dmenu-custom/patch/fuzzymatch.c

84 lines
2.2 KiB
C

#include <math.h>
int
compare_distance(const void *a, const void *b)
{
struct item *da = *(struct item **) a;
struct item *db = *(struct item **) b;
if (!db)
return 1;
if (!da)
return -1;
return da->distance == db->distance ? 0 : da->distance < db->distance ? -1 : 1;
}
void
fuzzymatch(void)
{
/* bang - we have so much memory */
struct item *it;
struct item **fuzzymatches = NULL;
char c;
int number_of_matches = 0, i, pidx, sidx, eidx;
int text_len = strlen(text), itext_len;
matches = matchend = NULL;
/* walk through all items */
for (it = items; it && it->text; it++) {
if (text_len) {
itext_len = strlen(it->text);
pidx = 0; /* pointer */
sidx = eidx = -1; /* start of match, end of match */
/* walk through item text */
for (i = 0; i < itext_len && (c = it->text[i]); i++) {
/* fuzzy match pattern */
if (!fstrncmp(&text[pidx], &c, 1)) {
if (sidx == -1)
sidx = i;
pidx++;
if (pidx == text_len) {
eidx = i;
break;
}
}
}
/* build list of matches */
if (eidx != -1) {
/* compute distance */
/* add penalty if match starts late (log(sidx+2))
* add penalty for long a match without many matching characters */
it->distance = log(sidx + 2) + (double)(eidx - sidx - text_len);
/* fprintf(stderr, "distance %s %f\n", it->text, it->distance); */
appenditem(it, &matches, &matchend);
number_of_matches++;
}
} else {
appenditem(it, &matches, &matchend);
}
}
if (number_of_matches) {
/* initialize array with matches */
if (!(fuzzymatches = realloc(fuzzymatches, number_of_matches * sizeof(struct item*))))
die("cannot realloc %u bytes:", number_of_matches * sizeof(struct item*));
for (i = 0, it = matches; it && i < number_of_matches; i++, it = it->right) {
fuzzymatches[i] = it;
}
/* sort matches according to distance */
qsort(fuzzymatches, number_of_matches, sizeof(struct item*), compare_distance);
/* rebuild list of matches */
matches = matchend = NULL;
for (i = 0, it = fuzzymatches[i]; i < number_of_matches && it && \
it->text; i++, it = fuzzymatches[i]) {
appenditem(it, &matches, &matchend);
}
free(fuzzymatches);
}
curr = sel = matches;
calcoffsets();
}