return EXIT_FAILURE;  /* stop if file fails */
-        }
-        else switch (argv[i][1]) {  /* option */
-          case 0: {
-            ldo(lua_dofile, NULL);  /* executes stdin as a file */
-            break;
-          }
-          case 'i': {
-            manual_input(0, 1);
-            break;
-          }
-          case 'q': {
-            manual_input(0, 0);
-            break;
-          }
-          case 'c': {
-            opt->toclose = 1;
-            break;
+    for (i = 1; argv[i] != NULL; i++) {
+      if (argv[i][0] != '-') break;  /* not an option? */
+      switch (argv[i][1]) {  /* option */
+        case '-': {  /* `--' */
+          if (argv[i][2] != '\0') {
+            print_usage();
+            return 1;
           }
-          case 'v': {
-            print_version();
-            break;
-          }
-          case 'e': {
-            i++;
-            if (argv[i] == NULL) {
-              print_message();
-              return EXIT_FAILURE;
-            }
-            if (ldo(lua_dostring, argv[i]) != 0) {
-              fprintf(stderr, "lua: error running argument `%.99s'\n", argv[i]);
-              return EXIT_FAILURE;
-            }
-            break;
-          }
-          case 'f': {
-            i++;
-            if (argv[i] == NULL) {
-              print_message();
-              return EXIT_FAILURE;
-            }
-            getargs(argv+i);  /* collect remaining arguments */
-            lua_setglobal(L, "arg");
-            return file_input(argv[i]);  /* stop scanning arguments */
-          }
-          case 's': {
-            fprintf(stderr, "lua: stack size (`-s') must be the first option\n");
-            return EXIT_FAILURE;
+          i++;  /* skip this argument */
+          goto endloop;  /* stop handling arguments */
+        }
+        case '\0': {
+          file_input(NULL);  /* executes stdin as a file */
+          break;
+        }
+        case 'i': {
+          *interactive = 1;
+          break;
+        }
+        case 'v': {
+          print_version();
+          break;
+        }
+        case 'e': {
+          const char *chunk = argv[i] + 2;
+          if (*chunk == '\0') chunk = argv[++i];
+          if (chunk == NULL) {
+            print_usage();
+            return 1;
           }
-          default: {
-            print_message();
-            return EXIT_FAILURE;
+          if (dostring(chunk, "=<command line>") != 0)
+            return 1;
+          break;
+        }
+        case 'l': {
+          const char *filename = argv[i] + 2;
+          if (*filename == '\0') filename = argv[++i];
+          if (filename == NULL) {
+            print_usage();
+            return 1;
           }
+          if (load_file(filename))
+            return 1;  /* stop if file fails */
+          break;
+        }
+        case 'c': {
+          l_message(progname, "option `-c' is deprecated");
+          break;
+        }
+        case 's': {
+          l_message(progname, "option `-s' is deprecated");
+          break;
+        }
+        default: {
+          print_usage();
+          return 1;
         }
+      }
+    } endloop:
+    if (argv[i] != NULL) {
+      const char *filename = argv[i];
+      getargs(argv, i);  /* collect arguments */
+      lua_setglobal(L, "arg");
+      return file_input(filename);  /* stop scanning arguments */
     }
   }
-  return EXIT_SUCCESS;
+  return 0;
 }
 
 
-static void getstacksize (int argc, char *argv[], struct Options *opt) {
-  if (argc >= 2 && argv[1][0] == '-' && argv[1][1] == 's') {
-    int stacksize = atoi(&argv[1][2]);
-    if (stacksize <= 0) {
-      fprintf(stderr, "lua: invalid stack size ('%.20s')\n", &argv[1][2]);
-      exit(EXIT_FAILURE);
-    }
-    opt->stacksize = stacksize;
+static void openstdlibs (lua_State *l) {
+  const luaL_reg *lib = lualibs;
+  for (; lib->func; lib++) {
+    lib->func(l);  /* open library */
+    lua_settop(l, 0);  /* discard any results */
   }
+}
+
+
+static int handle_luainit (void) {
+  const char *init = getenv("LUA_INIT");
+  if (init == NULL) return 0;  /* status OK */
+  else if (init[0] == '@')
+    return file_input(init+1);
   else
-    opt->stacksize = 0;  /* no stack size */
+    return dostring(init, "=LUA_INIT");
 }
 
 
-static void register_getargs (char *argv[]) {
-  lua_pushuserdata(L, argv);
-  lua_pushcclosure(L, l_getargs, 1);
-  lua_setglobal(L, "getargs");
+struct Smain {
+  int argc;
+  char **argv;
+  int status;
+};
+
+
+static int pmain (lua_State *l) {
+  struct Smain *s = (struct Smain *)lua_touserdata(l, 1);
+  int status;
+  int interactive = 0;
+  if (s->argv[0] && s->argv[0][0]) progname = s->argv[0];
+  L = l;
+  lua_userinit(l);  /* open libraries */
+  status = handle_luainit();
+  if (status == 0) {
+    status = handle_argv(s->argv, &interactive);
+    if (status == 0 && interactive) manual_input();
+  }
+  s->status = status;
+  return 0;
 }
 
 
 int main (int argc, char *argv[]) {
-  struct Options opt;
   int status;
-  opt.toclose = 0;
-  getstacksize(argc, argv, &opt);  /* handle option `-s' */
-  L = lua_open(opt.stacksize);  /* create state */
-  userinit();  /* open libraries */
-  register_getargs(argv);  /* create `getargs' function */
-  status = handle_argv(argv+1, &opt);
-  if (opt.toclose)
-    lua_close(L);
-  return status;
+  struct Smain s;
+  lua_State *l = lua_open();  /* create state */
+  if (l == NULL) {
+    l_message(argv[0], "cannot create state: not enough memory");
+    return EXIT_FAILURE;
+  }
+  s.argc = argc;
+  s.argv = argv;
+  status = lua_cpcall(l, &pmain, &s);
+  report(status);
+  lua_close(l);
+  return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
 }
 
diff --git a/src/luac/Makefile b/src/luac/Makefile
index 4517d82b..7a620826 100644
--- a/src/luac/Makefile
+++ b/src/luac/Makefile
@@ -4,20 +4,27 @@ LUA= ../..
 
 include $(LUA)/config
 
-INCS= -I$(INC) $(EXTRA_INCS) -I..
-OBJS= dump.o luac.o opt.o print.o stubs.o
-SRCS= dump.c luac.c opt.c print.c stubs.c luac.h print.h
+INCS= -I$(INC) -I.. $(EXTRA_INCS)
+OBJS= luac.o print.o lopcodes.o
+SRCS= luac.c print.c
 
 T= $(BIN)/luac
 
-all: $T
+all:	$T
 
-$T: $(OBJS) $(LIB)/liblua.a
-	$(CC) -o $@ $(OBJS) -L$(LIB) -llua
+$T:	$(OBJS) $(LIB)/liblua.a $(LIB)/liblualib.a
+	$(CC) -o $@ $(MYLDFLAGS) $(OBJS) -L$(LIB) -llua -llualib $(EXTRA_LIBS)
+
+# print.c needs opcode names from lopcodes.c
+lopcodes.o:	../lopcodes.c ../lopcodes.h
+	$(CC) -o $@ -c $(CFLAGS) -DLUA_OPNAMES ../lopcodes.c
 
 $(LIB)/liblua.a:
 	cd ..; $(MAKE)
 
+$(LIB)/liblualib.a:
+	cd ../lib; $(MAKE)
+
 clean:
 	rm -f $(OBJS) $T
 
diff --git a/src/luac/README b/src/luac/README
index 8d8bb491..ada7bc4b 100644
--- a/src/luac/README
+++ b/src/luac/README
@@ -1,22 +1,18 @@
 This is luac, the Lua compiler.
 There are man pages for it in both nroff and html in ../../doc.
 
-luac translates Lua programs into binary files that can be loaded and executed
-with lua_dofile in C or with dofile in Lua.
+luac translates Lua programs into binary files that can be loaded latter.
 The main advantages of pre-compiling chunks are: faster loading, protecting
 source code from user changes, and off-line syntax error detection.
 luac can also be used to learn about the Lua virtual machine.
 
-Here are the options that luac understands:
-
+Usage: /l/luac/luac [options] [filenames].  Available options are:
   -        process stdin
   -l       list
-  -o file  output file (default is "luac.out")
+  -o name  output to file `name' (default is "luac.out")
   -p       parse only
   -s       strip debug information
-  -t       test code integrity
   -v       show version information
+  --       stop handling options
 
 luac is also an example of how to use the internals of Lua (politely).
-Finally, luac does not need the runtime code, and stubs.c makes sure it is not
-linked into luac. This file also shows how to avoid linking the parser.
diff --git a/src/luac/dump.c b/src/luac/dump.c
deleted file mode 100644
index 149469ba..00000000
--- a/src/luac/dump.c
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
-** $Id: dump.c,v 1.30 2000/10/31 16:57:23 lhf Exp $
-** save bytecodes to file
-** See Copyright Notice in lua.h
-*/
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "luac.h"
-
-#define DumpVector(b,n,size,D)	fwrite(b,size,n,D)
-#define DumpBlock(b,size,D)	fwrite(b,size,1,D)
-#define	DumpByte		fputc
-
-static void DumpInt(int x, FILE* D)
-{
- DumpBlock(&x,sizeof(x),D);
-}
-
-static void DumpSize(size_t x, FILE* D)
-{
- DumpBlock(&x,sizeof(x),D);
-}
-
-static void DumpNumber(Number x, FILE* D)
-{
- DumpBlock(&x,sizeof(x),D);
-}
-
-static void DumpString(const TString* s, FILE* D)
-{
- if (s==NULL || s->str==NULL)
-  DumpSize(0,D);
- else
- {
-  size_t size=s->len+1;			/* include trailing '\0' */
-  DumpSize(size,D);
-  DumpBlock(s->str,size,D);
- }
-}
-
-static void DumpCode(const Proto* tf, FILE* D)
-{
- DumpInt(tf->ncode,D);
- DumpVector(tf->code,tf->ncode,sizeof(*tf->code),D);
-}
-
-static void DumpLocals(const Proto* tf, FILE* D)
-{
- int i,n=tf->nlocvars;
- DumpInt(n,D);
- for (i=0; i<n; i++)
- {
-  DumpString(tf->locvars[i].varname,D);
-  DumpInt(tf->locvars[i].startpc,D);
-  DumpInt(tf->locvars[i].endpc,D);
- }
-}
-
-static void DumpLines(const Proto* tf, FILE* D)
-{
- DumpInt(tf->nlineinfo,D);
- DumpVector(tf->lineinfo,tf->nlineinfo,sizeof(*tf->lineinfo),D);
-}
-
-static void DumpFunction(const Proto* tf, FILE* D);
-
-static void DumpConstants(const Proto* tf, FILE* D)
-{
- int i,n;
- DumpInt(n=tf->nkstr,D);
- for (i=0; i<n; i++)
-  DumpString(tf->kstr[i],D);
- DumpInt(tf->nknum,D);
- DumpVector(tf->knum,tf->nknum,sizeof(*tf->knum),D);
- DumpInt(n=tf->nkproto,D);
- for (i=0; i<n; i++)
-  DumpFunction(tf->kproto[i],D);
-}
-
-static void DumpFunction(const Proto* tf, FILE* D)
-{
- DumpString(tf->source,D);
- DumpInt(tf->lineDefined,D);
- DumpInt(tf->numparams,D);
- DumpByte(tf->is_vararg,D);
- DumpInt(tf->maxstacksize,D);
- DumpLocals(tf,D);
- DumpLines(tf,D);
- DumpConstants(tf,D);
- DumpCode(tf,D);
- if (ferror(D))
- {
-  perror("luac: write error");
-  exit(1);
- }
-}
-
-static void DumpHeader(FILE* D)
-{
- DumpByte(ID_CHUNK,D);
- fputs(SIGNATURE,D);
- DumpByte(VERSION,D);
- DumpByte(luaU_endianess(),D);
- DumpByte(sizeof(int),D);
- DumpByte(sizeof(size_t),D);
- DumpByte(sizeof(Instruction),D);
- DumpByte(SIZE_INSTRUCTION,D);
- DumpByte(SIZE_OP,D);
- DumpByte(SIZE_B,D);
- DumpByte(sizeof(Number),D);
- DumpNumber(TEST_NUMBER,D);
-}
-
-void luaU_dumpchunk(const Proto* Main, FILE* D)
-{
- DumpHeader(D);
- DumpFunction(Main,D);
-}
diff --git a/src/luac/luac.c b/src/luac/luac.c
index 8832de62..9ea23342 100644
--- a/src/luac/luac.c
+++ b/src/luac/luac.c
@@ -1,6 +1,6 @@
 /*
-** $Id: luac.c,v 1.28 2000/11/06 20:06:27 lhf Exp $
-** lua compiler (saves bytecodes to files; also list binary files)
+** $Id: luac.c,v 1.44 2003/04/07 20:34:20 lhf Exp $
+** Lua compiler (saves bytecodes to files; also list bytecodes)
 ** See Copyright Notice in lua.h
 */
 
@@ -8,78 +8,80 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "lparser.h"
-#include "lstate.h"
-#include "lzio.h"
-#include "luac.h"
+#include "lua.h"
+#include "lauxlib.h"
 
-#define	OUTPUT	"luac.out"		/* default output file */
+#include "lfunc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lstring.h"
+#include "lundump.h"
 
-static void usage(const char* message, const char* arg);
-static int doargs(int argc, const char* argv[]);
-static Proto* load(const char* filename);
-static FILE* efopen(const char* name, const char* mode);
-static void strip(Proto* tf);
-static Proto* combine(Proto** P, int n);
+#ifndef LUA_DEBUG
+#define luaB_opentests(L)
+#endif
 
-lua_State* lua_state=NULL;		/* lazy! */
+#ifndef PROGNAME
+#define PROGNAME	"luac"		/* program name */
+#endif
+
+#define	OUTPUT		"luac.out"	/* default output file */
 
 static int listing=0;			/* list bytecodes? */
 static int dumping=1;			/* dump bytecodes? */
 static int stripping=0;			/* strip debug information? */
-static int testing=0;			/* test integrity? */
-static const char* output=OUTPUT;	/* output file name */
+static char Output[]={ OUTPUT };	/* default output file name */
+static const char* output=Output;	/* output file name */
+static const char* progname=PROGNAME;	/* actual program name */
 
-#define	IS(s)	(strcmp(argv[i],s)==0)
+static void fatal(const char* message)
+{
+ fprintf(stderr,"%s: %s\n",progname,message);
+ exit(EXIT_FAILURE);
+}
 
-int main(int argc, const char* argv[])
+static void cannot(const char* name, const char* what, const char* mode)
 {
- Proto** P,*tf;
- int i=doargs(argc,argv);
- argc-=i; argv+=i;
- if (argc<=0) usage("no input files given",NULL);
- L=lua_open(0);
- P=luaM_newvector(L,argc,Proto*);
- for (i=0; i<argc; i++)
-  P[i]=load(IS("-")? NULL : argv[i]);
- tf=combine(P,argc);
- if (dumping) luaU_optchunk(tf);
- if (listing) luaU_printchunk(tf);
- if (testing) luaU_testchunk(tf);
- if (dumping)
- {
-  if (stripping) strip(tf);
-  luaU_dumpchunk(tf,efopen(output,"wb"));
- }
- return 0;
+ fprintf(stderr,"%s: cannot %s %sput file ",progname,what,mode);
+ perror(name);
+ exit(EXIT_FAILURE);
 }
 
 static void usage(const char* message, const char* arg)
 {
  if (message!=NULL)
  {
-  fprintf(stderr,"luac: "); fprintf(stderr,message,arg); fprintf(stderr,"\n");
+  fprintf(stderr,"%s: ",progname); fprintf(stderr,message,arg); fprintf(stderr,"\n");
  }
  fprintf(stderr,
- "usage: luac [options] [filenames].  Available options are:\n"
+ "usage: %s [options] [filenames].  Available options are:\n"
  "  -        process stdin\n"
  "  -l       list\n"
- "  -o file  output file (default is \"" OUTPUT "\")\n"
+ "  -o name  output to file `name' (default is \"" OUTPUT "\")\n"
  "  -p       parse only\n"
  "  -s       strip debug information\n"
- "  -t       test code integrity\n"
  "  -v       show version information\n"
- );
- exit(1);
+ "  --       stop handling options\n",
+ progname);
+ exit(EXIT_FAILURE);
 }
 
-static int doargs(int argc, const char* argv[])
+#define	IS(s)	(strcmp(argv[i],s)==0)
+
+static int doargs(int argc, char* argv[])
 {
  int i;
+ if (argv[0]!=NULL && *argv[0]!=0) progname=argv[0];
  for (i=1; i<argc; i++)
  {
-  if (*argv[i]!='-')			/* end of options */
+  if (*argv[i]!='-')			/* end of options; keep it */
+   break;
+  else if (IS("--"))			/* end of options; skip it */
+  {
+   ++i;
    break;
+  }
   else if (IS("-"))			/* end of options; use stdin */
    return i;
   else if (IS("-l"))			/* list */
@@ -87,117 +89,103 @@ static int doargs(int argc, const char* argv[])
   else if (IS("-o"))			/* output file */
   {
    output=argv[++i];
-   if (output==NULL) usage(NULL,NULL);
+   if (output==NULL || *output==0) usage("`-o' needs argument",NULL);
   }
   else if (IS("-p"))			/* parse only */
    dumping=0;
   else if (IS("-s"))			/* strip debug information */
    stripping=1;
-  else if (IS("-t"))			/* test */
-  {
-   testing=1;
-   dumping=0;
-  }
   else if (IS("-v"))			/* show version */
   {
    printf("%s  %s\n",LUA_VERSION,LUA_COPYRIGHT);
-   if (argc==2) exit(0);
+   if (argc==2) exit(EXIT_SUCCESS);
   }
   else					/* unknown option */
    usage("unrecognized option `%s'",argv[i]);
  }
- if (i==argc && (listing || testing))
+ if (i==argc && (listing || !dumping))
  {
   dumping=0;
-  argv[--i]=OUTPUT;
+  argv[--i]=Output;
  }
  return i;
 }
 
-static Proto* load(const char* filename)
+static Proto* toproto(lua_State* L, int i)
 {
- Proto* tf;
- ZIO z;
- char source[512];
- FILE* f;
- int c,undump;
- if (filename==NULL) 
- {
-  f=stdin;
-  filename="(stdin)";
- }
- else
-  f=efopen(filename,"r");
- c=ungetc(fgetc(f),f);
- if (ferror(f))
- {
-  fprintf(stderr,"luac: cannot read from ");
-  perror(filename);
-  exit(1);
- }
- undump=(c==ID_CHUNK);
- if (undump && f!=stdin)
- {
-  fclose(f);
-  f=efopen(filename,"rb");
- }
- sprintf(source,"@%.*s",Sizeof(source)-2,filename);
- luaZ_Fopen(&z,f,source);
- tf = undump ? luaU_undump(L,&z) : luaY_parser(L,&z);
- if (f!=stdin) fclose(f);
- return tf;
+ const Closure* c=(const Closure*)lua_topointer(L,i);
+ return c->l.p;
 }
 
-static Proto* combine(Proto** P, int n)
+static Proto* combine(lua_State* L, int n)
 {
  if (n==1)
-  return P[0];
+  return toproto(L,-1);
  else
  {
   int i,pc=0;
-  Proto* tf=luaF_newproto(L);
-  tf->source=luaS_new(L,"=(luac)");
-  tf->maxstacksize=1;
-  tf->kproto=P;
-  tf->nkproto=n;
-  tf->ncode=2*n+1;
-  tf->code=luaM_newvector(L,tf->ncode,Instruction);
+  Proto* f=luaF_newproto(L);
+  f->source=luaS_newliteral(L,"=(" PROGNAME ")");
+  f->maxstacksize=1;
+  f->p=luaM_newvector(L,n,Proto*);
+  f->sizep=n;
+  f->sizecode=2*n+1;
+  f->code=luaM_newvector(L,f->sizecode,Instruction);
   for (i=0; i<n; i++)
   {
-   tf->code[pc++]=CREATE_AB(OP_CLOSURE,i,0);
-   tf->code[pc++]=CREATE_AB(OP_CALL,0,0);
+   f->p[i]=toproto(L,i-n);
+   f->code[pc++]=CREATE_ABx(OP_CLOSURE,0,i);
+   f->code[pc++]=CREATE_ABC(OP_CALL,0,1,1);
   }
-  tf->code[pc++]=OP_END;
-  return tf;
+  f->code[pc++]=CREATE_ABC(OP_RETURN,0,1,0);
+  return f;
  }
 }
 
