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|
/* Copyright (C) 1995,1996,1997,1999,2000,2001 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
* As a special exception, the Free Software Foundation gives permission
* for additional uses of the text contained in its release of GUILE.
*
* The exception is that, if you link the GUILE library with other files
* to produce an executable, this does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* Your use of that executable is in no way restricted on account of
* linking the GUILE library code into it.
*
* This exception does not however invalidate any other reasons why
* the executable file might be covered by the GNU General Public License.
*
* This exception applies only to the code released by the
* Free Software Foundation under the name GUILE. If you copy
* code from other Free Software Foundation releases into a copy of
* GUILE, as the General Public License permits, the exception does
* not apply to the code that you add in this way. To avoid misleading
* anyone as to the status of such modified files, you must delete
* this exception notice from them.
*
* If you write modifications of your own for GUILE, it is your choice
* whether to permit this exception to apply to your modifications.
* If you do not wish that, delete this exception notice. */
/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
#include <stdio.h>
#include "libguile/_scm.h"
#include "libguile/chars.h"
#include "libguile/eval.h"
#include "libguile/unif.h"
#include "libguile/keywords.h"
#include "libguile/alist.h"
#include "libguile/srcprop.h"
#include "libguile/hashtab.h"
#include "libguile/hash.h"
#include "libguile/ports.h"
#include "libguile/root.h"
#include "libguile/strings.h"
#include "libguile/vectors.h"
#include "libguile/validate.h"
#include "libguile/read.h"
SCM_SYMBOL (scm_keyword_prefix, "prefix");
scm_option_t scm_read_opts[] = {
{ SCM_OPTION_BOOLEAN, "copy", 0,
"Copy source code expressions." },
{ SCM_OPTION_BOOLEAN, "positions", 0,
"Record positions of source code expressions." },
{ SCM_OPTION_BOOLEAN, "case-insensitive", 0,
"Convert symbols to lower case."},
{ SCM_OPTION_SCM, "keywords", SCM_UNPACK (SCM_BOOL_F),
"Style of keyword recognition: #f or 'prefix"}
};
SCM_DEFINE (scm_read_options, "read-options-interface", 0, 1, 0,
(SCM setting),
"Option interface for the read options. Instead of using\n"
"this procedure directly, use the procedures @code{read-enable},\n"
"@code{read-disable}, @code{read-set!} and @var{read-options}.")
#define FUNC_NAME s_scm_read_options
{
SCM ans = scm_options (setting,
scm_read_opts,
SCM_N_READ_OPTIONS,
FUNC_NAME);
if (SCM_COPY_SOURCE_P)
SCM_RECORD_POSITIONS_P = 1;
return ans;
}
#undef FUNC_NAME
/* An association list mapping extra hash characters to procedures. */
static SCM *scm_read_hash_procedures;
SCM_DEFINE (scm_read, "read", 0, 1, 0,
(SCM port),
"Read an s-expression from the input port @var{port}, or from\n"
"the current input port if @var{port} is not specified.\n"
"Any whitespace before the next token is discarded.")
#define FUNC_NAME s_scm_read
{
int c;
SCM tok_buf, copy;
if (SCM_UNBNDP (port))
port = scm_cur_inp;
SCM_VALIDATE_OPINPORT (1,port);
c = scm_flush_ws (port, (char *) NULL);
if (EOF == c)
return SCM_EOF_VAL;
scm_ungetc (c, port);
tok_buf = scm_allocate_string (30);
return scm_lreadr (&tok_buf, port, ©);
}
#undef FUNC_NAME
char *
scm_grow_tok_buf (SCM *tok_buf)
{
size_t oldlen = SCM_STRING_LENGTH (*tok_buf);
SCM newstr = scm_allocate_string (2 * oldlen);
size_t i;
for (i = 0; i != oldlen; ++i)
SCM_STRING_CHARS (newstr) [i] = SCM_STRING_CHARS (*tok_buf) [i];
*tok_buf = newstr;
return SCM_STRING_CHARS (newstr);
}
int
scm_flush_ws (SCM port, const char *eoferr)
{
register int c;
while (1)
switch (c = scm_getc (port))
{
case EOF:
goteof:
if (eoferr)
{
if (!SCM_FALSEP (SCM_FILENAME (port)))
scm_misc_error (eoferr,
"end of file in ~A",
SCM_LIST1 (SCM_FILENAME (port)));
else
scm_misc_error (eoferr, "end of file", SCM_EOL);
}
return c;
case ';':
lp:
switch (c = scm_getc (port))
{
case EOF:
goto goteof;
default:
goto lp;
case SCM_LINE_INCREMENTORS:
break;
}
break;
case SCM_LINE_INCREMENTORS:
case SCM_SINGLE_SPACES:
case '\t':
break;
default:
return c;
}
}
int
scm_casei_streq (char *s1, char *s2)
{
while (*s1 && *s2)
if (scm_downcase((int)*s1) != scm_downcase((int)*s2))
return 0;
else
{
++s1;
++s2;
}
return !(*s1 || *s2);
}
/* recsexpr is used when recording expressions
* constructed by read:sharp.
