text-regex.c

   1 #include <stdlib.h>
   2 #include <regex.h>
   3
   4 #include "text-regex.h"
   5
   6 struct Regex {
   7         regex_t regex;
   8 };
   9
  10 Regex *text_regex_new(void) {
  11         Regex *r = calloc(1, sizeof(Regex));
  12         if (!r)
  13                 return NULL;
  14         regcomp(&r->regex, "\0\0", 0); /* this should not match anything */
  15         return r;
  16 }
  17
  18 int text_regex_compile(Regex *regex, const char *string, int cflags) {
  19         int r = regcomp(&regex->regex, string, cflags);
  20         if (r)
  21                 regcomp(&regex->regex, "\0\0", 0);
  22         return r;
  23 }
  24
  25 void text_regex_free(Regex *r) {
  26         if (!r)
  27                 return;
  28         regfree(&r->regex);
  29         free(r);
  30 }
  31
  32 int text_search_range_forward(Text *txt, size_t pos, size_t len, Regex *r, size_t nmatch, RegexMatch pmatch[], int eflags) {
  33         char *buf = text_bytes_alloc0(txt, pos, len);
  34         if (!buf)
  35                 return REG_NOMATCH;
  36         regmatch_t match[nmatch];
  37         int ret = regexec(&r->regex, buf, nmatch, match, eflags);
  38         if (!ret) {
  39                 for (size_t i = 0; i < nmatch; i++) {
  40                         pmatch[i].start = match[i].rm_so == -1 ? EPOS : pos + match[i].rm_so;
  41                         pmatch[i].end = match[i].rm_eo == -1 ? EPOS : pos + match[i].rm_eo;
  42                 }
  43         }
  44         free(buf);
  45         return ret;
  46 }
  47
  48 int text_search_range_backward(Text *txt, size_t pos, size_t len, Regex *r, size_t nmatch, RegexMatch pmatch[], int eflags) {
  49         char *buf = text_bytes_alloc0(txt, pos, len);
  50         if (!buf)
  51                 return REG_NOMATCH;
  52         regmatch_t match[nmatch];
  53         char *cur = buf;
  54         int ret = REG_NOMATCH;
  55         while (!regexec(&r->regex, cur, nmatch, match, eflags)) {
  56                 ret = 0;
  57                 for (size_t i = 0; i < nmatch; i++) {
  58                         pmatch[i].start = match[i].rm_so == -1 ? EPOS : pos + (size_t)(cur - buf) + match[i].rm_so;
  59                         pmatch[i].end = match[i].rm_eo == -1 ? EPOS : pos + (size_t)(cur - buf) + match[i].rm_eo;
  60                 }
  61                 cur += match[0].rm_eo;
  62         }
  63         free(buf);
  64         return ret;
  65 }