-static void strip(Proto* tf)
+static void strip(lua_State* L, Proto* f)
 {
- int i,n=tf->nkproto;
- tf->lineinfo=NULL;
- tf->nlineinfo=0;
- tf->source=luaS_new(L,"=(none)");
- tf->locvars=NULL;
- tf->nlocvars=0;
- for (i=0; i<n; i++) strip(tf->kproto[i]);
+ int i,n=f->sizep;
+ luaM_freearray(L, f->lineinfo, f->sizelineinfo, int);
+ luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar);
+ luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *);
+ f->lineinfo=NULL; f->sizelineinfo=0;
+ f->locvars=NULL;  f->sizelocvars=0;
+ f->upvalues=NULL; f->sizeupvalues=0;
+ f->source=luaS_newliteral(L,"=(none)");
+ for (i=0; i<n; i++) strip(L,f->p[i]);
 }
 
-static FILE* efopen(const char* name, const char* mode)
+static int writer(lua_State* L, const void* p, size_t size, void* u)
 {
- FILE* f=fopen(name,mode);
- if (f==NULL)
- {
-  fprintf(stderr,"luac: cannot open %sput file ",*mode=='r' ? "in" : "out");
-  perror(name);
-  exit(1);
- }
- return f; 
+ UNUSED(L);
+ return fwrite(p,size,1,(FILE*)u)==1;
 }
 
-void luaU_testchunk(const Proto* Main)
+int main(int argc, char* argv[])
 {
- UNUSED(Main);
- fprintf(stderr,"luac: -t not operational in this version\n");
- exit(1);
+ lua_State* L;
+ Proto* f;
+ int i=doargs(argc,argv);
+ argc-=i; argv+=i;
+ if (argc<=0) usage("no input files given",NULL);
+ L=lua_open();
+ luaB_opentests(L);
+ for (i=0; i<argc; i++)
+ {
+  const char* filename=IS("-") ? NULL : argv[i];
+  if (luaL_loadfile(L,filename)!=0) fatal(lua_tostring(L,-1));
+ }
+ f=combine(L,argc);
+ if (listing) luaU_print(f);
+ if (dumping)
+ {
+  FILE* D=fopen(output,"wb");
+  if (D==NULL) cannot(output,"open","out");
+  if (stripping) strip(L,f);
+  luaU_dump(L,f,writer,D);
+  if (ferror(D)) cannot(output,"write","out");
+  fclose(D);
+ }
+ lua_close(L);
+ return 0;
 }
diff --git a/src/luac/luac.h b/src/luac/luac.h
deleted file mode 100644
index f8987cf2..00000000
--- a/src/luac/luac.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
-** $Id: luac.h,v 1.18 2000/10/31 16:57:23 lhf Exp $
-** definitions for luac
-** See Copyright Notice in lua.h
-*/
-
-#include "ldebug.h"
-#include "lfunc.h"
-#include "lmem.h"
-#include "lobject.h"
-#include "lopcodes.h"
-#include "lstring.h"
-#include "ltable.h"
-#include "lundump.h"
-
-extern lua_State *lua_state;
-#define	L	lua_state		/* lazy! */
-
-/* from dump.c */
-void luaU_dumpchunk(const Proto* Main, FILE* D);
-
-/* from opt.c */
-void luaU_optchunk(Proto* Main);
-
-/* from print.c */
-void luaU_printchunk(const Proto* Main);
-
-/* from test.c */
-void luaU_testchunk(const Proto* Main);
-
-#define Sizeof(x)	((int)sizeof(x))
diff --git a/src/luac/opt.c b/src/luac/opt.c
deleted file mode 100644
index e51a0868..00000000
--- a/src/luac/opt.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
-** $Id: opt.c,v 1.22 2000/10/31 16:57:23 lhf Exp $
-** optimize bytecodes
-** See Copyright Notice in lua.h
-*/
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "luac.h"
-
-static int MapConstant(Hash* t, int j, const TObject* key)
-{
- const TObject* o=luaH_get(L,t,key);
- if (ttype(o)==LUA_TNUMBER)
-  return (int) nvalue(o);
- else
- {
-  TObject val;
-  ttype(&val)=LUA_TNUMBER;
-  nvalue(&val)=j;
-  *luaH_set(L,t,key)=val;
-  LUA_ASSERT(j>=0,"MapConstant returns negative!");
-  return j;
- }
-}
-
-static int MapConstants(Proto* tf, Hash* map)
-{
- int i,j,k,n,m=0;
- TObject o;
- j=0; n=tf->nknum; ttype(&o)=LUA_TNUMBER;
- for (i=0; i<n; i++)
- {
-  nvalue(&o)=tf->knum[i];
-  k=MapConstant(map,j,&o);
-  if (k==j) j++;
- }
- m=j;
- j=0; n=tf->nkstr; ttype(&o)=LUA_TSTRING;
- for (i=0; i<n; i++)
- {
-  tsvalue(&o)=tf->kstr[i];
-  k=MapConstant(map,j,&o);
-  if (k==j) j++;
- }
- return m+j;
-}
-
-static void PackConstants(Proto* tf, Hash* map)
-{
- int i,j,k,n;
- TObject o;
-#ifdef DEBUG
- printf("%p before pack nknum=%d nkstr=%d\n",tf,tf->nknum,tf->nkstr);
-#endif
- j=0; n=tf->nknum; ttype(&o)=LUA_TNUMBER;
- for (i=0; i<n; i++)
- {
-  nvalue(&o)=tf->knum[i];
-  k=MapConstant(map,-1,&o);
-  if (k==j) tf->knum[j++]=tf->knum[i];
- }
- tf->nknum=j;
- j=0; n=tf->nkstr; ttype(&o)=LUA_TSTRING;
- for (i=0; i<n; i++)
- {
-  tsvalue(&o)=tf->kstr[i];
-  k=MapConstant(map,-1,&o);
-  if (k==j) tf->kstr[j++]=tf->kstr[i];
- }
- tf->nkstr=j;
-#ifdef DEBUG
- printf("%p after  pack nknum=%d nkstr=%d\n",tf,tf->nknum,tf->nkstr);
-#endif
-}
-
-static void OptConstants(Proto* tf)
-{
- Instruction* p;
- int n=tf->nknum+tf->nkstr;
- Hash* map=luaH_new(L,n);
- int m=MapConstants(tf,map);
-#ifdef DEBUG
- printf("%p n=%d m=%d %s\n",tf,n,m,(m==n)?"nothing to optimize":"yes!");
-#endif
- if (m==n) return;
- for (p=tf->code;; p++)
- {
-  Instruction i=*p;
-  int op=GET_OPCODE(i);
-  switch (op)
-  {
-   TObject o;
-   int j,k;
-   case OP_PUSHNUM: case OP_PUSHNEGNUM:
-    j=GETARG_U(i);
-    ttype(&o)=LUA_TNUMBER; nvalue(&o)=tf->knum[j];
-    k=MapConstant(map,-1,&o);
-    if (k!=j) *p=CREATE_U(op,k);
-    break;
-   case OP_PUSHSTRING: case OP_GETGLOBAL: case OP_GETDOTTED:
-   case OP_PUSHSELF:   case OP_SETGLOBAL:
-    j=GETARG_U(i);
-    ttype(&o)=LUA_TSTRING; tsvalue(&o)=tf->kstr[j];
-    k=MapConstant(map,-1,&o);
-    if (k!=j) *p=CREATE_U(op,k);
-    break;
-   case OP_END:
-    PackConstants(tf,map);
-    luaH_free(L,map);
-    return;
-   default:
-    break;
-  }
- }
-}
-
-#define OptFunction luaU_optchunk
-
-void OptFunction(Proto* tf)
-{
- int i,n=tf->nkproto;
- OptConstants(tf);
- for (i=0; i<n; i++) OptFunction(tf->kproto[i]);
-}
diff --git a/src/luac/print.c b/src/luac/print.c
index 4ffc8b3d..d0b5efb2 100644
--- a/src/luac/print.c
+++ b/src/luac/print.c
@@ -1,31 +1,30 @@
 /*
-** $Id: print.c,v 1.32 2000/11/06 20:04:36 lhf Exp $
+** $Id: print.c,v 1.44 2003/04/07 20:34:20 lhf Exp $
 ** print bytecodes
 ** See Copyright Notice in lua.h
 */
 
 #include <stdio.h>
-#include <stdlib.h>
-
-#include "luac.h"
-
-/* macros used in print.h, included in PrintCode */
-#define P_OP(x)	printf("%-11s\t",x)
-#define P_NONE
-#define P_AB	printf("%d %d",GETARG_A(i),GETARG_B(i))
-#define P_F	printf("%d %d\t; %p",GETARG_A(i),GETARG_B(i),tf->kproto[GETARG_A(i)])
-#define P_J	printf("%d\t; to %d",GETARG_S(i),GETARG_S(i)+at+1)
-#define P_Q	PrintString(tf,GETARG_U(i))
-#define P_K	printf("%d\t; %s",GETARG_U(i),tf->kstr[GETARG_U(i)]->str)
-#define P_L	PrintLocal(tf,GETARG_U(i),at-1)
-#define P_N	printf("%d\t; " NUMBER_FMT,GETARG_U(i),tf->knum[GETARG_U(i)])
-#define P_S	printf("%d",GETARG_S(i))
-#define P_U	printf("%u",GETARG_U(i))
-
-static void PrintString(const Proto* tf, int n)
+
+#if 0
+#define DEBUG_PRINT
+#endif
+
+#ifndef LUA_OPNAMES
+#define LUA_OPNAMES
+#endif
+
+#include "ldebug.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lundump.h"
+
+#define Sizeof(x)	((int)sizeof(x))
+#define VOID(p)		((const void*)(p))
+
+static void PrintString(const Proto* f, int n)
 {
- const char* s=tf->kstr[n]->str;
- printf("%d\t; ",n);
+ const char* s=svalue(&f->k[n]);
  putchar('"');
  for (; *s; s++)
  {
@@ -45,55 +44,174 @@ static void PrintString(const Proto* tf, int n)
  putchar('"');
 }
 
-static void PrintLocal(const Proto* tf, int n, int pc)
+static void PrintConstant(const Proto* f, int i)
 {
- const char* s=luaF_getlocalname(tf,n+1,pc); 
- printf("%u",n);
- if (s!=NULL) printf("\t; %s",s);
+ const TObject* o=&f->k[i];
+ switch (ttype(o))
+ {
+  case LUA_TNUMBER:
+	printf(LUA_NUMBER_FMT,nvalue(o));
+	break;
+  case LUA_TSTRING:
+	PrintString(f,i);
+	break;
+  case LUA_TNIL:
+	printf("nil");
+	break;
+  default:				/* cannot happen */
+	printf("? type=%d",ttype(o));
+	break;
+ }
 }
 
-static void PrintCode(const Proto* tf)
+static void PrintCode(const Proto* f)
 {
- const Instruction* code=tf->code;
- const Instruction* p=code;
- for (;;)
+ const Instruction* code=f->code;
+ int pc,n=f->sizecode;
+ for (pc=0; pc<n; pc++)
  {
-  int at=p-code+1;
-  Instruction i=*p;
-  int line=luaG_getline(tf->lineinfo,at-1,1,NULL);
-  printf("%6d\t",at);
-  if (line>=0) printf("[%d]\t",line); else printf("[-]\t");
-  switch (GET_OPCODE(i)) {
-#include "print.h"
+  Instruction i=code[pc];
+  OpCode o=GET_OPCODE(i);
+  int a=GETARG_A(i);
+  int b=GETARG_B(i);
+  int c=GETARG_C(i);
+  int bc=GETARG_Bx(i);
+  int sbc=GETARG_sBx(i);
+  int line=getline(f,pc);
+#if 0
+  printf("%0*lX",Sizeof(i)*2,i);
+#endif
+  printf("\t%d\t",pc+1);
+  if (line>0) printf("[%d]\t",line); else printf("[-]\t");
+  printf("%-9s\t",luaP_opnames[o]);
+  switch (getOpMode(o))
+  {
+   case iABC:	printf("%d %d %d",a,b,c); break;
+   case iABx:	printf("%d %d",a,bc); break;
+   case iAsBx:	printf("%d %d",a,sbc); break;
+  }
+  switch (o)
+  {
+   case OP_LOADK:
+    printf("\t; "); PrintConstant(f,bc);
+    break;
+   case OP_GETUPVAL:
+   case OP_SETUPVAL:
+    printf("\t; %s", (f->sizeupvalues>0) ? getstr(f->upvalues[b]) : "-");
+    break;
+   case OP_GETGLOBAL:
+   case OP_SETGLOBAL:
+    printf("\t; %s",svalue(&f->k[bc]));
+    break;
+   case OP_GETTABLE:
+   case OP_SELF:
+    if (c>=MAXSTACK) { printf("\t; "); PrintConstant(f,c-MAXSTACK); }
+    break;
+   case OP_SETTABLE:
+   case OP_ADD:
+   case OP_SUB:
+   case OP_MUL:
+   case OP_DIV:
+   case OP_POW:
+   case OP_EQ:
+   case OP_LT:
+   case OP_LE:
+    if (b>=MAXSTACK || c>=MAXSTACK)
+    {
+     printf("\t; ");
+     if (b>=MAXSTACK) PrintConstant(f,b-MAXSTACK); else printf("-");
+     printf(" ");
+     if (c>=MAXSTACK) PrintConstant(f,c-MAXSTACK);
+    }
+    break;
+   case OP_JMP:
+   case OP_FORLOOP:
+   case OP_TFORPREP:
+    printf("\t; to %d",sbc+pc+2);
+    break;
+   case OP_CLOSURE:
+    printf("\t; %p",VOID(f->p[bc]));
+    break;
+   default:
+    break;
   }
   printf("\n");
-  if (i==OP_END) break;
-  p++;
  }
 }
 
-#define IsMain(tf)	(tf->lineDefined==0)
+static const char* Source(const Proto* f)
+{
+ const char* s=getstr(f->source);
+ if (*s=='@' || *s=='=')
+  return s+1;
+ else if (*s==LUA_SIGNATURE[0])
+  return "(bstring)";
+ else
+  return "(string)";
+}
+
+#define IsMain(f)	(f->lineDefined==0)
 
 #define SS(x)	(x==1)?"":"s"
 #define S(x)	x,SS(x)
 
-static void PrintHeader(const Proto* tf)
+static void PrintHeader(const Proto* f)
+{
+ printf("\n%s <%s:%d> (%d instruction%s, %d bytes at %p)\n",
+ 	IsMain(f)?"main":"function",Source(f),f->lineDefined,
+	S(f->sizecode),f->sizecode*Sizeof(Instruction),VOID(f));
+ printf("%d%s param%s, %d stack%s, %d upvalue%s, ",
+	f->numparams,f->is_vararg?"+":"",SS(f->numparams),S(f->maxstacksize),
+	S(f->nups));
+ printf("%d local%s, %d constant%s, %d function%s\n",
+	S(f->sizelocvars),S(f->sizek),S(f->sizep));
+}
+
+#ifdef DEBUG_PRINT
+static void PrintConstants(const Proto* f)
+{
+ int i,n=f->sizek;
+ printf("constants (%d) for %p:\n",n,VOID(f));
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t",i);
+  PrintConstant(f,i);
+  printf("\n");
+ }
+}
+
+static void PrintLocals(const Proto* f)
 {
- printf("\n%s " SOURCE_FMT " (%d instruction%s/%d bytes at %p)\n",
- 	IsMain(tf)?"main":"function",SOURCE,
-	S(tf->ncode),tf->ncode*Sizeof(Instruction),tf);
- printf("%d%s param%s, %d stack%s, ",
-	tf->numparams,tf->is_vararg?"+":"",SS(tf->numparams),S(tf->maxstacksize));
- printf("%d local%s, %d string%s, %d number%s, %d function%s, %d line%s\n",
-	S(tf->nlocvars),S(tf->nkstr),S(tf->nknum),S(tf->nkproto),S(tf->nlineinfo));
+ int i,n=f->sizelocvars;
+ printf("locals (%d) for %p:\n",n,VOID(f));
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t%s\t%d\t%d\n",
+  i,getstr(f->locvars[i].varname),f->locvars[i].startpc,f->locvars[i].endpc);
+ }
 }
 
-#define PrintFunction luaU_printchunk
+static void PrintUpvalues(const Proto* f)
+{
+ int i,n=f->sizeupvalues;
+ printf("upvalues (%d) for %p:\n",n,VOID(f));
+ if (f->upvalues==NULL) return;
+ for (i=0; i<n; i++)
+ {
+  printf("\t%d\t%s\n",i,getstr(f->upvalues[i]));
+ }
+}
+#endif
 
-void PrintFunction(const Proto* tf)
+void luaU_print(const Proto* f)
 {
- int i,n=tf->nkproto;
- PrintHeader(tf);
- PrintCode(tf);
- for (i=0; i<n; i++) PrintFunction(tf->kproto[i]);
+ int i,n=f->sizep;
+ PrintHeader(f);
+ PrintCode(f);
+#ifdef DEBUG_PRINT
+ PrintConstants(f);
+ PrintLocals(f);
+ PrintUpvalues(f);
+#endif
+ for (i=0; i<n; i++) luaU_print(f->p[i]);
 }
diff --git a/src/luac/print.h b/src/luac/print.h
deleted file mode 100644
index 5f74e149..00000000
--- a/src/luac/print.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
-** $Id: print.h,v 1.1 2000/11/06 20:03:12 lhf Exp $
-** extracted automatically from lopcodes.h by mkprint.lua -- DO NOT EDIT
-** See Copyright Notice in lua.h
-*/
-
-  case OP_END: P_OP("END"); P_NONE; break;
-  case OP_RETURN: P_OP("RETURN"); P_U; break;
-  case OP_CALL: P_OP("CALL"); P_AB; break;
-  case OP_TAILCALL: P_OP("TAILCALL"); P_AB; break;
-  case OP_PUSHNIL: P_OP("PUSHNIL"); P_U; break;
-  case OP_POP: P_OP("POP"); P_U; break;
-  case OP_PUSHINT: P_OP("PUSHINT"); P_S; break;
-  case OP_PUSHSTRING: P_OP("PUSHSTRING"); P_Q; break;
-  case OP_PUSHNUM: P_OP("PUSHNUM"); P_N; break;
-  case OP_PUSHNEGNUM: P_OP("PUSHNEGNUM"); P_N; break;
-  case OP_PUSHUPVALUE: P_OP("PUSHUPVALUE"); P_U; break;
-  case OP_GETLOCAL: P_OP("GETLOCAL"); P_L; break;
-  case OP_GETGLOBAL: P_OP("GETGLOBAL"); P_K; break;
-  case OP_GETTABLE: P_OP("GETTABLE"); P_NONE; break;
-  case OP_GETDOTTED: P_OP("GETDOTTED"); P_K; break;
-  case OP_GETINDEXED: P_OP("GETINDEXED"); P_L; break;
-  case OP_PUSHSELF: P_OP("PUSHSELF"); P_K; break;
-  case OP_CREATETABLE: P_OP("CREATETABLE"); P_U; break;
-  case OP_SETLOCAL: P_OP("SETLOCAL"); P_L; break;
-  case OP_SETGLOBAL: P_OP("SETGLOBAL"); P_K; break;
-  case OP_SETTABLE: P_OP("SETTABLE"); P_AB; break;
-  case OP_SETLIST: P_OP("SETLIST"); P_AB; break;
-  case OP_SETMAP: P_OP("SETMAP"); P_U; break;
-  case OP_ADD: P_OP("ADD"); P_NONE; break;
-  case OP_ADDI: P_OP("ADDI"); P_S; break;
-  case OP_SUB: P_OP("SUB"); P_NONE; break;
-  case OP_MULT: P_OP("MULT"); P_NONE; break;
-  case OP_DIV: P_OP("DIV"); P_NONE; break;
-  case OP_POW: P_OP("POW"); P_NONE; break;
-  case OP_CONCAT: P_OP("CONCAT"); P_U; break;
-  case OP_MINUS: P_OP("MINUS"); P_NONE; break;
-  case OP_NOT: P_OP("NOT"); P_NONE; break;
-  case OP_JMPNE: P_OP("JMPNE"); P_J; break;
-  case OP_JMPEQ: P_OP("JMPEQ"); P_J; break;
-  case OP_JMPLT: P_OP("JMPLT"); P_J; break;
-  case OP_JMPLE: P_OP("JMPLE"); P_J; break;
-  case OP_JMPGT: P_OP("JMPGT"); P_J; break;
-  case OP_JMPGE: P_OP("JMPGE"); P_J; break;
-  case OP_JMPT: P_OP("JMPT"); P_J; break;
-  case OP_JMPF: P_OP("JMPF"); P_J; break;
-  case OP_JMPONT: P_OP("JMPONT"); P_J; break;
-  case OP_JMPONF: P_OP("JMPONF"); P_J; break;
-  case OP_JMP: P_OP("JMP"); P_J; break;
-  case OP_PUSHNILJMP: P_OP("PUSHNILJMP"); P_NONE; break;
-  case OP_FORPREP: P_OP("FORPREP"); P_J; break;
-  case OP_FORLOOP: P_OP("FORLOOP"); P_J; break;
-  case OP_LFORPREP: P_OP("LFORPREP"); P_J; break;
-  case OP_LFORLOOP: P_OP("LFORLOOP"); P_J; break;
-  case OP_CLOSURE: P_OP("CLOSURE"); P_F; break;
diff --git a/src/luac/stubs.c b/src/luac/stubs.c
deleted file mode 100644
index 74f509eb..00000000
--- a/src/luac/stubs.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
-** $Id: stubs.c,v 1.20 2000/10/31 16:57:23 lhf Exp $
-** avoid runtime modules in luac
-** See Copyright Notice in lua.h
-*/
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "ldo.h"
-#include "llex.h"
-#include "luac.h"
-#undef L
-
-#ifndef NOSTUBS
-
-const char luac_ident[] = "$luac: " LUA_VERSION " " LUA_COPYRIGHT " $\n"
-                          "$Authors: " LUA_AUTHORS " $";
-
-/*
-* avoid lapi ldebug ldo lgc lstate ltm lvm
-* use only lcode lfunc llex lmem lobject lparser lstring ltable lzio
-*/
-
-/* simplified from ldo.c */
-void lua_error (lua_State* L, const char* s) {
-  UNUSED(L);
-  if (s) fprintf(stderr,"luac: %s\n",s);
-  exit(1);
-}
-
-/* simplified from ldo.c */
-void luaD_breakrun (lua_State *L, int errcode) {
-  UNUSED(errcode);
-  lua_error(L,"memory allocation error");
-}
-
-/* simplified from lstate.c */
-lua_State *lua_open (int stacksize) {
-  lua_State *L = luaM_new(NULL, lua_State);
-  if (L == NULL) return NULL;  /* memory allocation error */
-  L->stack = NULL;
-  L->strt.size = L->udt.size = 0;
-  L->strt.nuse = L->udt.nuse = 0;
-  L->strt.hash = NULL;
-  L->udt.hash = NULL;
-  L->Mbuffer = NULL;
-  L->Mbuffsize = 0;
-  L->rootproto = NULL;
-  L->rootcl = NULL;
-  L->roottable = NULL;
-  L->TMtable = NULL;
-  L->last_tag = -1;
-  L->refArray = NULL;
-  L->refSize = 0;
-  L->refFree = NONEXT;
-  L->nblocks = sizeof(lua_State);
-  L->GCthreshold = MAX_INT;  /* to avoid GC during pre-definitions */
-  L->callhook = NULL;
-  L->linehook = NULL;
-  L->allowhooks = 1;
-  L->errorJmp = NULL;
-  if (stacksize == 0)
-    stacksize = DEFAULT_STACK_SIZE;
-  else
-    stacksize += LUA_MINSTACK;
-  L->gt = luaH_new(L, 10);  /* table of globals */
-  luaS_init(L);
-  luaX_init(L);
-  L->GCthreshold = 2*L->nblocks;
-  return L;
-}
-
-/* copied from ldebug.c */
-int luaG_getline (int *lineinfo, int pc, int refline, int *prefi) {
-  int refi;
-  if (lineinfo == NULL || pc == -1)
-    return -1;  /* no line info or function is not active */
-  refi = prefi ? *prefi : 0;
-  if (lineinfo[refi] < 0)
-    refline += -lineinfo[refi++]; 
-  LUA_ASSERT(lineinfo[refi] >= 0, "invalid line info");
-  while (lineinfo[refi] > pc) {
-    refline--;
-    refi--;
-    if (lineinfo[refi] < 0)
-      refline -= -lineinfo[refi--]; 
-    LUA_ASSERT(lineinfo[refi] >= 0, "invalid line info");
-  }
-  for (;;) {
-    int nextline = refline + 1;
-    int nextref = refi + 1;
-    if (lineinfo[nextref] < 0)
-      nextline += -lineinfo[nextref++]; 
-    LUA_ASSERT(lineinfo[nextref] >= 0, "invalid line info");
-    if (lineinfo[nextref] > pc)
-      break;
-    refline = nextline;
-    refi = nextref;
-  }
-  if (prefi) *prefi = refi;
-  return refline;
-}
-
-/*
-* the code below avoids the lexer and the parser (llex lparser lcode).
-* it is useful if you only want to load binary files.
-* this works for interpreters like lua.c too.
-*/
-
-#ifdef NOPARSER
-
-#include "llex.h"
-#include "lparser.h"
-
-void luaX_init(lua_State *L) {
-  UNUSED(L);
-}
-
-Proto *luaY_parser(lua_State *L, ZIO *z) {
-  UNUSED(z);
-  lua_error(L,"parser not loaded");
-  return NULL;
-}
-
-#endif
-#endif
diff --git a/src/lundump.c b/src/lundump.c
index a8d06106..151a8507 100644
--- a/src/lundump.c
+++ b/src/lundump.c
@@ -1,243 +1,285 @@
 /*
-** $Id: lundump.c,v 1.33 2000/10/31 16:57:23 lhf Exp $
-** load bytecodes from files
+** $Id: lundump.c,v 1.49 2003/04/07 20:34:20 lhf Exp $
+** load pre-compiled Lua chunks
 ** See Copyright Notice in lua.h
 */
 
