[inseperable changes from patch from perl-5.003_95 to perl-5.003_86]

[editor's note: this commit was prepared manually so may differ in
minor ways to other inseperable changes commits]

 CORE LANGUAGE CHANGES

  Title:  "Support $ENV{PERL5OPT}"
   From:  Chip Salzenberg
  Files:  perl.c pod/perldiag.pod pod/perldelta.pod pod/perlrun.pod

  Title:  "Implement void context, in which C<wantarray> is undef"
   From:  Chip Salzenberg
  Files:  cop.h doop.c dump.c global.sym gv.c op.c op.h perl.c
          pod/perlcall.pod pod/perldelta.pod pod/perlfunc.pod
          pod/perlguts.pod pod/perlsub.pod pp.c pp_ctl.c pp_hot.c
          pp_sys.c proto.h

  Title:  "Don't look up &AUTOLOAD in @ISA when calling plain function"
   From:  Chip Salzenberg
  Files:  global.sym gv.c lib/Text/ParseWords.pm pod/perldelta.pod
          pp_hot.c proto.h t/op/method.t

  Title:  "Allow closures to be constant subroutines"
   From:  Chip Salzenberg
  Files:  op.c

  Title:  "Make C<scalar(reverse)> mean C<scalar(reverse $_)>"
   From:  Chip Salzenberg
  Files:  pp.c

  Title:  "Fix lexical suicide from C<my $x = $x> in sub"
   From:  Chip Salzenberg
  Files:  op.c

  Title:  "Make "Unrecog. char." fatal, and update its doc"
   From:  Chip Salzenberg
  Files:  pod/perldiag.pod toke.c

 CORE PORTABILITY

  Title:  "safefree() mismatch"
   From:  Roderick Schertler
 Msg-ID:  <21338.859653381@eeyore.ibcinc.com>
   Date:  Sat, 29 Mar 1997 11:36:21 -0500
  Files:  util.c

    (applied based on p5p patch as commit id 9b9b466fb02dc96c81439bafbb3b2da55238cfd2)

  Title:  "Win32 update (seven patches)"
   From:  Gurusamy Sarathy and Nick Ing-Simmons
  Files:  EXTERN.h MANIFEST win32/Makefile win32/perl.mak
          win32/perl.rc win32/perldll.mak win32/makedef.pl
          win32/modules.mak win32/win32io.c win32/bin/pl2bat.bat

 OTHER CORE CHANGES

  Title:  "Report PERL* environment variables in -V and perlbug"
   From:  Chip Salzenberg
  Files:  perl.c utils/perlbug.PL

  Title:  "Typo in perl.c: Printing NO_EMBED for perl -V"
   From:  Gisle Aas
 Msg-ID:  <199703301922.VAA13509@furubotn.sn.no>
   Date:  Sun, 30 Mar 1997 21:22:11 +0200
  Files:  perl.c

    (applied based on p5p patch as commit id b6c639e4b1912ad03b9b10ba9518d96bd0a6cfaf)

  Title:  "Don't let C<$var = $var> untaint $var"
   From:  Chip Salzenberg
  Files:  pp_hot.c pp_sys.c sv.h t/op/taint.t

  Title:  "Fix autoviv bug in C<my $x; ++$x->{KEY}>"
   From:  Chip Salzenberg
  Files:  pp_hot.c

  Title:  "Re: 5.004's new srand() default seed"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703302219.AAA20998@bombur2.uio.no>
   Date:  Mon, 31 Mar 1997 00:19:13 +0200 (MET DST)
  Files:  pp.c

    (applied based on p5p patch as commit id d7d933a26349f945f93b2f0dbf85b773d8ca3219)

  Title:  "Re: embedded perl and top_env problem "
   From:  Gurusamy Sarathy
 Msg-ID:  <199703280031.TAA05711@aatma.engin.umich.edu>
   Date:  Thu, 27 Mar 1997 19:31:42 -0500
  Files:  gv.c interp.sym perl.c perl.h pp_ctl.c pp_sys.c scope.h util.c

