struct regexp *
regexp_union_n(struct info *info, int n, struct regexp **r) {
size_t len = 0;
char *pat = NULL, *p, *expanded = NULL;
int nnocase = 0, npresent = 0;
int ret;
for (int i=0; i < n; i++)
if (r[i] != NULL) {
len += strlen(r[i]->pattern->str) + strlen("()|");
npresent += 1;
if (r[i]->nocase)
nnocase += 1;
}
bool mixedcase = nnocase > 0 && nnocase < npresent;
if (len == 0)
return NULL;
if (ALLOC_N(pat, len) < 0)
return NULL;
p = pat;
int added = 0;
for (int i=0; i < n; i++) {
if (r[i] == NULL)
continue;
if (added > 0)
*p++ = '|';
*p++ = '(';
if (mixedcase && r[i]->nocase) {
expanded = regexp_expand_nocase(r[i]);
ERR_BAIL(r[i]->info);
len += strlen(expanded) - strlen(r[i]->pattern->str);
ret = REALLOC_N(pat, len);
ERR_NOMEM(ret < 0, info);
p = pat + strlen(pat);
p = stpcpy(p, expanded);
FREE(expanded);
} else {
p = stpcpy(p, r[i]->pattern->str);
}
*p++ = ')';
added += 1;
}
*p = '\0';
return make_regexp(info, pat, nnocase == npresent);
error:
FREE(expanded);
FREE(pat);
return NULL;
}
static char *append_expanded(struct regexp *r, char **pat, char *p,
size_t *len) {
char *expanded = NULL;
size_t ofs = p - *pat;
int ret;
expanded = regexp_expand_nocase(r);
ERR_BAIL(r->info);
*len += strlen(expanded) - strlen(r->pattern->str);
ret = REALLOC_N(*pat, *len);
ERR_NOMEM(ret < 0, r->info);
p = stpcpy(*pat + ofs, expanded);
error:
FREE(expanded);
return p;
}