-#include <stdio.h>
-#include <string.h>
+#define lundump_c
 
+#include "lua.h"
+
+#include "ldebug.h"
 #include "lfunc.h"
 #include "lmem.h"
 #include "lopcodes.h"
 #include "lstring.h"
 #include "lundump.h"
+#include "lzio.h"
 
-#define	LoadByte		ezgetc
+#define	LoadByte	(lu_byte) ezgetc
 
-static const char* ZNAME (ZIO* Z)
-{
- const char* s=zname(Z);
- return (*s=='@') ? s+1 : s;
-}
+typedef struct {
+ lua_State* L;
+ ZIO* Z;
+ Mbuffer* b;
+ int swap;
+ const char* name;
+} LoadState;
 
-static void unexpectedEOZ (lua_State* L, ZIO* Z)
+static void unexpectedEOZ (LoadState* S)
 {
- luaO_verror(L,"unexpected end of file in `%.99s'",ZNAME(Z));
+ luaG_runerror(S->L,"unexpected end of file in %s",S->name);
 }
 
-static int ezgetc (lua_State* L, ZIO* Z)
+static int ezgetc (LoadState* S)
 {
- int c=zgetc(Z);
- if (c==EOZ) unexpectedEOZ(L,Z);
+ int c=zgetc(S->Z);
+ if (c==EOZ) unexpectedEOZ(S);
  return c;
 }
 
-static void ezread (lua_State* L, ZIO* Z, void* b, int n)
+static void ezread (LoadState* S, void* b, int n)
 {
- int r=zread(Z,b,n);
- if (r!=0) unexpectedEOZ(L,Z);
+ int r=luaZ_read(S->Z,b,n);
+ if (r!=0) unexpectedEOZ(S);
 }
 
-static void LoadBlock (lua_State* L, void* b, size_t size, ZIO* Z, int swap)
+static void LoadBlock (LoadState* S, void* b, size_t size)
 {
- if (swap)
+ if (S->swap)
  {
-  char *p=(char *) b+size-1;
+  char* p=(char*) b+size-1;
   int n=size;
-  while (n--) *p--=(char)ezgetc(L,Z);
+  while (n--) *p--=(char)ezgetc(S);
  }
  else
-  ezread(L,Z,b,size);
+  ezread(S,b,size);
 }
 
-static void LoadVector (lua_State* L, void* b, int m, size_t size, ZIO* Z, int swap)
+static void LoadVector (LoadState* S, void* b, int m, size_t size)
 {
- if (swap)
+ if (S->swap)
  {
-  char *q=(char *) b;
+  char* q=(char*) b;
   while (m--)
   {
-   char *p=q+size-1;
+   char* p=q+size-1;
    int n=size;
-   while (n--) *p--=(char)ezgetc(L,Z);
+   while (n--) *p--=(char)ezgetc(S);
    q+=size;
   }
  }
  else
-  ezread(L,Z,b,m*size);
+  ezread(S,b,m*size);
 }
 
-static int LoadInt (lua_State* L, ZIO* Z, int swap)
+static int LoadInt (LoadState* S)
 {
  int x;
- LoadBlock(L,&x,sizeof(x),Z,swap);
+ LoadBlock(S,&x,sizeof(x));
+ if (x<0) luaG_runerror(S->L,"bad integer in %s",S->name);
  return x;
 }
 
-static size_t LoadSize (lua_State* L, ZIO* Z, int swap)
+static size_t LoadSize (LoadState* S)
 {
  size_t x;
- LoadBlock(L,&x,sizeof(x),Z,swap);
+ LoadBlock(S,&x,sizeof(x));
  return x;
 }
 
-static Number LoadNumber (lua_State* L, ZIO* Z, int swap)
+static lua_Number LoadNumber (LoadState* S)
 {
- Number x;
- LoadBlock(L,&x,sizeof(x),Z,swap);
+ lua_Number x;
+ LoadBlock(S,&x,sizeof(x));
  return x;
 }
 
-static TString* LoadString (lua_State* L, ZIO* Z, int swap)
+static TString* LoadString (LoadState* S)
 {
- size_t size=LoadSize(L,Z,swap);
+ size_t size=LoadSize(S);
  if (size==0)
   return NULL;
  else
  {
-  char* s=luaO_openspace(L,size);
-  LoadBlock(L,s,size,Z,0);
-  return luaS_newlstr(L,s,size-1);	/* remove trailing '\0' */
+  char* s=luaZ_openspace(S->L,S->b,size);
+  ezread(S,s,size);
+  return luaS_newlstr(S->L,s,size-1);		/* remove trailing '\0' */
  }
 }
 
-static void LoadCode (lua_State* L, Proto* tf, ZIO* Z, int swap)
+static void LoadCode (LoadState* S, Proto* f)
 {
- int size=LoadInt(L,Z,swap);
- tf->code=luaM_newvector(L,size,Instruction);
- LoadVector(L,tf->code,size,sizeof(*tf->code),Z,swap);
- if (tf->code[size-1]!=OP_END) luaO_verror(L,"bad code in `%.99s'",ZNAME(Z));
- luaF_protook(L,tf,size);
+ int size=LoadInt(S);
+ f->code=luaM_newvector(S->L,size,Instruction);
+ f->sizecode=size;
+ LoadVector(S,f->code,size,sizeof(*f->code));
 }
 
-static void LoadLocals (lua_State* L, Proto* tf, ZIO* Z, int swap)
+static void LoadLocals (LoadState* S, Proto* f)
 {
  int i,n;
- tf->nlocvars=n=LoadInt(L,Z,swap);
- tf->locvars=luaM_newvector(L,n,LocVar);
+ n=LoadInt(S);
+ f->locvars=luaM_newvector(S->L,n,LocVar);
+ f->sizelocvars=n;
  for (i=0; i<n; i++)
  {
-  tf->locvars[i].varname=LoadString(L,Z,swap);
-  tf->locvars[i].startpc=LoadInt(L,Z,swap);
-  tf->locvars[i].endpc=LoadInt(L,Z,swap);
+  f->locvars[i].varname=LoadString(S);
+  f->locvars[i].startpc=LoadInt(S);
+  f->locvars[i].endpc=LoadInt(S);
  }
 }
 
-static void LoadLines (lua_State* L, Proto* tf, ZIO* Z, int swap)
+static void LoadLines (LoadState* S, Proto* f)
 {
- int n;
- tf->nlineinfo=n=LoadInt(L,Z,swap);
- tf->lineinfo=luaM_newvector(L,n,int);
- LoadVector(L,tf->lineinfo,n,sizeof(*tf->lineinfo),Z,swap);
+ int size=LoadInt(S);
+ f->lineinfo=luaM_newvector(S->L,size,int);
+ f->sizelineinfo=size;
+ LoadVector(S,f->lineinfo,size,sizeof(*f->lineinfo));
 }
 
-static Proto* LoadFunction (lua_State* L, ZIO* Z, int swap);
+static void LoadUpvalues (LoadState* S, Proto* f)
+{
+ int i,n;
+ n=LoadInt(S);
+ if (n!=0 && n!=f->nups) 
+  luaG_runerror(S->L,"bad nupvalues in %s: read %d; expected %d",
+		S->name,n,f->nups);
+ f->upvalues=luaM_newvector(S->L,n,TString*);
+ f->sizeupvalues=n;
+ for (i=0; i<n; i++) f->upvalues[i]=LoadString(S);
+}
 
-static void LoadConstants (lua_State* L, Proto* tf, ZIO* Z, int swap)
+static Proto* LoadFunction (LoadState* S, TString* p);
+
+static void LoadConstants (LoadState* S, Proto* f)
 {
  int i,n;
- tf->nkstr=n=LoadInt(L,Z,swap);
- tf->kstr=luaM_newvector(L,n,TString*);
- for (i=0; i<n; i++)
-  tf->kstr[i]=LoadString(L,Z,swap);
- tf->nknum=n=LoadInt(L,Z,swap);
- tf->knum=luaM_newvector(L,n,Number);
- LoadVector(L,tf->knum,n,sizeof(*tf->knum),Z,swap);
- tf->nkproto=n=LoadInt(L,Z,swap);
- tf->kproto=luaM_newvector(L,n,Proto*);
+ n=LoadInt(S);
+ f->k=luaM_newvector(S->L,n,TObject);
+ f->sizek=n;
  for (i=0; i<n; i++)
-  tf->kproto[i]=LoadFunction(L,Z,swap);
+ {
+  TObject* o=&f->k[i];
+  int t=LoadByte(S);
+  switch (t)
+  {
+   case LUA_TNUMBER:
+	setnvalue(o,LoadNumber(S));
+	break;
+   case LUA_TSTRING:
+	setsvalue2n(o,LoadString(S));
+	break;
+   case LUA_TNIL:
+   	setnilvalue(o);
+	break;
+   default:
+	luaG_runerror(S->L,"bad constant type (%d) in %s",t,S->name);
+	break;
+  }
+ }
+ n=LoadInt(S);
+ f->p=luaM_newvector(S->L,n,Proto*);
+ f->sizep=n;
+ for (i=0; i<n; i++) f->p[i]=LoadFunction(S,f->source);
 }
 
-static Proto* LoadFunction (lua_State* L, ZIO* Z, int swap)
+static Proto* LoadFunction (LoadState* S, TString* p)
 {
- Proto* tf=luaF_newproto(L);
- tf->source=LoadString(L,Z,swap);
- tf->lineDefined=LoadInt(L,Z,swap);
- tf->numparams=LoadInt(L,Z,swap);
- tf->is_vararg=LoadByte(L,Z);
- tf->maxstacksize=LoadInt(L,Z,swap);
- LoadLocals(L,tf,Z,swap);
- LoadLines(L,tf,Z,swap);
- LoadConstants(L,tf,Z,swap);
- LoadCode(L,tf,Z,swap);
- return tf;
+ Proto* f=luaF_newproto(S->L);
+ f->source=LoadString(S); if (f->source==NULL) f->source=p;
+ f->lineDefined=LoadInt(S);
+ f->nups=LoadByte(S);
+ f->numparams=LoadByte(S);
+ f->is_vararg=LoadByte(S);
+ f->maxstacksize=LoadByte(S);
+ LoadLines(S,f);
+ LoadLocals(S,f);
+ LoadUpvalues(S,f);
+ LoadConstants(S,f);
+ LoadCode(S,f);
+#ifndef TRUST_BINARIES
+ if (!luaG_checkcode(f)) luaG_runerror(S->L,"bad code in %s",S->name);
+#endif
+ return f;
 }
 
-static void LoadSignature (lua_State* L, ZIO* Z)
+static void LoadSignature (LoadState* S)
 {
- const char* s=SIGNATURE;
- while (*s!=0 && ezgetc(L,Z)==*s)
+ const char* s=LUA_SIGNATURE;
+ while (*s!=0 && ezgetc(S)==*s)
   ++s;
- if (*s!=0) luaO_verror(L,"bad signature in `%.99s'",ZNAME(Z));
+ if (*s!=0) luaG_runerror(S->L,"bad signature in %s",S->name);
 }
 
-static void TestSize (lua_State* L, int s, const char* what, ZIO* Z)
+static void TestSize (LoadState* S, int s, const char* what)
 {
- int r=ezgetc(L,Z);
+ int r=LoadByte(S);
  if (r!=s)
-  luaO_verror(L,"virtual machine mismatch in `%.99s':\n"
-	"  %.20s is %d but read %d",ZNAME(Z),what,s,r);
+  luaG_runerror(S->L,"virtual machine mismatch in %s: "
+	"size of %s is %d but read %d",S->name,what,s,r);
 }
 
-#define TESTSIZE(s)	TestSize(L,s,#s,Z)
-#define V(v)	v/16,v%16
+#define TESTSIZE(s,w)	TestSize(S,s,w)
+#define V(v)		v/16,v%16
 
-static int LoadHeader (lua_State* L, ZIO* Z)
+static void LoadHeader (LoadState* S)
 {
- int version,swap;
- Number f=0,tf=TEST_NUMBER;
- LoadSignature(L,Z);
- version=ezgetc(L,Z);
+ int version;
+ lua_Number x,tx=TEST_NUMBER;
+ LoadSignature(S);
+ version=LoadByte(S);
  if (version>VERSION)
-  luaO_verror(L,"`%.99s' too new:\n"
-	"  read version %d.%d; expected at most %d.%d",
-	ZNAME(Z),V(version),V(VERSION));
- if (version<VERSION0)			/* check last major change */
-  luaO_verror(L,"`%.99s' too old:\n"
-	"  read version %d.%d; expected at least %d.%d",
-	ZNAME(Z),V(version),V(VERSION));
- swap=(luaU_endianess()!=ezgetc(L,Z));	/* need to swap bytes? */
- TESTSIZE(sizeof(int));
- TESTSIZE(sizeof(size_t));
- TESTSIZE(sizeof(Instruction));
- TESTSIZE(SIZE_INSTRUCTION);
- TESTSIZE(SIZE_OP);
- TESTSIZE(SIZE_B);
- TESTSIZE(sizeof(Number));
- f=LoadNumber(L,Z,swap);
- if ((long)f!=(long)tf)		/* disregard errors in last bit of fraction */
-  luaO_verror(L,"unknown number format in `%.99s':\n"
-      "  read " NUMBER_FMT "; expected " NUMBER_FMT, ZNAME(Z),f,tf);
- return swap;
-}
-
-static Proto* LoadChunk (lua_State* L, ZIO* Z)
-{
- return LoadFunction(L,Z,LoadHeader(L,Z));
+  luaG_runerror(S->L,"%s too new: "
+	"read version %d.%d; expected at most %d.%d",
+	S->name,V(version),V(VERSION));
+ if (version<VERSION0)				/* check last major change */
+  luaG_runerror(S->L,"%s too old: "
+	"read version %d.%d; expected at least %d.%d",
+	S->name,V(version),V(VERSION0));
+ S->swap=(luaU_endianness()!=LoadByte(S));	/* need to swap bytes? */
+ TESTSIZE(sizeof(int),"int");
+ TESTSIZE(sizeof(size_t), "size_t");
+ TESTSIZE(sizeof(Instruction), "Instruction");
+ TESTSIZE(SIZE_OP, "OP");
+ TESTSIZE(SIZE_A, "A");
+ TESTSIZE(SIZE_B, "B");
+ TESTSIZE(SIZE_C, "C");
+ TESTSIZE(sizeof(lua_Number), "number");
+ x=LoadNumber(S);
+ if ((long)x!=(long)tx)		/* disregard errors in last bits of fraction */
+  luaG_runerror(S->L,"unknown number format in %s",S->name);
+}
+
+static Proto* LoadChunk (LoadState* S)
+{
+ LoadHeader(S);
+ return LoadFunction(S,NULL);
 }
 
 /*
-** load one chunk from a file or buffer
-** return main if ok and NULL at EOF
+** load precompiled chunk
 */
-Proto* luaU_undump (lua_State* L, ZIO* Z)
+Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff)
 {
- Proto* tf=NULL;
- int c=zgetc(Z);
- if (c==ID_CHUNK)
-  tf=LoadChunk(L,Z);
- c=zgetc(Z);
- if (c!=EOZ)
-  luaO_verror(L,"`%.99s' apparently contains more than one chunk",ZNAME(Z));
- return tf;
+ LoadState S;
+ const char* s=zname(Z);
+ if (*s=='@' || *s=='=')
+  S.name=s+1;
+ else if (*s==LUA_SIGNATURE[0])
+  S.name="binary string";
+ else
+  S.name=s;
+ S.L=L;
+ S.Z=Z;
+ S.b=buff;
+ return LoadChunk(&S);
 }
 
 /*
 ** find byte order
 */
-int luaU_endianess (void)
+int luaU_endianness (void)
 {
  int x=1;
  return *(char*)&x;
diff --git a/src/lundump.h b/src/lundump.h
index 446d2de9..c7e6959b 100644
--- a/src/lundump.h
+++ b/src/lundump.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.h,v 1.21 2000/10/31 16:57:23 lhf Exp $
+** $Id: lundump.h,v 1.30 2003/04/07 20:34:20 lhf Exp $
 ** load pre-compiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -10,26 +10,25 @@
 #include "lobject.h"
 #include "lzio.h"
 
-/* load one chunk */
-Proto* luaU_undump (lua_State* L, ZIO* Z);
+/* load one chunk; from lundump.c */
+Proto* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff);
 
