PIKApp/plug-ins/script-fu/libscriptfu/script-fu-regex.c

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2023-09-26 00:35:21 +02:00
/* PIKA - Photo and Image Kooker Application
* a rebranding of The GNU Image Manipulation Program (created with heckimp)
* A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
*
* Original copyright, applying to most contents (license remains unchanged):
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 3 of the License, 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 program. If not, see <https://www.gnu.org/licenses/>.
*/
/* Based on re.c
*
* Henry Spencer's implementation of Regular Expressions,
* used for TinyScheme
*
* Refurbished by Stephen Gildea
*
* Ported to GRegex and de-uglified by Michael Natterer
*/
#include "config.h"
#include "tinyscheme/scheme-private.h"
#include "script-fu-regex.h"
/* local function prototypes */
static pointer foreign_re_match (scheme *sc,
pointer args);
static void set_vector_elem (pointer vec,
int ielem,
pointer newel);
/* public functions */
void
script_fu_regex_init (scheme *sc)
{
sc->vptr->scheme_define (sc,
sc->global_env,
sc->vptr->mk_symbol(sc,"re-match"),
sc->vptr->mk_foreign_func(sc, foreign_re_match));
#if 0
sc->vptr->load_string
(sc,
";; return the substring of STRING matched in MATCH-VECTOR,\n"
";; the Nth subexpression match (default 0).\n"
"\n"
"(define (re-match-nth string match-vector . n)\n"
" (let ((n (if (pair? n) (car n) 0)))\n"
" (substring string (car (vector-ref match-vector n))\n"
" (cdr (vector-ref match-vector n)))))\n"
"(define (re-before-nth string match-vector . n)\n"
" (let ((n (if (pair? n) (car n) 0)))\n"
" (substring string 0 (car (vector-ref match-vector n)))))\n"
"(define (re-after-nth string match-vector . n)\n"
" (let ((n (if (pair? n) (car n) 0)))\n"
" (substring string (cdr (vector-ref match-vector n))\n"
" (string-length string))))\n");
#endif
}
/* private functions */
static pointer
foreign_re_match (scheme *sc,
pointer args)
{
pointer retval = sc->F;
gboolean success;
gboolean is_valid_utf8;
GRegex *regex;
pointer first_arg, second_arg;
pointer third_arg = sc->NIL;
char *string;
char *pattern;
int num = 0;
if (!((args != sc->NIL)
&& sc->vptr->is_string ((first_arg = sc->vptr->pair_car (args)))
&& (args = sc->vptr->pair_cdr (args))
&& sc->vptr->is_pair (args)
&& sc->vptr->is_string ((second_arg = sc->vptr->pair_car (args)))))
{
return sc->F;
}
pattern = sc->vptr->string_value (first_arg);
string = sc->vptr->string_value (second_arg);
is_valid_utf8 = g_utf8_validate (string, -1, NULL);
args = sc->vptr->pair_cdr (args);
if (args != sc->NIL)
{
if (!(sc->vptr->is_pair (args)
&& sc->vptr->is_vector ((third_arg = sc->vptr->pair_car (args)))))
{
return sc->F;
}
else
{
num = third_arg->_object._number.value.ivalue;
}
}
regex = g_regex_new (pattern, G_REGEX_EXTENDED, 0, NULL);
if (! regex)
return sc->F;
if (! num)
{
success = g_regex_match (regex, string, 0, NULL);
}
else
{
GMatchInfo *match_info;
gint i;
success = g_regex_match (regex, string, 0, &match_info);
for (i = 0; i < num; i++)
{
gint start, end;
g_match_info_fetch_pos (match_info, i, &start, &end);
if (is_valid_utf8)
{
start = g_utf8_pointer_to_offset (string, string + start);
end = g_utf8_pointer_to_offset (string, string + end);
}
#undef cons
set_vector_elem (third_arg, i,
sc->vptr->cons(sc,
sc->vptr->mk_integer(sc, start),
sc->vptr->mk_integer(sc, end)));
}
g_match_info_free (match_info);
}
if (success)
retval = sc->T;
g_regex_unref (regex);
return retval;
}
static void
set_vector_elem (pointer vec,
int ielem,
pointer newel)
{
int n = ielem / 2;
if (ielem % 2 == 0)
{
vec[1 + n]._object._cons._car = newel;
}
else
{
vec[1 + n]._object._cons._cdr = newel;
}
}