    (applied based on p5p patch as commit id f289f7d2518e7a8a82114282e774adf50fa6ce85)

  Title:  "Define and use new macro: boolSV()"
   From:  Tim Bunce
  Files:  gv.c lib/ExtUtils/typemap os2/os2.c pp.c pp_hot.c pp_sys.c
          sv.c sv.h universal.c vms/vms.c

  Title:  "Re: strict @F"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703252110.WAA16038@bombur2.uio.no>
   Date:  Tue, 25 Mar 1997 22:10:33 +0100 (MET)
  Files:  toke.c

    (applied based on p5p patch as commit id dfd44a5c8c8dd4c001c595debfe73d011a96d844)

  Title:  "Try harder to identify errors at EOF"
   From:  Chip Salzenberg
  Files:  toke.c

  Title:  "Minor string change in toke.c: 'bareword'"
   From:  lvirden@cas.org
 Msg-ID:  <1997Mar27.130247.1911552@hmivax.humgen.upenn.edu>
   Date:  Thu, 27 Mar 1997 13:02:46 -0500 (EST)
  Files:  toke.c

    (applied based on p5p patch as commit id 9b56c8f8085a9e773ad87c6b3c1d0b5e39dbc348)

  Title:  "Improve diagnostic on \r in program text"
   From:  Chip Salzenberg
  Files:  pod/perldiag.pod toke.c

  Title:  "Make Sock_size_t typedef work right"
   From:  Chip Salzenberg
  Files:  perl.h pp_sys.c

 LIBRARY AND EXTENSIONS

  Title:  "New module constant.pm"
   From:  Tom Phoenix
  Files:  MANIFEST lib/constant.pm op.c pp.c t/pragma/constant.t

  Title:  "Remove chat2"
   From:  Chip Salzenberg
  Files:  MANIFEST lib/chat2.inter lib/chat2.pl

  Title:  "Include CGI.pm 2.32"
   From:  Chip Salzenberg
  Files:  MANIFEST eg/cgi/* lib/CGI.pm lib/CGI/Apache.pm
          lib/CGI/Carp.pm lib/CGI/Fast.pm lib/CGI/Push.pm
          lib/CGI/Switch.pm

 UTILITIES

  Title:  "Tom C's Pod::Html and html tools, as of 30 March 97"
   From:  Chip Salzenberg
  Files:  MANIFEST installhtml lib/Pod/Html.pm pod/pod2html.PL

  Title:  "Fix path bugs in installhtml"
   From:  Robin Barker <rmb1@cise.npl.co.uk>
 Msg-ID:  <3180.9703270906@tempest.cise.npl.co.uk>
   Date:  Thu, 27 Mar 97 09:06:14 GMT
  Files:  installhtml

  Title:  "Make perlbug say that it's only for core Perl bugs"
   From:  Chip Salzenberg
  Files:  utils/perlbug.PL

 DOCUMENTATION

  Title:  "Document autouse and constant; update diagnostics"
   From:  Chip Salzenberg
  Files:  pod/perldelta.pod

  Title:  "Suggest to upgraders that they try '-w' again"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703251901.UAA15982@bombur2.uio.no>
   Date:  Tue, 25 Mar 1997 20:01:26 +0100 (MET)
  Files:  pod/perldelta.pod

    (applied based on p5p patch as commit id 4176c059b9ba6b022e99c44270434a5c3e415b73)

  Title:  "Improve and update documentation of constant subs"
   From:  Tom Phoenix <rootbeer@teleport.com>
 Msg-ID:  <Pine.GSO.3.96.970331122546.14185C-100000@kelly.teleport.com>
   Date:  Mon, 31 Mar 1997 13:05:54 -0800 (PST)
  Files:  pod/perlsub.pod