-/* find byte order */
-int luaU_endianess (void);
+/* find byte order; from lundump.c */
+int luaU_endianness (void);
 
-/* definitions for headers of binary files */
-#define	VERSION		0x40		/* last format change was in 4.0 */
-#define	VERSION0	0x40		/* last major  change was in 4.0 */
-#define ID_CHUNK	27		/* binary files start with ESC... */
-#define	SIGNATURE	"Lua"		/* ...followed by this signature */
+/* dump one chunk; from ldump.c */
+void luaU_dump (lua_State* L, const Proto* Main, lua_Chunkwriter w, void* data);
+
+/* print one chunk; from print.c */
+void luaU_print (const Proto* Main);
 
-/* formats for error messages */
-#define SOURCE_FMT	"<%d:%.99s>"
-#define SOURCE		tf->lineDefined,tf->source->str
-#define IN_FMT		" in %p " SOURCE_FMT
-#define IN		tf,SOURCE
+/* definitions for headers of binary files */
+#define	LUA_SIGNATURE	"\033Lua"	/* binary files start with "<esc>Lua" */
+#define	VERSION		0x50		/* last format change was in 5.0 */
+#define	VERSION0	0x50		/* last major  change was in 5.0 */
 
 /* a multiple of PI for testing native format */
-/* multiplying by 1E8 gives non-trivial integer values */
-#define	TEST_NUMBER	3.14159265358979323846E8
+/* multiplying by 1E7 gives non-trivial integer values */
+#define	TEST_NUMBER	((lua_Number)3.14159265358979323846E7)
 
 #endif
diff --git a/src/lvm.c b/src/lvm.c
index 2a00b6a5..eaa5c700 100644
--- a/src/lvm.c
+++ b/src/lvm.c
@@ -1,17 +1,21 @@
 /*
-** $Id: lvm.c,v 1.146a 2000/10/26 12:47:05 roberto Exp $
+** $Id: lvm.c,v 1.284 2003/04/03 13:35:34 roberto Exp $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
 
 
-#include <stdio.h>
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 
+/* needed only when `lua_number2str' uses `sprintf' */
+#include <stdio.h>
+
+#define lvm_c
+
 #include "lua.h"
 
-#include "lapi.h"
 #include "ldebug.h"
 #include "ldo.h"
 #include "lfunc.h"
@@ -25,243 +29,225 @@
 #include "lvm.h"
 
 
-#ifdef OLD_ANSI
-#define strcoll(a,b)	strcmp(a,b)
-#endif
-
 
+/* function to convert a lua_Number to a string */
+#ifndef lua_number2str
+#define lua_number2str(s,n)     sprintf((s), LUA_NUMBER_FMT, (n))
+#endif
 
-/*
-** Extra stack size to run a function:
-** TAG_LINE(1), NAME(1), TM calls(3) (plus some extra...)
-*/
-#define	EXTRA_STACK	8
 
+/* limit for table tag-method chains (to avoid loops) */
+#define MAXTAGLOOP	100
 
 
-int luaV_tonumber (TObject *obj) {
-  if (ttype(obj) != LUA_TSTRING)
-    return 1;
-  else {
-    if (!luaO_str2d(svalue(obj), &nvalue(obj)))
-      return 2;
-    ttype(obj) = LUA_TNUMBER;
-    return 0;
+const TObject *luaV_tonumber (const TObject *obj, TObject *n) {
+  lua_Number num;
+  if (ttisnumber(obj)) return obj;
+  if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
+    setnvalue(n, num);
+    return n;
   }
+  else
+    return NULL;
 }
 
 
-int luaV_tostring (lua_State *L, TObject *obj) {  /* LUA_NUMBER */
-  if (ttype(obj) != LUA_TNUMBER)
-    return 1;
+int luaV_tostring (lua_State *L, StkId obj) {
+  if (!ttisnumber(obj))
+    return 0;
   else {
     char s[32];  /* 16 digits, sign, point and \0  (+ some extra...) */
-    lua_number2str(s, nvalue(obj));  /* convert `s' to number */
-    tsvalue(obj) = luaS_new(L, s);
-    ttype(obj) = LUA_TSTRING;
-    return 0;
+    lua_number2str(s, nvalue(obj));
+    setsvalue2s(obj, luaS_new(L, s));
+    return 1;
   }
 }
 
 
-static void traceexec (lua_State *L, StkId base, StkId top, lua_Hook linehook) {
-  CallInfo *ci = infovalue(base-1);
-  int *lineinfo = ci->func->f.l->lineinfo;
-  int pc = (*ci->pc - ci->func->f.l->code) - 1;
-  int newline;
-  if (pc == 0) {  /* may be first time? */
-    ci->line = 1;
-    ci->refi = 0;
-    ci->lastpc = pc+1;  /* make sure it will call linehook */
+static void traceexec (lua_State *L) {
+  lu_byte mask = L->hookmask;
+  if (mask > LUA_MASKLINE) {  /* instruction-hook set? */
+    if (L->hookcount == 0) {
+      resethookcount(L);
+      luaD_callhook(L, LUA_HOOKCOUNT, -1);
+      return;
+    }
   }
-  newline = luaG_getline(lineinfo, pc, ci->line, &ci->refi);
-  /* calls linehook when enters a new line or jumps back (loop) */
-  if (newline != ci->line || pc <= ci->lastpc) {
-    ci->line = newline;
-    L->top = top;
-    luaD_lineHook(L, base-1, newline, linehook);
+  if (mask & LUA_MASKLINE) {
+    CallInfo *ci = L->ci;
+    Proto *p = ci_func(ci)->l.p;
+    int newline = getline(p, pcRel(*ci->u.l.pc, p));
+    if (!L->hookinit) {
+      luaG_inithooks(L);
+      return;
+    }
+    lua_assert(ci->state & CI_HASFRAME);
+    if (pcRel(*ci->u.l.pc, p) == 0)  /* tracing may be starting now? */
+      ci->u.l.savedpc = *ci->u.l.pc;  /* initialize `savedpc' */
+    /* calls linehook when enters a new line or jumps back (loop) */
+    if (*ci->u.l.pc <= ci->u.l.savedpc ||
+        newline != getline(p, pcRel(ci->u.l.savedpc, p))) {
+      luaD_callhook(L, LUA_HOOKLINE, newline);
+      ci = L->ci;  /* previous call may reallocate `ci' */
+    }
+    ci->u.l.savedpc = *ci->u.l.pc;
   }
-  ci->lastpc = pc;
 }
 
 
-static Closure *luaV_closure (lua_State *L, int nelems) {
-  Closure *c = luaF_newclosure(L, nelems);
-  L->top -= nelems;
-  while (nelems--)
-    c->upvalue[nelems] = *(L->top+nelems);
-  clvalue(L->top) = c;
-  ttype(L->top) = LUA_TFUNCTION;
-  incr_top;
-  return c;
+static void callTMres (lua_State *L, const TObject *f,
+                       const TObject *p1, const TObject *p2) {
+  setobj2s(L->top, f);  /* push function */
+  setobj2s(L->top+1, p1);  /* 1st argument */
+  setobj2s(L->top+2, p2);  /* 2nd argument */
+  luaD_checkstack(L, 3);  /* cannot check before (could invalidate p1, p2) */
+  L->top += 3;
+  luaD_call(L, L->top - 3, 1);
+  L->top--;  /* result will be in L->top */
 }
 
 
-void luaV_Cclosure (lua_State *L, lua_CFunction c, int nelems) {
-  Closure *cl = luaV_closure(L, nelems);
-  cl->f.c = c;
-  cl->isC = 1;
+
+static void callTM (lua_State *L, const TObject *f,
+                    const TObject *p1, const TObject *p2, const TObject *p3) {
+  setobj2s(L->top, f);  /* push function */
+  setobj2s(L->top+1, p1);  /* 1st argument */
+  setobj2s(L->top+2, p2);  /* 2nd argument */
+  setobj2s(L->top+3, p3);  /* 3th argument */
+  luaD_checkstack(L, 4);  /* cannot check before (could invalidate p1...p3) */
+  L->top += 4;
+  luaD_call(L, L->top - 4, 0);
 }
 
 
-void luaV_Lclosure (lua_State *L, Proto *l, int nelems) {
-  Closure *cl = luaV_closure(L, nelems);
-  cl->f.l = l;
-  cl->isC = 0;
+static const TObject *luaV_index (lua_State *L, const TObject *t,
+                                  TObject *key, int loop) {
+  const TObject *tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);
+  if (tm == NULL) return &luaO_nilobject;  /* no TM */
+  if (ttisfunction(tm)) {
+    callTMres(L, tm, t, key);
+    return L->top;
+  }
+  else return luaV_gettable(L, tm, key, loop);
+}
+
+static const TObject *luaV_getnotable (lua_State *L, const TObject *t,
+                                       TObject *key, int loop) {
+  const TObject *tm = luaT_gettmbyobj(L, t, TM_INDEX);
+  if (ttisnil(tm))
+    luaG_typeerror(L, t, "index");
+  if (ttisfunction(tm)) {
+    callTMres(L, tm, t, key);
+    return L->top;
+  }
+  else return luaV_gettable(L, tm, key, loop);
 }
 
 
 /*
 ** Function to index a table.
-** Receives the table at `t' and the key at top.
+** Receives the table at `t' and the key at `key'.
+** leaves the result at `res'.
 */
-const TObject *luaV_gettable (lua_State *L, StkId t) {
-  Closure *tm;
-  int tg;
-  if (ttype(t) == LUA_TTABLE &&  /* `t' is a table? */
-      ((tg = hvalue(t)->htag) == LUA_TTABLE ||  /* with default tag? */
-        luaT_gettm(L, tg, TM_GETTABLE) == NULL)) { /* or no TM? */
-    /* do a primitive get */
-    const TObject *h = luaH_get(L, hvalue(t), L->top-1);
-    /* result is no nil or there is no `index' tag method? */
-    if (ttype(h) != LUA_TNIL || ((tm=luaT_gettm(L, tg, TM_INDEX)) == NULL))
-      return h;  /* return result */
-    /* else call `index' tag method */
-  }
-  else {  /* try a `gettable' tag method */
-    tm = luaT_gettmbyObj(L, t, TM_GETTABLE);
-  }
-  if (tm != NULL) {  /* is there a tag method? */
-    luaD_checkstack(L, 2);
-    *(L->top+1) = *(L->top-1);  /* key */
-    *L->top = *t;  /* table */
-    clvalue(L->top-1) = tm;  /* tag method */
-    ttype(L->top-1) = LUA_TFUNCTION;
-    L->top += 2;
-    luaD_call(L, L->top - 3, 1);
-    return L->top - 1;  /* call result */
-  }
-  else {  /* no tag method */
-    luaG_typeerror(L, t, "index");
-    return NULL;  /* to avoid warnings */
+const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key,
+                              int loop) {
+  if (loop > MAXTAGLOOP)
+    luaG_runerror(L, "loop in gettable");
+  if (ttistable(t)) {  /* `t' is a table? */
+    Table *h = hvalue(t);
+    const TObject *v = luaH_get(h, key);  /* do a primitive get */
+    if (!ttisnil(v)) return v;
+    else return luaV_index(L, t, key, loop+1);
   }
+  else return luaV_getnotable(L, t, key, loop+1);
 }
 
 
 /*
-** Receives table at `t', key at `key' and value at top.
+** Receives table at `t', key at `key' and value at `val'.
 */
-void luaV_settable (lua_State *L, StkId t, StkId key) {
-  int tg;
-  if (ttype(t) == LUA_TTABLE &&  /* `t' is a table? */
-      ((tg = hvalue(t)->htag) == LUA_TTABLE ||  /* with default tag? */
-        luaT_gettm(L, tg, TM_SETTABLE) == NULL)) /* or no TM? */
-    *luaH_set(L, hvalue(t), key) = *(L->top-1);  /* do a primitive set */
-  else {  /* try a `settable' tag method */
-    Closure *tm = luaT_gettmbyObj(L, t, TM_SETTABLE);
-    if (tm != NULL) {
-      luaD_checkstack(L, 3);
-      *(L->top+2) = *(L->top-1);
-      *(L->top+1) = *key;
-      *(L->top) = *t;
-      clvalue(L->top-1) = tm;
-      ttype(L->top-1) = LUA_TFUNCTION;
-      L->top += 3;
-      luaD_call(L, L->top - 4, 0);  /* call `settable' tag method */
+void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
+  const TObject *tm;
+  int loop = 0;
+  do {
+    if (ttistable(t)) {  /* `t' is a table? */
+      Table *h = hvalue(t);
+      TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
+      if (!ttisnil(oldval) ||  /* result is no nil? */
+          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
+        setobj2t(oldval, val);  /* write barrier */
+        return;
+      }
+      /* else will try the tag method */
     }
-    else  /* no tag method... */
+    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
       luaG_typeerror(L, t, "index");
-  }
-}
-
-
-const TObject *luaV_getglobal (lua_State *L, TString *s) {
-  const TObject *value = luaH_getstr(L->gt, s);
-  Closure *tm = luaT_gettmbyObj(L, value, TM_GETGLOBAL);
-  if (tm == NULL)  /* is there a tag method? */
-    return value;  /* default behavior */
-  else {  /* tag method */
-    luaD_checkstack(L, 3);
-    clvalue(L->top) = tm;
-    ttype(L->top) = LUA_TFUNCTION;
-    tsvalue(L->top+1) = s;  /* global name */
-    ttype(L->top+1) = LUA_TSTRING;
-    *(L->top+2) = *value;
-    L->top += 3;
-    luaD_call(L, L->top - 3, 1);
-    return L->top - 1;
-  }
+    if (ttisfunction(tm)) {
+      callTM(L, tm, t, key, val);
+      return;
+    }
+    t = tm;  /* else repeat with `tm' */ 
+  } while (++loop <= MAXTAGLOOP);
+  luaG_runerror(L, "loop in settable");
 }
 
 
-void luaV_setglobal (lua_State *L, TString *s) {
-  const TObject *oldvalue = luaH_getstr(L->gt, s);
-  Closure *tm = luaT_gettmbyObj(L, oldvalue, TM_SETGLOBAL);
-  if (tm == NULL) {  /* is there a tag method? */
-    if (oldvalue != &luaO_nilobject) {
-      /* cast to remove `const' is OK, because `oldvalue' != luaO_nilobject */
-      *(TObject *)oldvalue = *(L->top - 1);
-    }
-    else {
-      TObject key;
-      ttype(&key) = LUA_TSTRING;
-      tsvalue(&key) = s;
-      *luaH_set(L, L->gt, &key) = *(L->top - 1);
-    }
-  }
-  else {
-    luaD_checkstack(L, 3);
-    *(L->top+2) = *(L->top-1);  /* new value */
-    *(L->top+1) = *oldvalue;
-    ttype(L->top) = LUA_TSTRING;
-    tsvalue(L->top) = s;
-    clvalue(L->top-1) = tm;
-    ttype(L->top-1) = LUA_TFUNCTION;
-    L->top += 3;
-    luaD_call(L, L->top - 4, 0);
-  }
+static int call_binTM (lua_State *L, const TObject *p1, const TObject *p2,
+                       StkId res, TMS event) {
+  ptrdiff_t result = savestack(L, res);
+  const TObject *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
+  if (ttisnil(tm))
+    tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
+  if (!ttisfunction(tm)) return 0;
+  callTMres(L, tm, p1, p2);
+  res = restorestack(L, result);  /* previous call may change stack */
+  setobjs2s(res, L->top);
+  return 1;
 }
 
 
-static int call_binTM (lua_State *L, StkId top, TMS event) {
-  /* try first operand */
-  Closure *tm = luaT_gettmbyObj(L, top-2, event);
-  L->top = top;
-  if (tm == NULL) {
-    tm = luaT_gettmbyObj(L, top-1, event);  /* try second operand */
-    if (tm == NULL) {
-      tm = luaT_gettm(L, 0, event);  /* try a `global' method */
-      if (tm == NULL)
-        return 0;  /* error */
-    }
-  }
-  lua_pushstring(L, luaT_eventname[event]);
-  luaD_callTM(L, tm, 3, 1);
-  return 1;
+static const TObject *get_compTM (lua_State *L, Table *mt1, Table *mt2,
+                                  TMS event) {
+  const TObject *tm1 = fasttm(L, mt1, event);
+  const TObject *tm2;
+  if (tm1 == NULL) return NULL;  /* no metamethod */
+  if (mt1 == mt2) return tm1;  /* same metatables => same metamethods */
+  tm2 = fasttm(L, mt2, event);
+  if (tm2 == NULL) return NULL;  /* no metamethod */
+  if (luaO_rawequalObj(tm1, tm2))  /* same metamethods? */
+    return tm1;
+  return NULL;
 }
 
 
-static void call_arith (lua_State *L, StkId top, TMS event) {
-  if (!call_binTM(L, top, event))
-    luaG_binerror(L, top-2, LUA_TNUMBER, "perform arithmetic on");
+static int call_orderTM (lua_State *L, const TObject *p1, const TObject *p2,
+                         TMS event) {
+  const TObject *tm1 = luaT_gettmbyobj(L, p1, event);
+  const TObject *tm2;
+  if (ttisnil(tm1)) return -1;  /* no metamethod? */
+  tm2 = luaT_gettmbyobj(L, p2, event);
+  if (!luaO_rawequalObj(tm1, tm2))  /* different metamethods? */
+    return -1;
+  callTMres(L, tm1, p1, p2);
+  return !l_isfalse(L->top);
 }
 
 
-static int luaV_strcomp (const TString *ls, const TString *rs) {
-  const char *l = ls->str;
-  size_t ll = ls->len;
-  const char *r = rs->str;
-  size_t lr = rs->len;
+static int luaV_strcmp (const TString *ls, const TString *rs) {
+  const char *l = getstr(ls);
+  size_t ll = ls->tsv.len;
+  const char *r = getstr(rs);
+  size_t lr = rs->tsv.len;
   for (;;) {
     int temp = strcoll(l, r);
     if (temp != 0) return temp;
-    else {  /* strings are equal up to a '\0' */
-      size_t len = strlen(l);  /* index of first '\0' in both strings */
-      if (len == ll)  /* l is finished? */
-        return (len == lr) ? 0 : -1;  /* l is equal or smaller than r */
-      else if (len == lr)  /* r is finished? */
-        return 1;  /* l is greater than r (because l is not finished) */
-      /* both strings longer than `len'; go on comparing (after the '\0') */
+    else {  /* strings are equal up to a `\0' */
+      size_t len = strlen(l);  /* index of first `\0' in both strings */
+      if (len == lr)  /* r is finished? */
+        return (len == ll) ? 0 : 1;
+      else if (len == ll)  /* l is finished? */
+        return -1;  /* l is smaller than r (because r is not finished) */
+      /* both strings longer than `len'; go on comparing (after the `\0') */
       len++;
       l += len; ll -= len; r += len; lr -= len;
     }
@@ -269,442 +255,526 @@ static int luaV_strcomp (const TString *ls, const TString *rs) {
 }
 
 
-int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r, StkId top) {
-  if (ttype(l) == LUA_TNUMBER && ttype(r) == LUA_TNUMBER)
-    return (nvalue(l) < nvalue(r));
-  else if (ttype(l) == LUA_TSTRING && ttype(r) == LUA_TSTRING)
-    return (luaV_strcomp(tsvalue(l), tsvalue(r)) < 0);
-  else {  /* call TM */
-    luaD_checkstack(L, 2);
-    *top++ = *l;
-    *top++ = *r;
-    if (!call_binTM(L, top, TM_LT))
-      luaG_ordererror(L, top-2);
-    L->top--;
-    return (ttype(L->top) != LUA_TNIL);
+int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r) {
+  int res;
+  if (ttype(l) != ttype(r))
+    return luaG_ordererror(L, l, r);
+  else if (ttisnumber(l))
+    return nvalue(l) < nvalue(r);
+  else if (ttisstring(l))
+    return luaV_strcmp(tsvalue(l), tsvalue(r)) < 0;
+  else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
+    return res;
+  return luaG_ordererror(L, l, r);
+}
+
+
+static int luaV_lessequal (lua_State *L, const TObject *l, const TObject *r) {
+  int res;
+  if (ttype(l) != ttype(r))
+    return luaG_ordererror(L, l, r);
+  else if (ttisnumber(l))
+    return nvalue(l) <= nvalue(r);
+  else if (ttisstring(l))
+    return luaV_strcmp(tsvalue(l), tsvalue(r)) <= 0;
+  else if ((res = call_orderTM(L, l, r, TM_LE)) != -1)  /* first try `le' */
+    return res;
+  else if ((res = call_orderTM(L, r, l, TM_LT)) != -1)  /* else try `lt' */
+    return !res;
+  return luaG_ordererror(L, l, r);
+}
+
+
+int luaV_equalval (lua_State *L, const TObject *t1, const TObject *t2) {
+  const TObject *tm;
+  lua_assert(ttype(t1) == ttype(t2));
+  switch (ttype(t1)) {
+    case LUA_TNIL: return 1;
+    case LUA_TNUMBER: return nvalue(t1) == nvalue(t2);
+    case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
+    case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
+    case LUA_TUSERDATA: {
+      if (uvalue(t1) == uvalue(t2)) return 1;
+      tm = get_compTM(L, uvalue(t1)->uv.metatable, uvalue(t2)->uv.metatable,
+                         TM_EQ);
+      break;  /* will try TM */
+    }
+    case LUA_TTABLE: {
+      if (hvalue(t1) == hvalue(t2)) return 1;
+      tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
+      break;  /* will try TM */
+    }
+    default: return gcvalue(t1) == gcvalue(t2);
   }
+  if (tm == NULL) return 0;  /* no TM? */
+  callTMres(L, tm, t1, t2);  /* call TM */
+  return !l_isfalse(L->top);
 }
 
