text-regex.c

   1 #include <stdlib.h>
   2 #include <regex.h>
   3
   4 #include "text-regex.h"
   5
   6 struct Regex {
   7         const char *string;
   8         regex_t regex;
   9 };
  10
  11 Regex *text_regex_new(void) {
  12         Regex *r = calloc(1, sizeof(Regex));
  13         if (!r)
  14                 return NULL;
  15         regcomp(&r->regex, "\0\0", 0); /* this should not match anything */
  16         return r;
  17 }
  18
  19 int text_regex_compile(Regex *regex, const char *string, int cflags) {
  20         regex->string = string;
  21         int r = regcomp(&regex->regex, string, cflags);
  22         if (r)
  23                 regcomp(&regex->regex, "\0\0", 0);
  24         return r;
  25 }
  26
  27 void text_regex_free(Regex *r) {
  28         if (!r)
  29                 return;
  30         regfree(&r->regex);
  31         free(r);
  32 }
  33
  34 int text_search_range_forward(Text *txt, size_t pos, size_t len, Regex *r, size_t nmatch, RegexMatch pmatch[], int eflags) {
  35         char *buf = malloc(len + 1);
  36         if (!buf)
  37                 return REG_NOMATCH;
  38         len = text_bytes_get(txt, pos, len, buf);
  39         buf[len] = '\0';
  40         regmatch_t match[nmatch];
  41         int ret = regexec(&r->regex, buf, nmatch, match, eflags);
  42         if (!ret) {
  43                 for (size_t i = 0; i < nmatch; i++) {
  44                         pmatch[i].start = match[i].rm_so == -1 ? EPOS : pos + match[i].rm_so;
  45                         pmatch[i].end = match[i].rm_eo == -1 ? EPOS : pos + match[i].rm_eo;
  46                 }
  47         }
  48         free(buf);
  49         return ret;
  50 }
  51
  52 int text_search_range_backward(Text *txt, size_t pos, size_t len, Regex *r, size_t nmatch, RegexMatch pmatch[], int eflags) {
  53         char *buf = malloc(len + 1);
  54         if (!buf)
  55                 return REG_NOMATCH;
  56         len = text_bytes_get(txt, pos, len, buf);
  57         buf[len] = '\0';
  58         regmatch_t match[nmatch];
  59         char *cur = buf;
  60         int ret = REG_NOMATCH;
  61         while (!regexec(&r->regex, cur, nmatch, match, eflags)) {
  62                 ret = 0;
  63                 for (size_t i = 0; i < nmatch; i++) {
  64                         pmatch[i].start = match[i].rm_so == -1 ? EPOS : pos + (size_t)(cur - buf) + match[i].rm_so;
  65                         pmatch[i].end = match[i].rm_eo == -1 ? EPOS : pos + (size_t)(cur - buf) + match[i].rm_eo;
  66                 }
  67                 cur += match[0].rm_eo;
  68         }
  69         free(buf);
  70         return ret;
  71 }