*/
#ifndef DEBUG_EXTENSIONS
#define recsexpr(obj, line, column, filename) (obj)
#else
static SCM
recsexpr (SCM obj, long line, int column, SCM filename)
{
if (!SCM_CONSP(obj)) {
return obj;
} else {
SCM tmp = obj, copy;
/* If this sexpr is visible in the read:sharp source, we want to
keep that information, so only record non-constant cons cells
which haven't previously been read by the reader. */
if (SCM_FALSEP (scm_whash_lookup (scm_source_whash, obj)))
{
if (SCM_COPY_SOURCE_P)
{
copy = scm_cons (recsexpr (SCM_CAR (obj), line, column, filename),
SCM_UNDEFINED);
while ((tmp = SCM_CDR (tmp)) && SCM_CONSP (tmp))
{
SCM_SETCDR (copy, scm_cons (recsexpr (SCM_CAR (tmp),
line,
column,
filename),
SCM_UNDEFINED));
copy = SCM_CDR (copy);
}
SCM_SETCDR (copy, tmp);
}
else
{
recsexpr (SCM_CAR (obj), line, column, filename);
while ((tmp = SCM_CDR (tmp)) && SCM_CONSP (tmp))
recsexpr (SCM_CAR (tmp), line, column, filename);
copy = SCM_UNDEFINED;
}
scm_whash_insert (scm_source_whash,
obj,
scm_make_srcprops (line,
column,
filename,
copy,
SCM_EOL));
}
return obj;
}
}
#endif
/* Consume an SCSH-style block comment. Assume that we've already
read the initial `#!', and eat characters until we get a
newline/exclamation-point/sharp-sign/newline sequence. */
static void
skip_scsh_block_comment (SCM port)
#define FUNC_NAME "skip_scsh_block_comment"
{
/* Is this portable? Dear God, spare me from the non-eight-bit
characters. But is it tasteful? */
long history = 0;
for (;;)
{
int c = scm_getc (port);
if (c == EOF)
SCM_MISC_ERROR ("unterminated `#! ... !#' comment", SCM_EOL);
history = ((history << 8) | (c & 0xff)) & 0xffffffff;
/* Were the last four characters read "\n!#\n"? */
if (history == (('\n' << 24) | ('!' << 16) | ('#' << 8) | '\n'))
return;
}
}
#undef FUNC_NAME
static SCM scm_get_hash_procedure(int c);
static char s_list[]="list";
SCM
scm_lreadr (SCM *tok_buf,SCM port,SCM *copy)
#define FUNC_NAME "scm_lreadr"
{
int c;
size_t j;
SCM p;
tryagain:
c = scm_flush_ws (port, s_scm_read);
tryagain_no_flush_ws:
switch (c)
{
case EOF:
return SCM_EOF_VAL;
case '(':
return SCM_RECORD_POSITIONS_P
? scm_lreadrecparen (tok_buf, port, s_list, copy)
: scm_lreadparen (tok_buf, port, s_list, copy);
case ')':
SCM_MISC_ERROR ("unexpected \")\"", SCM_EOL);
goto tryagain;
case '\'':
p = scm_sym_quote;
goto recquote;
case '`':
p = scm_sym_quasiquote;
goto recquote;
case ',':
c = scm_getc (port);
if ('@' == c)
p = scm_sym_uq_splicing;
else
{
scm_ungetc (c, port);
p = scm_sym_unquote;
}
recquote:
p = scm_cons2 (p,
scm_lreadr (tok_buf, port, copy),
SCM_EOL);
if (SCM_RECORD_POSITIONS_P)
scm_whash_insert (scm_source_whash,
p,
scm_make_srcprops (SCM_LINUM (port),
SCM_COL (port) - 1,
SCM_FILENAME (port),
SCM_COPY_SOURCE_P
? (*copy = scm_cons2 (SCM_CAR (p),
SCM_CAR (SCM_CDR (p)),
SCM_EOL))
: SCM_UNDEFINED,
SCM_EOL));
return p;
case '#':
c = scm_getc (port);
switch (c)
{
case '(':
p = scm_lreadparen (tok_buf, port, "vector", copy);
return SCM_NULLP (p) ? scm_nullvect : scm_vector (p);
case 't':
case 'T':
return SCM_BOOL_T;