 
-void luaV_strconc (lua_State *L, int total, StkId top) {
+void luaV_concat (lua_State *L, int total, int last) {
   do {
+    StkId top = L->base + last + 1;
     int n = 2;  /* number of elements handled in this pass (at least 2) */
-    if (tostring(L, top-2) || tostring(L, top-1)) {
-      if (!call_binTM(L, top, TM_CONCAT))
-        luaG_binerror(L, top-2, LUA_TSTRING, "concat");
-    }
-    else if (tsvalue(top-1)->len > 0) {  /* if len=0, do nothing */
+    if (!tostring(L, top-2) || !tostring(L, top-1)) {
+      if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
+        luaG_concaterror(L, top-2, top-1);
+    } else if (tsvalue(top-1)->tsv.len > 0) {  /* if len=0, do nothing */
       /* at least two string values; get as many as possible */
-      lint32 tl = (lint32)tsvalue(top-1)->len + 
-                  (lint32)tsvalue(top-2)->len;
+      lu_mem tl = cast(lu_mem, tsvalue(top-1)->tsv.len) +
+                  cast(lu_mem, tsvalue(top-2)->tsv.len);
       char *buffer;
       int i;
-      while (n < total && !tostring(L, top-n-1)) {  /* collect total length */
-        tl += tsvalue(top-n-1)->len;
+      while (n < total && tostring(L, top-n-1)) {  /* collect total length */
+        tl += tsvalue(top-n-1)->tsv.len;
         n++;
       }
-      if (tl > MAX_SIZET) lua_error(L, "string size overflow");
-      buffer = luaO_openspace(L, tl);
+      if (tl > MAX_SIZET) luaG_runerror(L, "string size overflow");
+      buffer = luaZ_openspace(L, &G(L)->buff, tl);
       tl = 0;
       for (i=n; i>0; i--) {  /* concat all strings */
-        size_t l = tsvalue(top-i)->len;
-        memcpy(buffer+tl, tsvalue(top-i)->str, l);
+        size_t l = tsvalue(top-i)->tsv.len;
+        memcpy(buffer+tl, svalue(top-i), l);
         tl += l;
       }
-      tsvalue(top-n) = luaS_newlstr(L, buffer, tl);
+      setsvalue2s(top-n, luaS_newlstr(L, buffer, tl));
     }
     total -= n-1;  /* got `n' strings to create 1 new */
-    top -= n-1;
+    last -= n-1;
   } while (total > 1);  /* repeat until only 1 result left */
 }
 
 
-static void luaV_pack (lua_State *L, StkId firstelem) {
-  int i;
-  Hash *htab = luaH_new(L, 0);
-  for (i=0; firstelem+i<L->top; i++)
-    *luaH_setint(L, htab, i+1) = *(firstelem+i);
-  /* store counter in field `n' */
-  luaH_setstrnum(L, htab, luaS_new(L, "n"), i);
-  L->top = firstelem;  /* remove elements from the stack */
-  ttype(L->top) = LUA_TTABLE;
-  hvalue(L->top) = htab;
-  incr_top;
-}
-
-
-static void adjust_varargs (lua_State *L, StkId base, int nfixargs) {
-  int nvararg = (L->top-base) - nfixargs;
-  if (nvararg < 0)
-    luaD_adjusttop(L, base, nfixargs);
-  luaV_pack(L, base+nfixargs);
+static void Arith (lua_State *L, StkId ra,
+                   const TObject *rb, const TObject *rc, TMS op) {
+  TObject tempb, tempc;
+  const TObject *b, *c;
+  if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
+      (c = luaV_tonumber(rc, &tempc)) != NULL) {
+    switch (op) {
+      case TM_ADD: setnvalue(ra, nvalue(b) + nvalue(c)); break;
+      case TM_SUB: setnvalue(ra, nvalue(b) - nvalue(c)); break;
+      case TM_MUL: setnvalue(ra, nvalue(b) * nvalue(c)); break;
+      case TM_DIV: setnvalue(ra, nvalue(b) / nvalue(c)); break;
+      case TM_POW: {
+        const TObject *f = luaH_getstr(hvalue(gt(L)), G(L)->tmname[TM_POW]);
+        ptrdiff_t res = savestack(L, ra);
+        if (!ttisfunction(f))
+          luaG_runerror(L, "`__pow' (`^' operator) is not a function");
+        callTMres(L, f, b, c);
+        ra = restorestack(L, res);  /* previous call may change stack */
+        setobjs2s(ra, L->top);
+        break;
+      }
+      default: lua_assert(0); break;
+    }
+  }
+  else if (!call_binTM(L, rb, rc, ra, op))
+    luaG_aritherror(L, rb, rc);
 }
 
 
 
-#define dojump(pc, i)	{ int d = GETARG_S(i); pc += d; }
-
 /*
-** Executes the given Lua function. Parameters are between [base,top).
-** Returns n such that the the results are between [n,top).
+** some macros for common tasks in `luaV_execute'
 */
-StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
-  const Proto *const tf = cl->f.l;
-  StkId top;  /* keep top local, for performance */
-  const Instruction *pc = tf->code;
-  TString **const kstr = tf->kstr;
-  const lua_Hook linehook = L->linehook;
-  infovalue(base-1)->pc = &pc;
-  luaD_checkstack(L, tf->maxstacksize+EXTRA_STACK);
-  if (tf->is_vararg)  /* varargs? */
-    adjust_varargs(L, base, tf->numparams);
-  else
-    luaD_adjusttop(L, base, tf->numparams);
-  top = L->top;
+
+#define runtime_check(L, c)	{ if (!(c)) return 0; }
+
+#define RA(i)	(base+GETARG_A(i))
+/* to be used after possible stack reallocation */
+#define XRA(i)	(L->base+GETARG_A(i))
+#define RB(i)	(base+GETARG_B(i))
+#define RKB(i)	((GETARG_B(i) < MAXSTACK) ? RB(i) : k+GETARG_B(i)-MAXSTACK)
+#define RC(i)	(base+GETARG_C(i))
+#define RKC(i)	((GETARG_C(i) < MAXSTACK) ? RC(i) : k+GETARG_C(i)-MAXSTACK)
+#define KBx(i)	(k+GETARG_Bx(i))
+
+
+#define dojump(pc, i)	((pc) += (i))
+
+
+StkId luaV_execute (lua_State *L) {
+  LClosure *cl;
+  TObject *k;
+  const Instruction *pc;
+ callentry:  /* entry point when calling new functions */
+  L->ci->u.l.pc = &pc;
+  if (L->hookmask & LUA_MASKCALL)
+    luaD_callhook(L, LUA_HOOKCALL, -1);
+ retentry:  /* entry point when returning to old functions */
+  lua_assert(L->ci->state == CI_SAVEDPC ||
+             L->ci->state == (CI_SAVEDPC | CI_CALLING));
+  L->ci->state = CI_HASFRAME;  /* activate frame */
+  pc = L->ci->u.l.savedpc;
+  cl = &clvalue(L->base - 1)->l;
+  k = cl->p->k;
   /* main loop of interpreter */
   for (;;) {
     const Instruction i = *pc++;
-    if (linehook)
-      traceexec(L, base, top, linehook);
-    switch (GET_OPCODE(i)) {
-      case OP_END: {
-        L->top = top;
-        return top;
+    StkId base, ra;
+    if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
+        (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
+      traceexec(L);
+      if (L->ci->state & CI_YIELD) {  /* did hook yield? */
+        L->ci->u.l.savedpc = pc - 1;
+        L->ci->state = CI_YIELD | CI_SAVEDPC;
+        return NULL;
       }
-      case OP_RETURN: {
-        L->top = top;
-        return base+GETARG_U(i);
-      }
-      case OP_CALL: {
-        int nres = GETARG_B(i);
-        if (nres == MULT_RET) nres = LUA_MULTRET;
-        L->top = top;
-        luaD_call(L, base+GETARG_A(i), nres);
-        top = L->top;
-        break;
-      }
-      case OP_TAILCALL: {
-        L->top = top;
-        luaD_call(L, base+GETARG_A(i), LUA_MULTRET);
-        return base+GETARG_B(i);
-      }
-      case OP_PUSHNIL: {
-        int n = GETARG_U(i);
-        LUA_ASSERT(n>0, "invalid argument");
-        do {
-          ttype(top++) = LUA_TNIL;
-        } while (--n > 0);
-        break;
-      }
-      case OP_POP: {
-        top -= GETARG_U(i);
-        break;
-      }
-      case OP_PUSHINT: {
-        ttype(top) = LUA_TNUMBER;
-        nvalue(top) = (Number)GETARG_S(i);
-        top++;
-        break;
-      }
-      case OP_PUSHSTRING: {
-        ttype(top) = LUA_TSTRING;
-        tsvalue(top) = kstr[GETARG_U(i)];
-        top++;
+    }
+    /* warning!! several calls may realloc the stack and invalidate `ra' */
+    base = L->base;
+    ra = RA(i);
+    lua_assert(L->ci->state & CI_HASFRAME);
+    lua_assert(base == L->ci->base);
+    lua_assert(L->top <= L->stack + L->stacksize && L->top >= base);
+    lua_assert(L->top == L->ci->top ||
+         GET_OPCODE(i) == OP_CALL ||   GET_OPCODE(i) == OP_TAILCALL ||
+         GET_OPCODE(i) == OP_RETURN || GET_OPCODE(i) == OP_SETLISTO);
+    switch (GET_OPCODE(i)) {
+      case OP_MOVE: {
+        setobjs2s(ra, RB(i));
         break;
       }
-      case OP_PUSHNUM: {
-        ttype(top) = LUA_TNUMBER;
-        nvalue(top) = tf->knum[GETARG_U(i)];
-        top++;
+      case OP_LOADK: {
+        setobj2s(ra, KBx(i));
         break;
       }
-      case OP_PUSHNEGNUM: {
-        ttype(top) = LUA_TNUMBER;
-        nvalue(top) = -tf->knum[GETARG_U(i)];
-        top++;
+      case OP_LOADBOOL: {
+        setbvalue(ra, GETARG_B(i));
+        if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
         break;
       }
-      case OP_PUSHUPVALUE: {
-        *top++ = cl->upvalue[GETARG_U(i)];
+      case OP_LOADNIL: {
+        TObject *rb = RB(i);
+        do {
+          setnilvalue(rb--);
+        } while (rb >= ra);
         break;
       }
-      case OP_GETLOCAL: {
-        *top++ = *(base+GETARG_U(i));
+      case OP_GETUPVAL: {
+        int b = GETARG_B(i);
+        setobj2s(ra, cl->upvals[b]->v);
         break;
       }
       case OP_GETGLOBAL: {
-        L->top = top;
-        *top = *luaV_getglobal(L, kstr[GETARG_U(i)]);
-        top++;
+        TObject *rb = KBx(i);
+        const TObject *v;
+        lua_assert(ttisstring(rb) && ttistable(&cl->g));
+        v = luaH_getstr(hvalue(&cl->g), tsvalue(rb));
+        if (!ttisnil(v)) { setobj2s(ra, v); }
+        else
+          setobj2s(XRA(i), luaV_index(L, &cl->g, rb, 0));
         break;
       }
       case OP_GETTABLE: {
-        L->top = top;
-        top--;
-        *(top-1) = *luaV_gettable(L, top-1);
+        StkId rb = RB(i);
+        TObject *rc = RKC(i);
+        if (ttistable(rb)) {
+          const TObject *v = luaH_get(hvalue(rb), rc);
+          if (!ttisnil(v)) { setobj2s(ra, v); }
+          else
+            setobj2s(XRA(i), luaV_index(L, rb, rc, 0));
+        }
+        else
+          setobj2s(XRA(i), luaV_getnotable(L, rb, rc, 0));
         break;
       }
-      case OP_GETDOTTED: {
-        ttype(top) = LUA_TSTRING;
-        tsvalue(top) = kstr[GETARG_U(i)];
-        L->top = top+1;
-        *(top-1) = *luaV_gettable(L, top-1);
+      case OP_SETGLOBAL: {
+        lua_assert(ttisstring(KBx(i)) && ttistable(&cl->g));
+        luaV_settable(L, &cl->g, KBx(i), ra);
         break;
       }
-      case OP_GETINDEXED: {
-        *top = *(base+GETARG_U(i));
-        L->top = top+1;
-        *(top-1) = *luaV_gettable(L, top-1);
+      case OP_SETUPVAL: {
+        int b = GETARG_B(i);
+        setobj(cl->upvals[b]->v, ra);  /* write barrier */
         break;
       }
-      case OP_PUSHSELF: {
-        TObject receiver;
-        receiver = *(top-1);
-        ttype(top) = LUA_TSTRING;
-        tsvalue(top++) = kstr[GETARG_U(i)];
-        L->top = top;
-        *(top-2) = *luaV_gettable(L, top-2);
-        *(top-1) = receiver;
+      case OP_SETTABLE: {
+        luaV_settable(L, ra, RKB(i), RKC(i));
         break;
       }
-      case OP_CREATETABLE: {
-        L->top = top;
+      case OP_NEWTABLE: {
+        int b = GETARG_B(i);
+        b = fb2int(b);
+        sethvalue(ra, luaH_new(L, b, GETARG_C(i)));
         luaC_checkGC(L);
-        hvalue(top) = luaH_new(L, GETARG_U(i));
-        ttype(top) = LUA_TTABLE;
-        top++;
-        break;
-      }
-      case OP_SETLOCAL: {
-        *(base+GETARG_U(i)) = *(--top);
-        break;
-      }
-      case OP_SETGLOBAL: {
-        L->top = top;
-        luaV_setglobal(L, kstr[GETARG_U(i)]);
-        top--;
         break;
       }
-      case OP_SETTABLE: {
-        StkId t = top-GETARG_A(i);
-        L->top = top;
-        luaV_settable(L, t, t+1);
-        top -= GETARG_B(i);  /* pop values */
-        break;
-      }
-      case OP_SETLIST: {
-        int aux = GETARG_A(i) * LFIELDS_PER_FLUSH;
-        int n = GETARG_B(i);
-        Hash *arr = hvalue(top-n-1);
-        L->top = top-n;  /* final value of `top' (in case of errors) */
-        for (; n; n--)
-          *luaH_setint(L, arr, n+aux) = *(--top);
-        break;
-      }
-      case OP_SETMAP: {
-        int n = GETARG_U(i);
-        StkId finaltop = top-2*n;
-        Hash *arr = hvalue(finaltop-1);
-        L->top = finaltop;  /* final value of `top' (in case of errors) */
-        for (; n; n--) {
-          top-=2;
-          *luaH_set(L, arr, top) = *(top+1);
+      case OP_SELF: {
+        StkId rb = RB(i);
+        TObject *rc = RKC(i);
+        runtime_check(L, ttisstring(rc));
+        setobjs2s(ra+1, rb);
+        if (ttistable(rb)) {
+          const TObject *v = luaH_getstr(hvalue(rb), tsvalue(rc));
+          if (!ttisnil(v)) { setobj2s(ra, v); }
+          else
+            setobj2s(XRA(i), luaV_index(L, rb, rc, 0));
         }
-        break;
-      }
-      case OP_ADD: {
-        if (tonumber(top-2) || tonumber(top-1))
-          call_arith(L, top, TM_ADD);
         else
-          nvalue(top-2) += nvalue(top-1);
-        top--;
+          setobj2s(XRA(i), luaV_getnotable(L, rb, rc, 0));
         break;
       }
-      case OP_ADDI: {
-        if (tonumber(top-1)) {
-          ttype(top) = LUA_TNUMBER;
-          nvalue(top) = (Number)GETARG_S(i);
-          call_arith(L, top+1, TM_ADD);
+      case OP_ADD: {
+        TObject *rb = RKB(i);
+        TObject *rc = RKC(i);
+        if (ttisnumber(rb) && ttisnumber(rc)) {
+          setnvalue(ra, nvalue(rb) + nvalue(rc));
         }
         else
-          nvalue(top-1) += (Number)GETARG_S(i);
+          Arith(L, ra, rb, rc, TM_ADD);
         break;
       }
       case OP_SUB: {
-        if (tonumber(top-2) || tonumber(top-1))
-          call_arith(L, top, TM_SUB);
+        TObject *rb = RKB(i);
+        TObject *rc = RKC(i);
+        if (ttisnumber(rb) && ttisnumber(rc)) {
+          setnvalue(ra, nvalue(rb) - nvalue(rc));
+        }
         else
-          nvalue(top-2) -= nvalue(top-1);
-        top--;
+          Arith(L, ra, rb, rc, TM_SUB);
         break;
       }
-      case OP_MULT: {
-        if (tonumber(top-2) || tonumber(top-1))
-          call_arith(L, top, TM_MUL);
+      case OP_MUL: {
+        TObject *rb = RKB(i);
+        TObject *rc = RKC(i);
+        if (ttisnumber(rb) && ttisnumber(rc)) {
+          setnvalue(ra, nvalue(rb) * nvalue(rc));
+        }
         else
-          nvalue(top-2) *= nvalue(top-1);
-        top--;
+          Arith(L, ra, rb, rc, TM_MUL);
         break;
       }
       case OP_DIV: {
-        if (tonumber(top-2) || tonumber(top-1))
-          call_arith(L, top, TM_DIV);
+        TObject *rb = RKB(i);
+        TObject *rc = RKC(i);
+        if (ttisnumber(rb) && ttisnumber(rc)) {
+          setnvalue(ra, nvalue(rb) / nvalue(rc));
+        }
         else
-          nvalue(top-2) /= nvalue(top-1);
-        top--;
+          Arith(L, ra, rb, rc, TM_DIV);
         break;
       }
       case OP_POW: {
-        if (!call_binTM(L, top, TM_POW))
-          lua_error(L, "undefined operation");
-        top--;
-        break;
-      }
-      case OP_CONCAT: {
-        int n = GETARG_U(i);
-        luaV_strconc(L, n, top);
-        top -= n-1;
-        L->top = top;
-        luaC_checkGC(L);
+        Arith(L, ra, RKB(i), RKC(i), TM_POW);
         break;
       }
-      case OP_MINUS: {
-        if (tonumber(top-1)) {
-          ttype(top) = LUA_TNIL;
-          call_arith(L, top+1, TM_UNM);
+      case OP_UNM: {
+        const TObject *rb = RB(i);
+        TObject temp;
+        if (tonumber(rb, &temp)) {
+          setnvalue(ra, -nvalue(rb));
+        }
+        else {
+          setnilvalue(&temp);
+          if (!call_binTM(L, RB(i), &temp, ra, TM_UNM))
+            luaG_aritherror(L, RB(i), &temp);
         }
-        else
-          nvalue(top-1) = -nvalue(top-1);
         break;
       }
       case OP_NOT: {
-        ttype(top-1) =
-           (ttype(top-1) == LUA_TNIL) ? LUA_TNUMBER : LUA_TNIL;
-        nvalue(top-1) = 1;
-        break;
-      }
-      case OP_JMPNE: {
-        top -= 2;
-        if (!luaO_equalObj(top, top+1)) dojump(pc, i);
-        break;
-      }
-      case OP_JMPEQ: {
-        top -= 2;
-        if (luaO_equalObj(top, top+1)) dojump(pc, i);
+        int res = l_isfalse(RB(i));  /* next assignment may change this value */
+        setbvalue(ra, res);
         break;
       }
-      case OP_JMPLT: {
-        top -= 2;
-        if (luaV_lessthan(L, top, top+1, top+2)) dojump(pc, i);
+      case OP_CONCAT: {
+        int b = GETARG_B(i);
+        int c = GETARG_C(i);
+        luaV_concat(L, c-b+1, c);  /* may change `base' (and `ra') */
+        base = L->base;
+        setobjs2s(RA(i), base+b);
+        luaC_checkGC(L);
         break;
       }
-      case OP_JMPLE: {  /* a <= b  ===  !(b<a) */
-        top -= 2;
-        if (!luaV_lessthan(L, top+1, top, top+2)) dojump(pc, i);
+      case OP_JMP: {
+        dojump(pc, GETARG_sBx(i));
         break;
       }
-      case OP_JMPGT: {  /* a > b  ===  (b<a) */
-        top -= 2;
-        if (luaV_lessthan(L, top+1, top, top+2)) dojump(pc, i);
+      case OP_EQ: {
+        if (equalobj(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+        else dojump(pc, GETARG_sBx(*pc) + 1);
         break;
       }
-      case OP_JMPGE: {  /* a >= b  ===  !(a<b) */
-        top -= 2;
-        if (!luaV_lessthan(L, top, top+1, top+2)) dojump(pc, i);
+      case OP_LT: {
+        if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+        else dojump(pc, GETARG_sBx(*pc) + 1);
         break;
       }
-      case OP_JMPT: {
-        if (ttype(--top) != LUA_TNIL) dojump(pc, i);
+      case OP_LE: {
+        if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+        else dojump(pc, GETARG_sBx(*pc) + 1);
         break;
       }
-      case OP_JMPF: {
-        if (ttype(--top) == LUA_TNIL) dojump(pc, i);
+      case OP_TEST: {
+        TObject *rb = RB(i);
+        if (l_isfalse(rb) == GETARG_C(i)) pc++;
+        else {
+          setobjs2s(ra, rb);
+          dojump(pc, GETARG_sBx(*pc) + 1);
+        }
         break;
       }
-      case OP_JMPONT: {
-        if (ttype(top-1) == LUA_TNIL) top--;
-        else dojump(pc, i);
+      case OP_CALL:
+      case OP_TAILCALL: {
+        StkId firstResult;
+        int b = GETARG_B(i);
+        int nresults;
+        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
+        nresults = GETARG_C(i) - 1;
+        firstResult = luaD_precall(L, ra);
+        if (firstResult) {
+          if (firstResult > L->top) {  /* yield? */
+            lua_assert(L->ci->state == (CI_C | CI_YIELD));
+            (L->ci - 1)->u.l.savedpc = pc;
+            (L->ci - 1)->state = CI_SAVEDPC;
+            return NULL;
+          }
+          /* it was a C function (`precall' called it); adjust results */
+          luaD_poscall(L, nresults, firstResult);
+          if (nresults >= 0) L->top = L->ci->top;
+        }
+        else {  /* it is a Lua function */
+          if (GET_OPCODE(i) == OP_CALL) {  /* regular call? */
+            (L->ci-1)->u.l.savedpc = pc;  /* save `pc' to return later */
+            (L->ci-1)->state = (CI_SAVEDPC | CI_CALLING);
+          }
+          else {  /* tail call: put new frame in place of previous one */
+            int aux;
+            base = (L->ci - 1)->base;  /* `luaD_precall' may change the stack */
+            ra = RA(i);
+            if (L->openupval) luaF_close(L, base);
+            for (aux = 0; ra+aux < L->top; aux++)  /* move frame down */
+              setobjs2s(base+aux-1, ra+aux);
+            (L->ci - 1)->top = L->top = base+aux;  /* correct top */
+            lua_assert(L->ci->state & CI_SAVEDPC);
+            (L->ci - 1)->u.l.savedpc = L->ci->u.l.savedpc;
+            (L->ci - 1)->u.l.tailcalls++;  /* one more call lost */
+            (L->ci - 1)->state = CI_SAVEDPC;
+            L->ci--;  /* remove new frame */
+            L->base = L->ci->base;
+          }
+          goto callentry;
+        }
         break;
       }
-      case OP_JMPONF: {
-        if (ttype(top-1) != LUA_TNIL) top--;
-        else dojump(pc, i);
-        break;
+      case OP_RETURN: {
+        CallInfo *ci = L->ci - 1;  /* previous function frame */
+        int b = GETARG_B(i);
+        if (b != 0) L->top = ra+b-1;
+        lua_assert(L->ci->state & CI_HASFRAME);
+        if (L->openupval) luaF_close(L, base);
+        L->ci->state = CI_SAVEDPC;  /* deactivate current function */
+        L->ci->u.l.savedpc = pc;
+        /* previous function was running `here'? */
+        if (!(ci->state & CI_CALLING)) {
+          lua_assert((ci->state & CI_C) || ci->u.l.pc != &pc);
+          return ra;  /* no: return */
+        }
+        else {  /* yes: continue its execution */
+          int nresults;
+          lua_assert(ci->u.l.pc == &pc &&
+                     ttisfunction(ci->base - 1) &&
+                     (ci->state & CI_SAVEDPC));
+          lua_assert(GET_OPCODE(*(ci->u.l.savedpc - 1)) == OP_CALL);
+          nresults = GETARG_C(*(ci->u.l.savedpc - 1)) - 1;
+          luaD_poscall(L, nresults, ra);
+          if (nresults >= 0) L->top = L->ci->top;
+          goto retentry;
+        }
       }
-      case OP_JMP: {
-        dojump(pc, i);
-        break;
-      }
-      case OP_PUSHNILJMP: {
-        ttype(top++) = LUA_TNIL;
-        pc++;
-        break;
-      }
-      case OP_FORPREP: {
-        if (tonumber(top-1))
-          lua_error(L, "`for' step must be a number");
-        if (tonumber(top-2))
-          lua_error(L, "`for' limit must be a number");
-        if (tonumber(top-3))
-          lua_error(L, "`for' initial value must be a number");
-        if (nvalue(top-1) > 0 ?
-            nvalue(top-3) > nvalue(top-2) :
-            nvalue(top-3) < nvalue(top-2)) {  /* `empty' loop? */
-          top -= 3;  /* remove control variables */
-          dojump(pc, i);  /* jump to loop end */
+      case OP_FORLOOP: {
+        lua_Number step, idx, limit;
+        const TObject *plimit = ra+1;
+        const TObject *pstep = ra+2;
+        if (!ttisnumber(ra))
+          luaG_runerror(L, "`for' initial value must be a number");
+        if (!tonumber(plimit, ra+1))
+          luaG_runerror(L, "`for' limit must be a number");
+        if (!tonumber(pstep, ra+2))
+          luaG_runerror(L, "`for' step must be a number");
+        step = nvalue(pstep);
+        idx = nvalue(ra) + step;  /* increment index */
+        limit = nvalue(plimit);
+        if (step > 0 ? idx <= limit : idx >= limit) {
+          dojump(pc, GETARG_sBx(i));  /* jump back */
+          chgnvalue(ra, idx);  /* update index */
         }
         break;
       }
-      case OP_FORLOOP: {
-        LUA_ASSERT(ttype(top-1) == LUA_TNUMBER, "invalid step");
-        LUA_ASSERT(ttype(top-2) == LUA_TNUMBER, "invalid limit");
-        if (ttype(top-3) != LUA_TNUMBER)
-          lua_error(L, "`for' index must be a number");
-        nvalue(top-3) += nvalue(top-1);  /* increment index */
-        if (nvalue(top-1) > 0 ?
-            nvalue(top-3) > nvalue(top-2) :
-            nvalue(top-3) < nvalue(top-2))
-          top -= 3;  /* end loop: remove control variables */
+      case OP_TFORLOOP: {
+        int nvar = GETARG_C(i) + 1;
+        StkId cb = ra + nvar + 2;  /* call base */
+        setobjs2s(cb, ra);
+        setobjs2s(cb+1, ra+1);
+        setobjs2s(cb+2, ra+2);
+        L->top = cb+3;  /* func. + 2 args (state and index) */
+        luaD_call(L, cb, nvar);
+        L->top = L->ci->top;
+        ra = XRA(i) + 2;  /* final position of first result */
+        cb = ra + nvar;
+        do {  /* move results to proper positions */
+          nvar--;
+          setobjs2s(ra+nvar, cb+nvar);
+        } while (nvar > 0);
+        if (ttisnil(ra))  /* break loop? */
+          pc++;  /* skip jump (break loop) */
         else
-          dojump(pc, i);  /* repeat loop */
+          dojump(pc, GETARG_sBx(*pc) + 1);  /* jump back */
         break;
       }
-      case OP_LFORPREP: {
-        Node *node;
-        if (ttype(top-1) != LUA_TTABLE)
-          lua_error(L, "`for' table must be a table");
-        node = luaH_next(L, hvalue(top-1), &luaO_nilobject);
-        if (node == NULL) {  /* `empty' loop? */
-          top--;  /* remove table */
-          dojump(pc, i);  /* jump to loop end */
+      case OP_TFORPREP: {  /* for compatibility only */
+        if (ttistable(ra)) {
+          setobjs2s(ra+1, ra);
+          setobj2s(ra, luaH_getstr(hvalue(gt(L)), luaS_new(L, "next")));
         }
+        dojump(pc, GETARG_sBx(i));
+        break;
+      }
+      case OP_SETLIST:
+      case OP_SETLISTO: {
+        int bc;
+        int n;
+        Table *h;
+        runtime_check(L, ttistable(ra));
+        h = hvalue(ra);
+        bc = GETARG_Bx(i);
+        if (GET_OPCODE(i) == OP_SETLIST)
+          n = (bc&(LFIELDS_PER_FLUSH-1)) + 1;
         else {
-          top += 2;  /* index,value */
-          *(top-2) = *key(node);
-          *(top-1) = *val(node);
+          n = L->top - ra - 1;
+          L->top = L->ci->top;
         }
+        bc &= ~(LFIELDS_PER_FLUSH-1);  /* bc = bc - bc%FPF */
+        for (; n > 0; n--)
+          setobj2t(luaH_setnum(L, h, bc+n), ra+n);  /* write barrier */
         break;
       }
-      case OP_LFORLOOP: {
-        Node *node;
-        LUA_ASSERT(ttype(top-3) == LUA_TTABLE, "invalid table");
-        node = luaH_next(L, hvalue(top-3), top-2);
-        if (node == NULL)  /* end loop? */
-          top -= 3;  /* remove table, key, and value */
-        else {
-          *(top-2) = *key(node);
-          *(top-1) = *val(node);
-          dojump(pc, i);  /* repeat loop */
-        }
+      case OP_CLOSE: {
+        luaF_close(L, ra);
         break;
       }
       case OP_CLOSURE: {
-        L->top = top;
-        luaV_Lclosure(L, tf->kproto[GETARG_A(i)], GETARG_B(i));
-        top = L->top;
+        Proto *p;
+        Closure *ncl;
+        int nup, j;
+        p = cl->p->p[GETARG_Bx(i)];
+        nup = p->nups;
+        ncl = luaF_newLclosure(L, nup, &cl->g);
+        ncl->l.p = p;
+        for (j=0; j<nup; j++, pc++) {
+          if (GET_OPCODE(*pc) == OP_GETUPVAL)
+            ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
+          else {
+            lua_assert(GET_OPCODE(*pc) == OP_MOVE);
+            ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
+          }
+        }
+        setclvalue(ra, ncl);
         luaC_checkGC(L);
         break;
       }
     }
   }
 }
+
diff --git a/src/lvm.h b/src/lvm.h
index ace07c82..19cce200 100644
--- a/src/lvm.h
+++ b/src/lvm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.h,v 1.27 2000/10/05 12:14:08 roberto Exp $
+** $Id: lvm.h,v 1.47 2002/11/14 16:16:21 roberto Exp $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -13,20 +13,23 @@
 #include "ltm.h"
 