  Title:  "Improve documentation of C<return>"
   From:  Chip Salzenberg
  Files:  pod/perlfunc.pod pod/perlsub.pod

  Title:  "perlfunc.pod patch"
   From:  Gisle Aas
 Msg-ID:  <199703262159.WAA17531@furubotn.sn.no>
   Date:  Wed, 26 Mar 1997 22:59:23 +0100
  Files:  pod/perlfunc.pod

    (applied based on p5p patch as commit id 35a731fcbcd7860eb497d6598f3f77b8746319c4)

  Title:  "Use 'while (defined($x = <>)) {}', per <gnat@frii.com>"
   From:  Chip Salzenberg
  Files:  configpm lib/Term/Cap.pm perlsh pod/perlipc.pod pod/perlop.pod
          pod/perlsub.pod pod/perlsyn.pod pod/perltrap.pod
          pod/perlvar.pod win32/bin/search.bat

  Title:  "Document and test C<%> behavior with negative operands"
   From:  Chip Salzenberg
  Files:  pod/perlop.pod t/op/arith.t

  Title:  "Update docs on $]"
   From:  Chip Salzenberg
  Files:  pod/perlvar.pod

  Title:  "perlvar.pod patch"
   From:  Gisle Aas
 Msg-ID:  <199703261254.NAA10237@bergen.sn.no>
   Date:  Wed, 26 Mar 1997 13:54:00 +0100
  Files:  pod/perlvar.pod

    (applied based on p5p patch as commit id 0aa182cb0caa3829032904b9754807b1b7418509)

  Title:  "Fix example of C<or> vs. C<||>"
   From:  Chip Salzenberg
  Files:  pod/perlsyn.pod

  Title:  "Pod usage and spelling patch"
   From:  Larry W. Virden
  Files:  pod/*.pod

  Title:  "Pod updates"
   From:  "Cary D. Renzema" <caryr@mxim.com>
 Msg-ID:  <199703262353.PAA01819@macs.mxim.com>
   Date:  Wed, 26 Mar 1997 15:53:22 -0800 (PST)
  Files:  pod/*.pod

    (applied based on p5p patch as commit id 5695b28edc67a3f45e8a0f25755d07afef3660ac)