case 'f':
case 'F':
return SCM_BOOL_F;
case 'b':
case 'B':
case 'o':
case 'O':
case 'd':
case 'D':
case 'x':
case 'X':
case 'i':
case 'I':
case 'e':
case 'E':
scm_ungetc (c, port);
c = '#';
goto num;
case '!':
/* start of a shell script. Parse as a block comment,
terminated by !#, just like SCSH. */
skip_scsh_block_comment (port);
/* EOF is not an error here */
c = scm_flush_ws (port, (char *)NULL);
goto tryagain_no_flush_ws;
#ifdef HAVE_ARRAYS
case '*':
j = scm_read_token (c, tok_buf, port, 0);
p = scm_istr2bve (SCM_STRING_CHARS (*tok_buf) + 1, (long) (j - 1));
if (SCM_NFALSEP (p))
return p;
else
goto unkshrp;
#endif
case '{':
j = scm_read_token (c, tok_buf, port, 1);
return scm_mem2symbol (SCM_STRING_CHARS (*tok_buf), j);
case '\\':
c = scm_getc (port);
j = scm_read_token (c, tok_buf, port, 0);
if (j == 1)
return SCM_MAKE_CHAR (c);
if (c >= '0' && c < '8')
{
p = scm_istr2int (SCM_STRING_CHARS (*tok_buf), (long) j, 8);
if (SCM_NFALSEP (p))
return SCM_MAKE_CHAR (SCM_INUM (p));
}
for (c = 0; c < scm_n_charnames; c++)
if (scm_charnames[c]
&& (scm_casei_streq (scm_charnames[c], SCM_STRING_CHARS (*tok_buf))))
return SCM_MAKE_CHAR (scm_charnums[c]);
SCM_MISC_ERROR ("unknown # object", SCM_EOL);
/* #:SYMBOL is a syntax for keywords supported in all contexts. */
case ':':
j = scm_read_token ('-', tok_buf, port, 0);
p = scm_mem2symbol (SCM_STRING_CHARS (*tok_buf), j);
return scm_make_keyword_from_dash_symbol (p);
default:
callshrp:
{
SCM sharp = scm_get_hash_procedure (c);
if (SCM_NIMP (sharp))
{
int line = SCM_LINUM (port);
int column = SCM_COL (port) - 2;
SCM got;
got = scm_apply (sharp,
SCM_MAKE_CHAR (c),
scm_acons (port, SCM_EOL, SCM_EOL));
if (SCM_EQ_P (got, SCM_UNSPECIFIED))
goto unkshrp;
if (SCM_RECORD_POSITIONS_P)
return *copy = recsexpr (got, line, column,
SCM_FILENAME (port));
else
return got;
}
}
unkshrp:
scm_misc_error (s_scm_read, "Unknown # object: ~S",
SCM_LIST1 (SCM_MAKE_CHAR (c)));
}
case '"':
j = 0;
while ('"' != (c = scm_getc (port)))
{
if (c == EOF)
SCM_MISC_ERROR ("end of file in string constant", SCM_EOL);
while (j + 2 >= SCM_STRING_LENGTH (*tok_buf))
scm_grow_tok_buf (tok_buf);
if (c == '\\')
switch (c = scm_getc (port))
{
case '\n':
continue;
case '0':
c = '\0';
break;
case 'f':
c = '\f';
break;
case 'n':
c = '\n';
break;
case 'r':
c = '\r';
break;
case 't':
c = '\t';
break;
case 'a':
c = '\007';
break;
case 'v':
c = '\v';
break;
}
SCM_STRING_CHARS (*tok_buf)[j] = c;
++j;
}
if (j == 0)
return scm_nullstr;
SCM_STRING_CHARS (*tok_buf)[j] = 0;
{
SCM str;
str = scm_makfromstr (SCM_STRING_CHARS (*tok_buf), j, 0);
return str;
}
case'0':case '1':case '2':case '3':case '4':
case '5':case '6':case '7':case '8':case '9':
case '.':
case '-':
case '+':
num:
j = scm_read_token (c, tok_buf, port, 0);
p = scm_istring2number (SCM_STRING_CHARS (*tok_buf), (long) j, 10L);
if (SCM_NFALSEP (p))
return p;
if (c == '#')
{
if ((j == 2) && (scm_getc (port) == '('))
{
scm_ungetc ('(', port);
c = SCM_STRING_CHARS (*tok_buf)[1];
goto callshrp;
}