 
-#define tonumber(o)   ((ttype(o) != LUA_TNUMBER) && (luaV_tonumber(o) != 0))
-#define tostring(L,o) ((ttype(o) != LUA_TSTRING) && (luaV_tostring(L, o) != 0))
+#define tostring(L,o) ((ttype(o) == LUA_TSTRING) || (luaV_tostring(L, o)))
 
+#define tonumber(o,n)	(ttype(o) == LUA_TNUMBER || \
+                         (((o) = luaV_tonumber(o,n)) != NULL))
 
-int luaV_tonumber (TObject *obj);
-int luaV_tostring (lua_State *L, TObject *obj);
-const TObject *luaV_gettable (lua_State *L, StkId t);
-void luaV_settable (lua_State *L, StkId t, StkId key);
-const TObject *luaV_getglobal (lua_State *L, TString *s);
-void luaV_setglobal (lua_State *L, TString *s);
-StkId luaV_execute (lua_State *L, const Closure *cl, StkId base);
-void luaV_Cclosure (lua_State *L, lua_CFunction c, int nelems);
-void luaV_Lclosure (lua_State *L, Proto *l, int nelems);
-int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r, StkId top);
-void luaV_strconc (lua_State *L, int total, StkId top);
+#define equalobj(L,o1,o2) \
+	(ttype(o1) == ttype(o2) && luaV_equalval(L, o1, o2))
+
+
+int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r);
+int luaV_equalval (lua_State *L, const TObject *t1, const TObject *t2);
+const TObject *luaV_tonumber (const TObject *obj, TObject *n);
+int luaV_tostring (lua_State *L, StkId obj);
+const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key,
+                              int loop);
+void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val);
+StkId luaV_execute (lua_State *L);
+void luaV_concat (lua_State *L, int total, int last);
 
 #endif
diff --git a/src/lzio.c b/src/lzio.c
index c958fe46..3aeca1c5 100644
--- a/src/lzio.c
+++ b/src/lzio.c
@@ -1,77 +1,62 @@
 /*
-** $Id: lzio.c,v 1.13 2000/06/12 13:52:05 roberto Exp $
+** $Id: lzio.c,v 1.24 2003/03/20 16:00:56 roberto Exp $
 ** a generic input stream interface
 ** See Copyright Notice in lua.h
 */
 
 
-
-#include <stdio.h>
 #include <string.h>
 
+#define lzio_c
+
 #include "lua.h"
 
+#include "llimits.h"
+#include "lmem.h"
 #include "lzio.h"
 
 
-
-/* ----------------------------------------------------- memory buffers --- */
-
-static int zmfilbuf (ZIO* z) {
-  (void)z;  /* to avoid warnings */
-  return EOZ;
-}
-
-
-ZIO* zmopen (ZIO* z, const char* b, size_t size, const char *name) {
-  if (b==NULL) return NULL;
-  z->n = size;
-  z->p = (const unsigned char *)b;
-  z->filbuf = zmfilbuf;
-  z->u = NULL;
-  z->name = name;
-  return z;
+int luaZ_fill (ZIO *z) {
+  size_t size;
+  const char *buff = z->reader(NULL, z->data, &size);
+  if (buff == NULL || size == 0) return EOZ;
+  z->n = size - 1;
+  z->p = buff;
+  return char2int(*(z->p++));
 }
 
-/* ------------------------------------------------------------ strings --- */
-
-ZIO* zsopen (ZIO* z, const char* s, const char *name) {
-  if (s==NULL) return NULL;
-  return zmopen(z, s, strlen(s), name);
-}
 
-/* -------------------------------------------------------------- FILEs --- */
-
-static int zffilbuf (ZIO* z) {
-  size_t n;
-  if (feof((FILE *)z->u)) return EOZ;
-  n = fread(z->buffer, 1, ZBSIZE, (FILE *)z->u);
-  if (n==0) return EOZ;
-  z->n = n-1;
-  z->p = z->buffer;
-  return *(z->p++);
+int luaZ_lookahead (ZIO *z) {
+  if (z->n == 0) {
+    int c = luaZ_fill(z);
+    if (c == EOZ) return c;
+    z->n++;
+    z->p--;
+  }
+  return char2int(*z->p);
 }
 
 
-ZIO* zFopen (ZIO* z, FILE* f, const char *name) {
-  if (f==NULL) return NULL;
-  z->n = 0;
-  z->p = z->buffer;
-  z->filbuf = zffilbuf;
-  z->u = f;
+void luaZ_init (ZIO *z, lua_Chunkreader reader, void *data, const char *name) {
+  z->reader = reader;
+  z->data = data;
   z->name = name;
-  return z;
+  z->n = 0;
+  z->p = NULL;
 }
 
 
 /* --------------------------------------------------------------- read --- */
-size_t zread (ZIO *z, void *b, size_t n) {
+size_t luaZ_read (ZIO *z, void *b, size_t n) {
   while (n) {
     size_t m;
     if (z->n == 0) {
-      if (z->filbuf(z) == EOZ)
+      if (luaZ_fill(z) == EOZ)
         return n;  /* return number of missing bytes */
-      zungetc(z);  /* put result from `filbuf' in the buffer */
+      else {
+        ++z->n;  /* filbuf removed first byte; put back it */
+        --z->p;
+      }
     }
     m = (n <= z->n) ? n : z->n;  /* min. between n and z->n */
     memcpy(b, z->p, m);
@@ -82,3 +67,15 @@ size_t zread (ZIO *z, void *b, size_t n) {
   }
   return 0;
 }
+
+/* ------------------------------------------------------------------------ */
+char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
+  if (n > buff->buffsize) {
+    if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
+    luaM_reallocvector(L, buff->buffer, buff->buffsize, n, char);
+    buff->buffsize = n;
+  }
+  return buff->buffer;
+}
+
+
diff --git a/src/lzio.h b/src/lzio.h
index 5f4b43de..5e73615c 100644
--- a/src/lzio.h
+++ b/src/lzio.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.h,v 1.7 2000/10/20 16:36:32 roberto Exp $
+** $Id: lzio.h,v 1.15 2003/03/20 16:00:56 roberto Exp $
 ** Buffered streams
 ** See Copyright Notice in lua.h
 */
@@ -8,46 +8,57 @@
 #ifndef lzio_h
 #define lzio_h
 
-#include <stdio.h>
+#include "lua.h"
 
 
-
-/* For Lua only */
-#define zFopen	luaZ_Fopen
-#define zsopen	luaZ_sopen
-#define zmopen	luaZ_mopen
-#define zread	luaZ_read
-
 #define EOZ	(-1)			/* end of stream */
 
-typedef struct zio ZIO;
+typedef struct Zio ZIO;
 
-ZIO* zFopen (ZIO* z, FILE* f, const char *name);	/* open FILEs */
-ZIO* zsopen (ZIO* z, const char* s, const char *name);	/* string */
-ZIO* zmopen (ZIO* z, const char* b, size_t size, const char *name); /* memory */
 
-size_t zread (ZIO* z, void* b, size_t n);	/* read next n bytes */
+#define char2int(c)	cast(int, cast(unsigned char, (c)))
+
+#define zgetc(z)  (((z)->n--)>0 ?  char2int(*(z)->p++) : luaZ_fill(z))
 
-#define zgetc(z)	(((z)->n--)>0 ? ((int)*(z)->p++): (z)->filbuf(z))
-#define zungetc(z)	(++(z)->n,--(z)->p)
 #define zname(z)	((z)->name)
 
+void luaZ_init (ZIO *z, lua_Chunkreader reader, void *data, const char *name);
+size_t luaZ_read (ZIO* z, void* b, size_t n);	/* read next n bytes */
+int luaZ_lookahead (ZIO *z);
 
 
-/* --------- Private Part ------------------ */
 
-#ifndef ZBSIZE
-#define ZBSIZE	256			/* buffer size */
-#endif
+typedef struct Mbuffer {
+  char *buffer;
+  size_t buffsize;
+} Mbuffer;
+
+
+char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n);
+
+#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0)
 
-struct zio {
-  size_t n;				/* bytes still unread */
-  const unsigned char* p;		/* current position in buffer */
-  int (*filbuf)(ZIO* z);
-  void* u;				/* additional data */
+#define luaZ_sizebuffer(buff)	((buff)->buffsize)
+#define luaZ_buffer(buff)	((buff)->buffer)
+
+#define luaZ_resizebuffer(L, buff, size) \
+	(luaM_reallocvector(L, (buff)->buffer, (buff)->buffsize, size, char), \
+	(buff)->buffsize = size)
+
+#define luaZ_freebuffer(L, buff)	luaZ_resizebuffer(L, buff, 0)
+
+
+/* --------- Private Part ------------------ */
+
+struct Zio {
+  size_t n;			/* bytes still unread */
+  const char *p;		/* current position in buffer */
+  lua_Chunkreader reader;
+  void* data;			/* additional data */
   const char *name;
-  unsigned char buffer[ZBSIZE];		/* buffer */
 };
 
 
+int luaZ_fill (ZIO *z);
+
 #endif
diff --git a/test/README b/test/README
index 6f410ee4..2a6601c5 100644
--- a/test/README
+++ b/test/README
@@ -1,6 +1,27 @@
 These are simple tests for Lua.  Some of them contain useful code.
-They are meant to be run to make sure Lua is ok and also to be read, to see
-how Lua programs can look like.
+They are meant to be run to make sure Lua is built correctly and also
+to be read, to see how Lua programs look.
+
+Here is a one-line summary of each program:
+
+   bisect.lua		bisection method for solving non-linear equations
+   cf.lua		temperature conversion table (celsius to farenheit)
+   echo.lua             echo command line arguments
+   env.lua              environment variables as automatic global variables
+   factorial.lua	factorial without recursion
+   fib.lua		fibonacci function with cache
+   fibfor.lua		fibonacci numbers with coroutines and generators
+   globals.lua		report global variable usage
+   hello.lua		the first program in every language
+   life.lua		Conway's Game of Life
+   luac.lua	 	bare-bones luac
+   printf.lua		an implementation of printf
+   readonly.lua		make global variables readonly
+   sieve.lua		the sieve of of Eratosthenes programmed with coroutines
+   sort.lua		two implementations of a sort function
+   table.lua		make table, grouping all data for the same item
+   trace-calls.lua	trace calls
+   trace-globals.lua	trace assigments to global variables
+   undefined.lua	catch "undefined" global variables
+   xd.lua		hex dump
 