1 files changed, 162 insertions, 0 deletions

diff --git a/lib/constant.pm b/lib/constant.pm
new file mode 100644
index 0000000000..4416cf2ade
--- /dev/null
+++ b/lib/constant.pm
@@ -0,0 +1,162 @@
+package constant;
+
+$VERSION = '1.00';
+
+=head1 NAME
+
+constant - Perl pragma to declare constants
+
+=head1 SYNOPSIS
+
+    use constant BUFFER_SIZE	=> 4096;
+    use constant ONE_YEAR	=> 365.2425 * 24 * 60 * 60;
+    use constant PI		=> 4 * atan2 1, 1;
+    use constant DEBUGGING	=> 0;
+    use constant ORACLE		=> 'oracle@cs.indiana.edu';
+    use constant USERNAME	=> scalar getpwuid($<);
+    use constant USERINFO	=> getpwuid($<);
+
+    sub deg2rad { PI * $_[0] / 180 }
+
+    print "This line does nothing"		unless DEBUGGING;
+
+=head1 DESCRIPTION
+
+This will declare a symbol to be a constant with the given scalar
+or list value.
+
+When you declare a constant such as C<PI> using the method shown
+above, each machine your script runs upon can have as many digits
+of accuracy as it can use. Also, your program will be easier to
+read, more likely to be maintained (and maintained correctly), and
+far less likely to send a space probe to the wrong planet because
+nobody noticed the one equation in which you wrote C<3.14195>.
+
+=head1 NOTES
+
+The value or values are evaluated in a list context. You may override
+this with C<scalar> as shown above.
+
+These constants do not directly interpolate into double-quotish
+strings, although you may do so indirectly. (See L<perlref> for
+details about how this works.)
+
+    print "The value of PI is @{[ PI ]}.\n";
+
+List constants are returned as lists, not as arrays.
+
+    $homedir = USERINFO[7];		# WRONG
+    $homedir = (USERINFO)[7];		# Right
+
+The use of all caps for constant names is merely a convention,
+although it is recommended in order to make constants stand out
+and to help avoid collisions with other barewords, keywords, and
+subroutine names. Constant names must begin with a letter.
+
+Constant symbols are package scoped (rather than block scoped, as
+C<use strict> is). That is, you can refer to a constant from package
+Other as C<Other::CONST>.
+
+As with all C<use> directives, defining a constant happens at
+compile time. Thus, it's probably not correct to put a constant
+declaration inside of a conditional statement (like C<if ($foo)
+{ use constant ... }>).
+
+Omitting the value for a symbol gives it the value of C<undef> in
+a scalar context or the empty list, C<()>, in a list context. This
+isn't so nice as it may sound, though, because in this case you
+must either quote the symbol name, or use a big arrow, (C<=E<gt>>),
+with nothing to point to. It is probably best to declare these
+explicitly.
+
+    use constant UNICORNS	=> ();
+    use constant LOGFILE	=> undef;
+
+The result from evaluating a list constant in a scalar context is
+not documented, and is B<not> guaranteed to be any particular value
+in the future. In particular, you should not rely upon it being
+the number of elements in the list, especially since it is not
+B<necessarily> that value in the current implementation.
+
+Magical values, tied values, and references can be made into
+constants at compile time, allowing for way cool stuff like this.
+
+    use constant E2BIG => ($! = 7);
+    print   E2BIG, "\n";	# something like "Arg list too long"
+    print 0+E2BIG, "\n";	# "7"
+
+=head1 TECHNICAL NOTE
+
+In the current implementation, scalar constants are actually
+inlinable subroutines. As of version 5.004 of Perl, the appropriate
+scalar constant is inserted directly in place of some subroutine
+calls, thereby saving the overhead of a subroutine call. See
+L<perlsub/"Constant Functions"> for details about how and when this
+happens.
+
+=head1 BUGS
+
+In the current version of Perl, list constants are not inlined
+and some symbols may be redefined without generating a warning.
+
+It is not possible to have a subroutine or keyword with the same
+name as a constant. This is probably a Good Thing.
+
+Unlike constants in some languages, these cannot be overridden
+on the command line or via environment variables.
+
+=head1 AUTHOR
+
+Tom Phoenix, E<lt>F<rootbeer@teleport.com>E<gt>, with help from
+many other folks.
+
+=head1 COPYRIGHT
+
+Copyright (C) 1997, Tom Phoenix
+
+This module is free software; you can redistribute it or modify it
+under the same terms as Perl itself.
+
+=cut
+
+use strict;
+use Carp;
+use vars qw($VERSION);
+
+#=======================================================================
+
+# Some of this stuff didn't work in version 5.003, alas.
+require 5.003_20;
+
+#=======================================================================
+# import() - import symbols into user's namespace
+#
+# What we actually do is define a function in the caller's namespace
+# which returns the value. The function we create will normally
+# be inlined as a constant, thereby avoiding further sub calling 
+# overhead.
+#=======================================================================
+sub import {
+    my $class = shift;
+    my $name = shift or return;			# Ignore 'use constant;'
+    croak qq{Can't define "$name" as constant} .
+	    qq{ (name contains invalid characters or is empty)}
+	unless $name =~ /^[^\W_0-9]\w*$/;
+
+    my $pkg = caller;
+    {
+	no strict 'refs';
+	if (@_ == 1) {
+	    my $scalar = $_[0];
+	    *{"${pkg}::$name"} = sub () { $scalar };
+	} elsif (@_) {
+	    my @list = @_;
+	    *{"${pkg}::$name"} = sub () { @list };
+	} else {
+	    *{"${pkg}::$name"} = sub () { };
+	}
+    }
+
+}
+
+1;