SCM_MISC_ERROR ("unknown # object", SCM_EOL);
}
goto tok;
case ':':
if (SCM_EQ_P (SCM_PACK (SCM_KEYWORD_STYLE), scm_keyword_prefix))
{
j = scm_read_token ('-', tok_buf, port, 0);
p = scm_mem2symbol (SCM_STRING_CHARS (*tok_buf), j);
return scm_make_keyword_from_dash_symbol (p);
}
/* fallthrough */
default:
j = scm_read_token (c, tok_buf, port, 0);
/* fallthrough */
tok:
return scm_mem2symbol (SCM_STRING_CHARS (*tok_buf), j);
}
}
#undef FUNC_NAME
#ifdef _UNICOS
_Pragma ("noopt"); /* # pragma _CRI noopt */
#endif
size_t
scm_read_token (int ic, SCM *tok_buf, SCM port, int weird)
{
register size_t j;
register int c;
register char *p;
c = (SCM_CASE_INSENSITIVE_P ? scm_downcase(ic) : ic);
p = SCM_STRING_CHARS (*tok_buf);
if (weird)
j = 0;
else
{
j = 0;
while (j + 2 >= SCM_STRING_LENGTH (*tok_buf))
p = scm_grow_tok_buf (tok_buf);
p[j] = c;
++j;
}
while (1)
{
while (j + 2 >= SCM_STRING_LENGTH (*tok_buf))
p = scm_grow_tok_buf (tok_buf);
c = scm_getc (port);
switch (c)
{
case '(':
case ')':
case '"':
case ';':
case SCM_WHITE_SPACES:
case SCM_LINE_INCREMENTORS:
if (weird)
goto default_case;
scm_ungetc (c, port);
case EOF:
eof_case:
p[j] = 0;
return j;
case '\\':
if (!weird)
goto default_case;
else
{
c = scm_getc (port);
if (c == EOF)
goto eof_case;
else
goto default_case;
}
case '}':
if (!weird)
goto default_case;
c = scm_getc (port);
if (c == '#')
{
p[j] = 0;
return j;
}
else
{
scm_ungetc (c, port);
c = '}';
goto default_case;
}
default:
default_case:
{
c = (SCM_CASE_INSENSITIVE_P ? scm_downcase(c) : c);
p[j] = c;
++j;
}
}
}
}
#ifdef _UNICOS
_Pragma ("opt"); /* # pragma _CRI opt */
#endif
SCM
scm_lreadparen (SCM *tok_buf, SCM port, char *name, SCM *copy)
#define FUNC_NAME "scm_lreadparen"
{
SCM tmp;
SCM tl;
SCM ans;
int c;
c = scm_flush_ws (port, name);
if (')' == c)
return SCM_EOL;
scm_ungetc (c, port);
if (SCM_EQ_P (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
{
ans = scm_lreadr (tok_buf, port, copy);
closeit:
if (')' != (c = scm_flush_ws (port, name)))
SCM_MISC_ERROR ("missing close paren", SCM_EOL);
return ans;
}
ans = tl = scm_cons (tmp, SCM_EOL);
while (')' != (c = scm_flush_ws (port, name)))
{
scm_ungetc (c, port);
if (SCM_EQ_P (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
{
SCM_SETCDR (tl, scm_lreadr (tok_buf, port, copy));
goto closeit;
}
SCM_SETCDR (tl, scm_cons (tmp, SCM_EOL));
tl = SCM_CDR (tl);
}
return ans;
}
#undef FUNC_NAME
SCM
scm_lreadrecparen (SCM *tok_buf, SCM port, char *name, SCM *copy)
#define FUNC_NAME "scm_lreadrecparen"
{
register int c;
register SCM tmp;
register SCM tl, tl2 = SCM_EOL;
SCM ans, ans2 = SCM_EOL;
/* Need to capture line and column numbers here. */
int line = SCM_LINUM (port);
int column = SCM_COL (port) - 1;
c = scm_flush_ws (port, name);
if (')' == c)
return SCM_EOL;
scm_ungetc (c, port);
if (SCM_EQ_P (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
{
ans = scm_lreadr (tok_buf, port, copy);
if (')' != (c = scm_flush_ws (port, name)))
SCM_MISC_ERROR ("missing close paren", SCM_EOL);
return ans;
}
/* Build the head of the list structure. */