-In the directory examples/, there is more useful code: a library for PostScript
-output and a database for a fake web site.
diff --git a/test/bisect.lua b/test/bisect.lua
index 9e1d8f70..f91e69bf 100644
--- a/test/bisect.lua
+++ b/test/bisect.lua
@@ -1,25 +1,23 @@
 -- bisection method for solving non-linear equations
 
+delta=1e-6	-- tolerance
+
 function bisect(f,a,b,fa,fb)
- write(n," a=",a," fa=",fa," b=",b," fb=",fb,"\n")
  local c=(a+b)/2
- if c==a or c==b then return c end
- if abs(a-b)<delta then return c end
+ io.write(n," c=",c," a=",a," b=",b,"\n")
+ if c==a or c==b or math.abs(a-b)<delta then return c,b-a end
  n=n+1
  local fc=f(c)
  if fa*fc<0 then return bisect(f,a,c,fa,fc) else return bisect(f,c,b,fc,fb) end
 end
 
--- find root of f in the inverval [a,b]. bisection needs that f(a)*f(b)<0
+-- find root of f in the inverval [a,b]. needs f(a)*f(b)<0
 function solve(f,a,b)
- delta=1e-9	-- tolerance
  n=0
- local z=bisect(f,a,b,f(a),f(b))
- write(format("after %d steps, root is %.10g, f=%g\n",n,z,f(z)))
+ local z,e=bisect(f,a,b,f(a),f(b))
+ io.write(string.format("after %d steps, root is %.17g with error %.1e, f=%.1e\n",n,z,e,f(z)))
 end
 
--- an example
-
 -- our function
 function f(x)
  return x*x*x-x-1
diff --git a/test/cf-for.lua b/test/cf-for.lua
deleted file mode 100644
index 1bd0ab27..00000000
--- a/test/cf-for.lua
+++ /dev/null
@@ -1,19 +0,0 @@
--- temperature conversion table
--- now using the new "for" statement
-
--- celsius to farenheit
-
-for c0=-20,50-1,10 do
-	write("C ")
-	for c=c0,c0+10-1 do
-		write(format("%3.0f ",c))
-	end
-	write("\n")
-	
-	write("F ")
-	for c=c0,c0+10-1 do
-		f=(9/5)*c+32
-		write(format("%3.0f ",f))
-	end
-	write("\n\n")
-end
diff --git a/test/cf.lua b/test/cf.lua
index 038b5e75..8cda54b9 100644
--- a/test/cf.lua
+++ b/test/cf.lua
@@ -1,27 +1,16 @@
--- temperature conversion table
+-- temperature conversion table (celsius to farenheit)
 
--- celsius to farenheit
-
-c0=-20
-while c0<50 do
-
-	c1=c0+10
-	write("C ")
-	c=c0
-	while c<c1 do
-		write(format("%3.0f ",c))
-		c=c+1
+for c0=-20,50-1,10 do
+	io.write("C ")
+	for c=c0,c0+10-1 do
+		io.write(string.format("%3.0f ",c))
 	end
-	write("\n")
+	io.write("\n")
 	
-	c=c0
-	write("F ")
-	while c<c1 do
+	io.write("F ")
+	for c=c0,c0+10-1 do
 		f=(9/5)*c+32
-		write(format("%3.0f ",f))
-		c=c+1
+		io.write(string.format("%3.0f ",f))
 	end
-	write("\n\n")
-
-	c0=c1
+	io.write("\n\n")
 end
diff --git a/test/compat.lua b/test/compat.lua
new file mode 100644
index 00000000..2a7f3731
--- /dev/null
+++ b/test/compat.lua
@@ -0,0 +1,192 @@
+-------------------------------------------------------------------
+-- Real globals
+-- _ALERT
+-- _ERRORMESSAGE
+-- _VERSION
+-- _G
+-- assert
+-- error
+-- metatable
+-- next
+-- print
+-- require
+-- tonumber
+-- tostring
+-- type
+-- unpack
+
+-------------------------------------------------------------------
+-- collectgarbage
+-- gcinfo
+
+-- globals
+
+-- call   -> protect(f, err)
+-- loadfile
+-- loadstring
+
+-- rawget
+-- rawset
+
+-- getargs = Main.getargs ??
+
+
+function do_ (f, err)
+  if not f then print(err); return end
+  local a,b = pcall(f)
+  if not a then print(b); return nil
+  else return b or true
+  end
+end
+
+function dostring(s) return do_(loadstring(s)) end
+-- function dofile(s) return do_(loadfile(s)) end
+
+-------------------------------------------------------------------
+-- Table library
+local tab = table
+foreach = tab.foreach
+foreachi = tab.foreachi
+getn = tab.getn
+tinsert = tab.insert
+tremove = tab.remove
+sort = tab.sort
+
+-------------------------------------------------------------------
+-- Debug library
+local dbg = debug
+getinfo = dbg.getinfo
+getlocal = dbg.getlocal
+setcallhook = function () error"`setcallhook' is deprecated" end
+setlinehook = function () error"`setlinehook' is deprecated" end
+setlocal = dbg.setlocal
+
+-------------------------------------------------------------------
+-- math library
+local math = math
+abs = math.abs
+acos = function (x) return math.deg(math.acos(x)) end
+asin = function (x) return math.deg(math.asin(x)) end
+atan = function (x) return math.deg(math.atan(x)) end
+atan2 = function (x,y) return math.deg(math.atan2(x,y)) end
+ceil = math.ceil
+cos = function (x) return math.cos(math.rad(x)) end
+deg = math.deg
+exp = math.exp
+floor = math.floor
+frexp = math.frexp
+ldexp = math.ldexp
+log = math.log
+log10 = math.log10
+max = math.max
+min = math.min
+mod = math.mod
+PI = math.pi
+--??? pow = math.pow  
+rad = math.rad
+random = math.random
+randomseed = math.randomseed
+sin = function (x) return math.sin(math.rad(x)) end
+sqrt = math.sqrt
+tan = function (x) return math.tan(math.rad(x)) end
+
+-------------------------------------------------------------------
+-- string library
+local str = string
+strbyte = str.byte
+strchar = str.char
+strfind = str.find
+format = str.format
+gsub = str.gsub
+strlen = str.len
+strlower = str.lower
+strrep = str.rep
+strsub = str.sub
+strupper = str.upper
+
+-------------------------------------------------------------------
+-- os library
+clock = os.clock
+date = os.date
+difftime = os.difftime
+execute = os.execute --?
+exit = os.exit
+getenv = os.getenv
+remove = os.remove
+rename = os.rename
+setlocale = os.setlocale
+time = os.time
+tmpname = os.tmpname
+
+-------------------------------------------------------------------
+-- compatibility only
+getglobal = function (n) return _G[n] end
+setglobal = function (n,v) _G[n] = v end
+
+-------------------------------------------------------------------
+
+local io, tab = io, table
+
+-- IO library (files)
+_STDIN = io.stdin
+_STDERR = io.stderr
+_STDOUT = io.stdout
+_INPUT = io.stdin
+_OUTPUT = io.stdout
+seek = io.stdin.seek   -- sick ;-)
+tmpfile = io.tmpfile
+closefile = io.close
+openfile = io.open
+
+function flush (f)
+  if f then f:flush()
+  else _OUTPUT:flush()
+  end
+end
+
+function readfrom (name)
+  if name == nil then
+    local f, err, cod = io.close(_INPUT)
+    _INPUT = io.stdin
+    return f, err, cod
+  else
+    local f, err, cod = io.open(name, "r")
+    _INPUT = f or _INPUT
+    return f, err, cod
+  end
+end
+
+function writeto (name)
+  if name == nil then
+    local f, err, cod = io.close(_OUTPUT)
+    _OUTPUT = io.stdout
+    return f, err, cod
+  else
+    local f, err, cod = io.open(name, "w")
+    _OUTPUT = f or _OUTPUT
+    return f, err, cod
+  end
+end
+
+function appendto (name)
+  local f, err, cod = io.open(name, "a")
+  _OUTPUT = f or _OUTPUT
+  return f, err, cod
+end
+
+function read (...)
+  local f = _INPUT
+  if type(arg[1]) == 'userdata' then
+    f = tab.remove(arg, 1)
+  end
+  return f:read(unpack(arg))
+end
+
+function write (...)
+  local f = _OUTPUT
+  if type(arg[1]) == 'userdata' then
+    f = tab.remove(arg, 1)
+  end
+  return f:write(unpack(arg))
+end
+
diff --git a/test/echo.lua b/test/echo.lua
new file mode 100644
index 00000000..4313439a
--- /dev/null
+++ b/test/echo.lua
@@ -0,0 +1,5 @@
+-- echo command line arguments
+
+for i=0,table.getn(arg) do
+ print(i,arg[i])
+end
diff --git a/test/env.lua b/test/env.lua
new file mode 100644
index 00000000..9e62a57f
--- /dev/null
+++ b/test/env.lua
@@ -0,0 +1,7 @@
+-- read environment variables as if they were global variables
+
+local f=function (t,i) return os.getenv(i) end
+setmetatable(getfenv(),{__index=f})
+
+-- an example
+print(a,USER,PATH)
diff --git a/test/examples/ps/hilbert.lua b/test/examples/ps/hilbert.lua
deleted file mode 100644
index dbcec963..00000000
--- a/test/examples/ps/hilbert.lua
+++ /dev/null
@@ -1,42 +0,0 @@
--- hilbert.c
--- Hilbert curve
--- Luiz Henrique de Figueiredo (lhf@csg.uwaterloo.ca)
--- 10 Nov 95
-
-dofile("ps.lua")
-
-function p()
- PS.lineto(x,y)
-end
-
-function a(n)
- if (n==0) then return else n=n-1 end
- d(n); y=y+h; p(); a(n); x=x+h; p(); a(n); y=y-h; p(); b(n);
-end
-
-function b(n)
- if (n==0) then return else n=n-1 end
- c(n); x=x-h; p(); b(n); y=y-h; p(); b(n); x=x+h; p(); a(n);
-end
-
-function c(n)
- if (n==0) then return else n=n-1 end
- b(n); y=y-h; p(); c(n); x=x-h; p(); c(n); y=y+h; p(); d(n);
-end
-
-function d(n)
- if (n==0) then return else n=n-1 end
- a(n); x=x+h; p(); d(n); y=y+h; p(); d(n); x=x-h; p(); c(n);
-end
-
-function hilbert(n)
- PS.open("hilbert curve")
- h=2^(9-n)
- x=0
- y=0
- PS.moveto(x,y)
- a(n)
- PS.close()
-end
-
-hilbert(5)
diff --git a/test/examples/ps/ps.lua b/test/examples/ps/ps.lua
deleted file mode 100644
index 0d749194..00000000
--- a/test/examples/ps/ps.lua
+++ /dev/null
@@ -1,181 +0,0 @@
--- ps.lua
--- lua interface to postscript
--- Luiz Henrique de Figueiredo (lhf@csg.uwaterloo.ca)
--- 14 May 96
-
-PS={}
-
-function P(x)
- write(x.."\n")
-end
-
--------------------------------------------------------------------- control --
-
-function PS.open(title)
- if title==nil then title="(no title)" end
- P("%!PS-Adobe-2.0 EPSF-1.2")
- P("%%Title: "..title)
- P("%%Creator: ps.lua from Lua 2.4")
- P("%%CreationDate: "..date())
- P("%%Pages: (atend)")
- P("%%BoundingBox: (atend)")
- P("%%EndComments")
- P("%%BeginProcSet: ps.lua")
- P("/s { stroke } bind def")
- P("/f { fill } bind def")
- P("/m { moveto } bind def")
- P("/l { lineto } bind def")
- P("/L { moveto lineto stroke } bind def")
- P("/t { show } bind def")
- P("/o { 0 360 arc stroke } bind def")
- P("/O { 0 360 arc fill } bind def")
- P("/p { 3 0 360 arc fil } bind def")
- P("/F { findfont exch scalefont setfont } bind def")
- P("/LS { 0 setdash } bind def")
- P("/LW { setlinewidth } bind def")
- P("%%EndProcSet: ps.lua")
- P("%%EndProlog")
- P("%%BeginSetup")
- P("0 setlinewidth")
- P("1 setlinejoin")
- P("1 setlinecap")
- P("10 /Times-Roman F")
- P("%%EndSetup\n")
- P("%%Page: 1 1")
--- cxmin=dv.xmin; cxmax=dv.xmax; cymin=dv.ymin; cymax=dv.ymax
- xmin=1000; xmax=-1000; ymin=1000; ymax=-1000
- page=1
-end
-
-function PS.close()
- P("stroke")
- P("showpage")
- P("%%Trailer")
- P("%%Pages: "..page)
- P("%%BoundingBox: "..xmin.." "..ymin.." "..xmax.." "..ymax)
- P("%%EOF")
-end
-
-function PS.clear()
- if (empty) then return end
- page=page+1
- P("showpage")
- P("%%Page: "..page.." "..page)
- empty=1
-end
-
-function PS.comment(s)
- P("% "..s)
-end
-
---------------------------------------------------------------- direct color --
-
-function PS.rgbcolor(r,g,b)
- P(r.." "..g.." "..b.." setrgbcolor")
-end
-
-function PS.gray(g)
- P(g.." setgray")
-end
-
----------------------------------------------------------------- named color --
-
-function PS.color(c)
- P("C"..c)
-end
-
-function PS.defrgbcolor(c,r,g,b)
- P("/C"..c.." { "..r.." "..g.." "..b.." setrgbcolor } def")
-end
-
-function PS.defgraycolor(c,g)
- P("/C"..c.." { "..g.." setgray } def")
-end
-
------------------------------------------------------------------------ line --
-
-function PS.line(x1,y1,x2,y2)
- P(x2.." "..y2.." "..x1.." "..y1.." L")
- PS.update(x1,y1)
- PS.update(x2,y2)
-end
-
-function PS.moveto(x,y)
- P(x.." "..y.." m")
- PS.update(x,y)
-end
-
-function PS.lineto(x,y)
- P(x.." "..y.." l")
- PS.update(x,y)
-end
-
-function PS.linewidth(w)
- P(w.." LW")
-end
-
-function PS.linestyle(s)
- P("["..s.."] LS")
-end
-
------------------------------------------------------------------------ text --
-
-function PS.font(name,size)
- if (size==nil) then size=10 end
- P(size.." /"..name.." F")
-end
-
-function PS.text(x,y,s)
- P(x.." "..y.."m ("..s..") t")
- PS.update(x,y)
-end
-
---------------------------------------------------------------------- circle --
-
-function PS.circle(x,y,r)
- P(x.." "..y.." "..r.." o")
- PS.update(x-r,y-r)
- PS.update(x+r,y+r)
-end
-
-function PS.disk(x,y,r)
- P(x.." "..y.." "..r.." O")
- PS.update(x-r,y-r)
- PS.update(x+r,y+r)
-end
-
-function PS.dot(x,y)
- P(x.." "..y.." p")
- PS.update(x-r,y-r)
- PS.update(x+r,y+r)
-end
-
------------------------------------------------------------------------- box --
-
-function PS.rectangle(xmin,xmax,ymin,ymax)
- P(xmin.." "..ymin.." m "..
-   xmax.." "..ymin.." l "..
-   xmax.." "..ymax.." l "..
-   xmin.." "..ymax.." l s")
- PS.update(xmin,ymin)
- PS.update(xmax,ymax)
-end
-
-function PS.box(xmin,xmax,ymin,ymax)
- P(xmin.." "..ymin.." m "..
-   xmax.." "..ymin.." l "..
-   xmax.." "..ymax.." l "..
-   xmin.." "..ymax.." l f")
- PS.update(xmin,ymin)
- PS.update(xmax,ymax)
-end
-
--------------------------------------------------------- update bounding box --
-
-function PS.update(x,y)
--- if (x>=cxmin and x<=cxmax and y>=cxmin and y<=cxmax) then
-  if (x<xmin) then xmin=x elseif (x>xmax) then xmax=x end
-  if (y<ymin) then ymin=y elseif (y>ymax) then ymax=y end
-  empty=0
--- end
-end
diff --git a/test/examples/www/README b/test/examples/www/README
deleted file mode 100644
index b0e1e8bd..00000000
--- a/test/examples/www/README
+++ /dev/null
@@ -1,10 +0,0 @@
-This directory contains a database for a fake web site.
-Standard web page for the persons listed in db.lua are created
-automatically from template.html with staff.lua.
-(See http://www.cos.ufrj.br for a real web site created in this way.)
-
-To run, type lua db.lua.
-
-This example is meant to show the power of gsub and Lua declarative constructs,
-which have been combined here into a "mail-merge" application.
-
diff --git a/test/examples/www/db.lua b/test/examples/www/db.lua
deleted file mode 100644
index 53d78024..00000000
--- a/test/examples/www/db.lua
+++ /dev/null
@@ -1,46 +0,0 @@
-dofile("staff.lua")
-
-global{
-  ROOT='http://www.tecgraf.puc-rio.br',
-  EMAIL="|LOGIN|@tecgraf.puc-rio.br",
-  WWW="|ROOT|/~|LOGIN|",
-  webmast='|ROOT|/webmaster.html',
-  TECGRAF='<A HREF="http://www.tecgraf.puc-rio.br">TeCGraf</A>',
-  CS='<A HREF="http://www.inf.puc-rio.br">Computer Science Department</A>',
-  PUCRIO='<A HREF="http://www.puc-rio.br">PUC-Rio</A>',
-}
-
-staff{
-DI="inf.puc-rio.br",
-  LOGIN="roberto",
-  NAME="Roberto Ierusalimschy",
-  TITLE="D.Sc., |PUCRIO|, 1990",
-  POSITION="Associate Professor, |CS|, |PUCRIO|",
-  AREAS="Programming Languages, Object Oriented Programming",
-  EMAIL="|LOGIN|@|DI|",
-  WWW="http://www.|DI|/~|LOGIN|",
-}
-
-staff{
-PCG="http://www.graphics.cornell.edu",
-  LOGIN="celes",
-  NAME="Waldemar Celes",
-  TITLE="D.Sc., |PUCRIO|, 1995",
-  POSITION="Postdoctoral Associate at "..
-'<A HREF="|PCG|">Program of Computer Graphics</A>, '..
-'<A HREF="http://www.cornell.edu">Cornell University</A>',
-  WWW="|PCG|/~celes/",
-  AREAS="Image segmentation and 3D reconstruction; "
-.."Physical simulation and educational software;"
-.."Geometric modeling and topological data structures;"
-.."Extension languages and customizable applications"
-}
-
-staff{
-  LOGIN="lhf",
-  NAME="Luiz Henrique de Figueiredo",
-  TITLE='D.Sc., <A HREF="http://www.impa.br">IMPA</A>, 1992',
-  POSITION='Associate Researcher at <A HREF="http://www.lncc.br">LNCC</A>; Consultant at |TECGRAF|',
-  AREAS="Geometric modeling; Software tools",
-  WWW="http://www2.lncc.br/~lhf/",
-}
diff --git a/test/examples/www/staff.lua b/test/examples/www/staff.lua
deleted file mode 100644
index f36df4ad..00000000
--- a/test/examples/www/staff.lua
+++ /dev/null
@@ -1,33 +0,0 @@
-readfrom("template.html")
-TEMPLATE=read("*a")
-readfrom()
-
-PAT="|(%a%a*)|"
-
-GLOBAL={
-	DATE=date("%d/%m/%Y %T"),
-}
-
-function get(i)
-     if  LOCAL[i] then return  LOCAL[i]
- elseif GLOBAL[i] then return GLOBAL[i]
- else return "<BLINK>?"..i.."?</BLINK>" end
-end
-
-function global(t)
- for i,v in t do
-  GLOBAL[i]=v
- end
-end
-
-function staff(t)
- LOCAL=t
- if t.AREAS then t.AREAS=gsub(t.AREAS,"[;,] *","\n<LI>") end
- local p,n=TEMPLATE
- if t.WWW=="" then p=gsub(p,'<A HREF="|WWW|">|NAME|</A>',"|NAME|") end
- repeat p,n=gsub(p,PAT,get) until n==0
- write(t.LOGIN,"\n")
- writeto(t.LOGIN..".html")
- write(p)
- writeto()
-end
diff --git a/test/examples/www/template.html b/test/examples/www/template.html
deleted file mode 100644
index c8494b76..00000000
--- a/test/examples/www/template.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<HTML>
-<HEAD>
-<TITLE>
-Imaginary web site:Staff:|LOGIN|
-</TITLE>
-</HEAD>
-
-<BODY>
-<H1><A HREF="|WWW|">|NAME|</A></H1>
-<A HREF="mailto:|EMAIL|">|EMAIL|</A>
-<P>
-
-|POSITION|<BR>
-|TITLE|<P>
-
-<H2>Research areas</H2>
-<UL>
-<LI>|AREAS|
-</UL>
-<P>
-
-<HR>
-Last update in |DATE| by
-<A HREF="|webmast|">websmaster</A>.
-<P>
-
-</BODY>
-
-</HTML>
diff --git a/test/factorial.lua b/test/factorial.lua
index d9cc375c..7c4cf0fa 100644
--- a/test/factorial.lua
+++ b/test/factorial.lua
@@ -1,12 +1,11 @@
 -- function closures are powerful
 
 -- traditional fixed-point operator from functional programming
-
 Y = function (g)
       local a = function (f) return f(f) end
       return a(function (f)
-                 return %g(function (x)
-                             local c=%f(%f)
+                 return g(function (x)
+                             local c=f(f)
                              return c(x)
                            end)
                end)
@@ -14,24 +13,20 @@ end
 
 
 -- factorial without recursion
-
 F = function (f)
       return function (n)
                if n == 0 then return 1
-               else return n*%f(n-1) end
+               else return n*f(n-1) end
              end
     end
 
 factorial = Y(F)   -- factorial is the fixed point of F
 
 -- now test it
-
 function test(x)
-	write(x,"! = ",factorial(x),"\n")
+	io.write(x,"! = ",factorial(x),"\n")
 end
 
-test(3)
-test(4)
-test(5)
-test(6)
-test(7)
+for n=0,16 do
+	test(n)
+end
diff --git a/test/fib.lua b/test/fib.lua
index d946946a..97a921b1 100644
--- a/test/fib.lua
+++ b/test/fib.lua
@@ -1,5 +1,6 @@
--- very inefficient fibonacci function
+-- fibonacci function with cache
 
+-- very inefficient fibonacci function
 function fib(n)
 	N=N+1
 	if n<2 then
@@ -9,31 +10,31 @@ function fib(n)
 	end
 end
 
--- a much faster cached version
-
+-- a general-purpose value cache
 function cache(f)
 	local c={}
 	return function (x)
-		local y=%c[x]
+		local y=c[x]
 		if not y then
-			y=%f(x)
-			%c[x]=y
+			y=f(x)
+			c[x]=y
 		end
 		return y
 	end
 end
 
-function test(s)
+-- run and time it
+function test(s,f)
 	N=0
-	local c=clock()
-	local v=fib(n)
-	local t=clock()-c
+	local c=os.clock()
+	local v=f(n)
+	local t=os.clock()-c
 	print(s,n,v,t,N)
 end
 
-n=n or 24		-- for other values, do lua -e n=XX fib.lua
+n=arg[1] or 24		-- for other values, do lua fib.lua XX
 n=tonumber(n)
 print("","n","value","time","evals")
-test("plain")
+test("plain",fib)
 fib=cache(fib)
-test("cached")
+test("cached",fib)
diff --git a/test/fibfor.lua b/test/fibfor.lua
new file mode 100644
index 00000000..19bb34b4
--- /dev/null
+++ b/test/fibfor.lua
@@ -0,0 +1,13 @@
+-- example of for with generator functions
+
+function generatefib (n)
+  return coroutine.wrap(function ()
+    local a,b = 1, 1
+    while a <= n do
+      coroutine.yield(a)
+      a, b = b, a+b
+    end
+  end, n)
+end
+
+for i in generatefib(1000) do print(i) end
diff --git a/test/globals.lua b/test/globals.lua
index baa75049..d4c20e15 100644
--- a/test/globals.lua
+++ b/test/globals.lua
@@ -1,19 +1,13 @@
--- reads the output of luac -d -l -p and reports global variable usage
+-- reads luac listings and reports global variable usage
 -- lines where a global is written to are marked with "*"
--- typical usage: luac -p -l file.lua | lua globals.lua | sort
-
-local P="^.*; "		-- pattern to extract comments
+-- typical usage: luac -p -l file.lua | lua globals.lua | sort | lua table.lua
 
 while 1 do
-	local s=read()
-	if s==nil then return end
-	if strfind(s,"%sGETGLOBAL") then
-		local g=gsub(s,P,"")
-		local _,_,l=strfind(s,"(%d+)")
-		write(g,"\t",l,"\n")
-	elseif strfind(s,"%sSETGLOBAL") then
-		local g=gsub(s,P,"")
-		local _,_,l=strfind(s,"(%d+)")
-		write(g,"\t",l,"*\n")
-	end
+ local s=io.read()
+ if s==nil then break end
+ local ok,_,l,op,g=string.find(s,"%[%-?(%d*)%]%s*([GS])ETGLOBAL.-;%s+(.*)$")
+ if ok then
+  if op=="S" then op="*" else op="" end
+  io.write(g,"\t",l,op,"\n")
+ end
 end
diff --git a/test/hello.lua b/test/hello.lua
index ea818b9a..0925498f 100644
--- a/test/hello.lua
+++ b/test/hello.lua
@@ -1,3 +1,3 @@
 -- the first program in every language
 
-write("hello world, from Lua!\n")
+io.write("Hello world, from ",_VERSION,"!\n")
diff --git a/test/life.lua b/test/life.lua
index 7c817a04..911d9fe1 100644
--- a/test/life.lua
+++ b/test/life.lua
@@ -1,28 +1,25 @@
 -- life.lua
 -- original by Dave Bollinger <DBollinger@compuserve.com> posted to lua-l
 -- modified to use ANSI terminal escape sequences
+-- modified to use for instead of while
 
-ALIVE="O"
-DEAD="-"
+local write=io.write
+
+ALIVE="¥"	DEAD="þ"
+ALIVE="O"	DEAD="-"
 
 function delay() -- NOTE: SYSTEM-DEPENDENT, adjust as necessary
-  local i=10000
-  while i>0 do i=i-1 end
-  -- local i=clock()+1 while(clock()<i) do end
+  for i=1,10000 do end
+  -- local i=os.clock()+1 while(os.clock()<i) do end
 end
 
 function ARRAY2D(w,h)
-  local t = {}
-  t.w=w
-  t.h=h
-  while h>0 do
-    t[h] = {}
-    local x=w
-    while x>0 do
-      t[h][x]=0
-      x=x-1
+  local t = {w=w,h=h}
+  for y=1,h do
+    t[y] = {}
+    for x=1,w do
+      t[y][x]=0
     end
-    h=h-1
   end
   return t
 end
@@ -31,14 +28,10 @@ _CELLS = {}
 
 -- give birth to a "shape" within the cell array
 function _CELLS:spawn(shape,left,top)
-  local y=0
-  while y<shape.h do
-    local x=0
-    while x<shape.w do
+  for y=0,shape.h-1 do
+    for x=0,shape.w-1 do
       self[top+y][left+x] = shape[y*shape.w+x+1]
-      x=x+1
     end
-    y=y+1
   end
 end
 
@@ -61,15 +54,11 @@ end
 -- output the array to screen
 function _CELLS:draw()
   local out="" -- accumulate to reduce flicker
-  local y=1
-  while y <= self.h do
-    local x=1
-    while x <= self.w do
+  for y=1,self.h do
+   for x=1,self.w do
       out=out..(((self[y][x]>0) and ALIVE) or DEAD)
-      x=x+1
     end
     out=out.."\n"
-    y=y+1
   end
   write(out)
 end
@@ -112,8 +101,9 @@ function LIFE(w,h)
     thisgen,nextgen = nextgen,thisgen
     write("\027[H")	-- ANSI home cursor
     thisgen:draw()
-    write("Generation: "..gen.."\n")
+    write("Life - generation ",gen,"\n")
     gen=gen+1
+    if gen>2000 then break end
     --delay()		-- no delay
   end
 end
diff --git a/test/lisp.lua b/test/lisp.lua
deleted file mode 100644
index e6bcd084..00000000
--- a/test/lisp.lua
+++ /dev/null
@@ -1,22 +0,0 @@
--- a simple LISP evaluator
-
-function eval(x)
-	if type(x)=="table" then
-		return eval(x[1])(eval(x[2]),eval(x[3]))
-	else
-		return x
-	end
-end
-
-function add(x,y) return x+y end
-function sub(x,y) return x-y end
-function mul(x,y) return x*y end
-function div(x,y) return x/y end
-function pow(x,y) return x^y end
-
--- an example
-
-function E(x) print(eval(x)) end
-
-E{add,1,{mul,2,3}}
-E{sin,60}
diff --git a/test/luac.lua b/test/luac.lua
new file mode 100644
index 00000000..f9aa9052
--- /dev/null
+++ b/test/luac.lua
@@ -0,0 +1,7 @@
+-- bare-bones luac in Lua
+-- usage: lua luac.lua file.lua
+
+assert(arg[1]~=nil,"usage: lua luac.lua file.lua")
+f=assert(io.open("luac.out","w"))
+f:write(string.dump(loadfile(arg[1])))
+io.close(f)
diff --git a/test/old.lua b/test/old.lua
deleted file mode 100644
index ebb4e70b..00000000
--- a/test/old.lua
+++ /dev/null
@@ -1,42 +0,0 @@
--- implementation of old functions
-
-function foreach(t,f)
- for i,v in t do
-  local r=f(i,v)
-  if r then return r end
- end
-end
-
-function foreachi(t,f)
- for i=1,getn(t) do
-  local r=f(i,t[i])
-  if r then return r end
- end
-end
-
-function foreachvar(f)
- return foreach(globals(),f)
-end
-
-function nextvar(n)
- return next(globals(),n)
-end
-
-function rawgetglobal(n)
- return rawget(globals(),n)
-end
-
-function rawsetglobal(n,v)
- return rawset(globals(),n,v)
-end
-
-rawsettable=rawset
-rawgettable=rawget
-
-function getglobal(n)
- return globals()[n]
-end
-
-function setglobal(n,v)
- globals()[n]=v
-end
diff --git a/test/printf.lua b/test/printf.lua
new file mode 100644
index 00000000..66dfda65
--- /dev/null
+++ b/test/printf.lua
@@ -0,0 +1,7 @@
+-- an implementation of printf
+
+function printf(...)
+ io.write(string.format(unpack(arg)))
+end
+
+printf("Hello %s from %s on %s\n",os.getenv"USER" or "there",_VERSION,os.date())
diff --git a/test/qp.lua b/test/qp.lua
deleted file mode 100644
index eb6b3205..00000000
--- a/test/qp.lua
+++ /dev/null
@@ -1,6 +0,0 @@
--- decode quoted-printable text
-
-T=read"*a"
-T=gsub(T,"=\n","")
-T=gsub(T,"=(%x%x)",function (x) return strchar(tonumber(x,16)) end)
-write(T)
diff --git a/test/readonly.lua b/test/readonly.lua
new file mode 100644
index 00000000..85c0b4e0
--- /dev/null
+++ b/test/readonly.lua
@@ -0,0 +1,12 @@
+-- make global variables readonly
+
+local f=function (t,i) error("cannot redefine global variable `"..i.."'",2) end
+local g={}
+local G=getfenv()
+setmetatable(g,{__index=G,__newindex=f})
+setfenv(1,g)
+
+-- an example
+rawset(g,"x",3)
+x=2
+y=1	-- cannot redefine `y'
diff --git a/test/save.lua b/test/save.lua
deleted file mode 100644
index 855e4c19..00000000
--- a/test/save.lua
+++ /dev/null
@@ -1,42 +0,0 @@
--- dump global environment
-
-function savevar (n,v)
- if v == nil then return end
- if type(v)=="userdata" or type(v)=="function" then return end
- -- if type(v)=="userdata" or type(v)=="function" then write("\t-- ") end
- write(n,"=")
- if type(v) == "string" then write(format("%q",v))
- elseif type(v) == "table" then
-   if v.__visited__ ~= nil then
-     write(v.__visited__)
-   else
-    write("{}\n")
-    v.__visited__ = n
-    for r,f in v do
-      if r ~= "__visited__" then
-        if type(r) == 'string' then
-          savevar(n.."."..r,f)
-	else
-          savevar(n.."["..r.."]",f)
-	end
-      end
-    end
-   end
- else write(tostring(v)) end
- write("\n")
-end
-
-function save ()
- write("\n-- global environment\n")
- foreach(globals(),savevar)
-end
-
--- an example
-
-a = 3
-x = {a = 4, b = "name", l={4,5,67}}
-
-b = {t=5}
-x.next = b
-
-save()
diff --git a/test/sieve.lua b/test/sieve.lua
new file mode 100644
index 00000000..0871bb21
--- /dev/null
+++ b/test/sieve.lua
@@ -0,0 +1,29 @@
+-- the sieve of of Eratosthenes programmed with coroutines
+-- typical usage: lua -e N=1000 sieve.lua | column
+
+-- generate all the numbers from 2 to n
+function gen (n)
+  return coroutine.wrap(function ()
+    for i=2,n do coroutine.yield(i) end
+  end)
+end
+
+-- filter the numbers generated by `g', removing multiples of `p'
+function filter (p, g)
+  return coroutine.wrap(function ()
+    while 1 do
+      local n = g()
+      if n == nil then return end
+      if math.mod(n, p) ~= 0 then coroutine.yield(n) end
+    end
+  end)
+end
+
+N=N or 1000		-- from command line
+x = gen(N)		-- generate primes up to N
+while 1 do
+  local n = x()		-- pick a number until done
+  if n == nil then break end
+  print(n)		-- must be a prime number
+  x = filter(n, x)	-- now remove its multiples
+end
diff --git a/test/sort.lua b/test/sort.lua
index 1d50ad47..0bcb15f8 100644
--- a/test/sort.lua
+++ b/test/sort.lua
@@ -4,7 +4,7 @@
 -- extracted from Programming Pearls, page 110
 function qsort(x,l,u,f)
  if l<u then
-  local m=random(u-(l-1))+l-1		-- choose a random pivot in range l..u
+  local m=math.random(u-(l-1))+l-1	-- choose a random pivot in range l..u
   x[l],x[m]=x[m],x[l]			-- swap pivot to first position
   local t=x[l]				-- pivot value
   m=l
@@ -38,14 +38,14 @@ function selectionsort(x,n,f)
 end
 
 function show(m,x)
- write(m,"\n\t")
+ io.write(m,"\n\t")
  local i=1
  while x[i] do
-  write(x[i])
+  io.write(x[i])
   i=i+1
-  if x[i] then write(",") end
+  if x[i] then io.write(",") end
  end
- write("\n")
+ io.write("\n")
 end
 
 function testsorts(x)
diff --git a/test/table.lua b/test/table.lua
index 2c2dd90a..bc2cd60c 100644
--- a/test/table.lua
+++ b/test/table.lua
@@ -1,7 +1,12 @@
+-- make table, grouping all data for the same item
+-- input is 2 columns (item, data)
+
 local A
 while 1 do
- local a,b=read("*w","*w")
- if a==nil then break end
- if a~=A then A=a write("\n",a,":\n") end
- write(b," ")
+ local l=io.read()
+ if l==nil then break end
+ local _,_,a,b=string.find(l,'"?(%w+)"?%s*(.*)$')
+ if a~=A then A=a io.write("\n",a,":") end
+ io.write(" ",b)
 end
+io.write("\n")
diff --git a/test/trace-calls.lua b/test/trace-calls.lua
index a073cc20..63c8b8f3 100644
--- a/test/trace-calls.lua
+++ b/test/trace-calls.lua
@@ -1,23 +1,32 @@
 -- trace calls
--- example: lua trace-calls.lua hello.lua bisect.lua
+-- example: lua -ltrace-calls.lua bisect.lua
 
-function callhook(func)
- local t=getinfo(2)
- write(">>> ")
---foreach(t,print)
+local level=0
+
+function hook(event)
+ local t=debug.getinfo(3)
+ io.write(level," >>> ",string.rep(" ",level))
+ if t~=nil and t.currentline>=0 then io.write(t.short_src,":",t.currentline," ") end
+ t=debug.getinfo(2)
+ if event=="call" then
+  level=level+1
+ else
+  level=level-1 if level<0 then level=0 end
+ end
  if t.what=="main" then
-  if func=="call" then
-   write("begin ",t.source)
+  if event=="call" then
+   io.write("begin ",t.short_src)
   else
-   write("end ",t.source)
+   io.write("end ",t.short_src)
   end
  elseif t.what=="Lua" then
-  write(func," ",t.name," <",t.linedefined,":",t.source,">")
+-- table.foreach(t,print)
+  io.write(event," ",t.name or "(Lua)"," <",t.linedefined,":",t.short_src,">")
  else
-  write(func," ",t.name," [",t.what,"] ")
+ io.write(event," ",t.name or "(C)"," [",t.what,"] ")
  end
- if t.currentline>=0 then write(":",t.currentline) end
- write("\n")
+ io.write("\n")
 end
 
-setcallhook(callhook)
+debug.sethook(hook,"cr")
+level=0
diff --git a/test/trace-globals.lua b/test/trace-globals.lua
index 566e1106..295e670c 100644
--- a/test/trace-globals.lua
+++ b/test/trace-globals.lua
@@ -1,75 +1,38 @@
--- shows how to trace assigments to global variables
-
--- a tostring that quotes strings. note the use of the original tostring.
-local tostring=function(a)
- if tag(a)==tag("") then
-  return format("%q",a)
- else
-  return %tostring(a)
+-- trace assigments to global variables
+
+do
+ -- a tostring that quotes strings. note the use of the original tostring.
+ local _tostring=tostring
+ local tostring=function(a)
+  if type(a)=="string" then
+   return string.format("%q",a)
+  else
+   return _tostring(a)
+  end
  end
-end
-
-local T=newtag()
-
-local Tlog=function (name,old,new)
- local t=getinfo(3,"Sl")
- local line=t.currentline
- write(t.source)
- if line>=0 then write(":",line) end
- write(" -- ",name," is now ",%tostring(new)," (was ",%tostring(old),")","\n")
-end
-
-local Tgetnew=function (name)
- local t=settag({},%T)
- rawset(globals(),name,t)
- return nil
-end
-
-local Tsetnew=function (name,old,new)
- %Tlog(name,old,new)
- local t=settag({value=new},%T)
- rawset(globals(),name,t)
- return t
-end
 
-local Tsetglobal=function (name,old,new)
- %Tlog(name,old.value,new)
- old.value=new 
-end
-
-local Tgetglobal=function (x,value)
- return value.value
-end
-
-settagmethod(T,"getglobal",Tgetglobal)
-settagmethod(T,"setglobal",Tsetglobal)
-
--- to trace only selected variables, use the following function
--- and comment the next two calls to settagmethod
+ local log=function (name,old,new)
+  local t=debug.getinfo(3,"Sl")
+  local line=t.currentline
+  io.write(t.short_src)
+  if line>=0 then io.write(":",line) end
+  io.write(": ",name," is now ",tostring(new)," (was ",tostring(old),")","\n")
+ end
 
-function trace(name)
- local t=settag({value=rawget(globals(),name)},%T)
- rawset(globals(),name,t)
+ local g={}
+ local set=function (t,name,value)
+  log(name,g[name],value)
+  g[name]=value
+ end
+ setmetatable(getfenv(),{__index=g,__newindex=set})
 end
- 
-settagmethod(tag(nil),"getglobal",Tgetnew)
-settagmethod(tag(nil),"setglobal",Tsetnew)
 
 -- an example
 
-trace"a"
-print(a)
 a=1
 b=2
-c=3
 a=10
 b=20
-c=30
-trace"b"
-b="lua"
-c={}
-a=print
-c=nil
-c=100
-
-print(a,b,c,d)
+b=nil
+b=200
+print(a,b,c)
diff --git a/test/undefined.lua b/test/undefined.lua
index bbecffe3..efe5f245 100644
--- a/test/undefined.lua
+++ b/test/undefined.lua
@@ -1,20 +1,9 @@
--- catch "undefined" global variables. see FAQ.
+-- catch "undefined" global variables
 
-do
- local f=function(name)
-  local v=rawget(globals(),name)
-  if v then
-   return v
-  else
-   error("undefined global variable `"..name.."'")
-  end
- end
-
- settagmethod(tag(nil),"getglobal",f)
-end
+local f=function (t,i) error("undefined global variable `"..i.."'",2) end
+setmetatable(getfenv(),{__index=f})
 
 -- an example
-
 a=1
 c=3
-print(a,b,c)	-- 'b' is undefined
+print(a,b,c)	-- `b' is undefined
diff --git a/test/webform.lua b/test/webform.lua
deleted file mode 100644
index 3e4c3ce4..00000000
--- a/test/webform.lua
+++ /dev/null
@@ -1,8 +0,0 @@
--- convert POST data to Lua table
-
-T=read"*a"	-- for GET, use T=getenv"QUERY_STRING"
-T=gsub(T,"=","=[[")
-T=gsub(T,"&","]],\n")
-T=gsub(T,"+"," ")
-T=gsub(T,"%%(%x%x)",function (x) return strchar(tonumber(x,16)) end)
-write("form{\n",T,"]]}\n")
diff --git a/test/xd.lua b/test/xd.lua
new file mode 100644
index 00000000..32331dc1
--- /dev/null
+++ b/test/xd.lua
@@ -0,0 +1,14 @@
+-- hex dump
+-- usage: lua xd.lua < file
+
+local offset=0
+
+while 1 do
+ local s=io.read(16)
+ if s==nil then return end
+ io.write(string.format("%08X  ",offset))
+ string.gsub(s,"(.)",function (c) io.write(string.format("%02X ",string.byte(c))) end)
+ io.write(string.rep(" ",3*(16-string.len(s))))
+ io.write(" ",string.gsub(s,"%c","."),"\n") 
+ offset=offset+16
+end