ans = tl = scm_cons (tmp, SCM_EOL);
if (SCM_COPY_SOURCE_P)
ans2 = tl2 = scm_cons (SCM_CONSP (tmp)
? *copy
: tmp,
SCM_EOL);
while (')' != (c = scm_flush_ws (port, name)))
{
SCM new_tail;
scm_ungetc (c, port);
if (SCM_EQ_P (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
{
SCM_SETCDR (tl, tmp = scm_lreadr (tok_buf, port, copy));
if (SCM_COPY_SOURCE_P)
SCM_SETCDR (tl2, scm_cons (SCM_CONSP (tmp)
? *copy
: tmp,
SCM_EOL));
if (')' != (c = scm_flush_ws (port, name)))
SCM_MISC_ERROR ("missing close paren", SCM_EOL);
goto exit;
}
new_tail = scm_cons (tmp, SCM_EOL);
SCM_SETCDR (tl, new_tail);
tl = new_tail;
if (SCM_COPY_SOURCE_P)
{
SCM new_tail2 = scm_cons (SCM_CONSP (tmp) ? *copy : tmp, SCM_EOL);
SCM_SETCDR (tl2, new_tail2);
tl2 = new_tail2;
}
}
exit:
scm_whash_insert (scm_source_whash,
ans,
scm_make_srcprops (line,
column,
SCM_FILENAME (port),
SCM_COPY_SOURCE_P
? *copy = ans2
: SCM_UNDEFINED,
SCM_EOL));
return ans;
}
#undef FUNC_NAME
/* Manipulate the read-hash-procedures alist. This could be written in
Scheme, but maybe it will also be used by C code during initialisation. */
SCM_DEFINE (scm_read_hash_extend, "read-hash-extend", 2, 0, 0,
(SCM chr, SCM proc),
"Install the procedure @var{proc} for reading expressions\n"
"starting with the character sequence @code{#} and @var{chr}.\n"
"@var{proc} will be called with two arguments: the character\n"
"@var{chr} and the port to read further data from. The object\n"
"returned will be the return value of @code{read}.")
#define FUNC_NAME s_scm_read_hash_extend
{
SCM this;
SCM prev;
SCM_VALIDATE_CHAR (1,chr);
SCM_ASSERT (SCM_FALSEP (proc) || SCM_NIMP(proc), proc, SCM_ARG2,
FUNC_NAME);
/* Check if chr is already in the alist. */
this = *scm_read_hash_procedures;
prev = SCM_BOOL_F;
while (1)
{
if (SCM_NULLP (this))
{
/* not found, so add it to the beginning. */
if (SCM_NFALSEP (proc))
{
*scm_read_hash_procedures =
scm_cons (scm_cons (chr, proc), *scm_read_hash_procedures);
}
break;
}
if (SCM_EQ_P (chr, SCM_CAAR (this)))
{
/* already in the alist. */
if (SCM_FALSEP (proc))
{
/* remove it. */
if (SCM_FALSEP (prev))
{
*scm_read_hash_procedures =
SCM_CDR (*scm_read_hash_procedures);
}
else
scm_set_cdr_x (prev, SCM_CDR (this));
}
else
{
/* replace it. */
scm_set_cdr_x (SCM_CAR (this), proc);
}
break;
}
prev = this;
this = SCM_CDR (this);
}
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
/* Recover the read-hash procedure corresponding to char c. */
static SCM
scm_get_hash_procedure (int c)
{
SCM rest = *scm_read_hash_procedures;
while (1)
{
if (SCM_NULLP (rest))
return SCM_BOOL_F;
if (SCM_CHAR (SCM_CAAR (rest)) == c)
return SCM_CDAR (rest);
rest = SCM_CDR (rest);
}
}
void
scm_init_read ()
{
scm_read_hash_procedures =
SCM_VARIABLE_LOC (scm_c_define ("read-hash-procedures", SCM_EOL));
scm_init_opts (scm_read_options, scm_read_opts, SCM_N_READ_OPTIONS);
#ifndef SCM_MAGIC_SNARFER
#include "libguile/read.x"
#endif
}
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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