spmenu/libs/match.c

void
fuzzymatch(void)
{
	struct item *it;
	struct item **fuzzymatches = NULL;
    struct item *lhpprefix, *hpprefixend;
	lhpprefix = hpprefixend = 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 */
        if (sortmatches) 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]) {

            if (sortmatches && it->hp)
                appenditem(it, &lhpprefix, &hpprefixend);

            appenditem(it, &matches, &matchend);
		}
		free(fuzzymatches);
	}

    if (lhpprefix) {
		hpprefixend->right = matches;
		matches = lhpprefix;
	}

	curr = sel = matches;

    for (i = 0; i < preselected; i++) {
		if (sel && sel->right && (sel = sel->right) == next) {
			curr = next;
			calcoffsets();
		}
	}

	calcoffsets();
}

void
match(void)
{
	if (fuzzy) {
		fuzzymatch();
		return;
	}
	static char **tokv = NULL;
	static int tokn = 0;

	char buf[sizeof text], *s;
	int i, tokc = 0;
	size_t len, textsize;
    struct item *item, *lhpprefix, *lprefix, *lsubstr, *hpprefixend, *prefixend, *substrend;


	strcpy(buf, text);
	/* separate input text into tokens to be matched individually */
	for (s = strtok(buf, " "); s; tokv[tokc - 1] = s, s = strtok(NULL, " "))
		if (++tokc > tokn && !(tokv = realloc(tokv, ++tokn * sizeof *tokv)))
			die("cannot realloc %u bytes:", tokn * sizeof *tokv);
	len = tokc ? strlen(tokv[0]) : 0;

    matches = lhpprefix = lprefix = lsubstr = matchend = hpprefixend = prefixend = substrend = NULL;
	textsize = strlen(text) + 1;
	for (item = items; item && item->text; item++) {
		for (i = 0; i < tokc; i++)
			if (!fstrstr(item->text, tokv[i]))
				break;
		if (i != tokc) /* not all tokens match */
			continue;
        if (!sortmatches)
			appenditem(item, &matches, &matchend);
        else {
            /* exact matches go first, then prefixes with high priority, then prefixes, then substrings */
            if (item->hp && !fstrncmp(tokv[0], item->text, len))
			    appenditem(item, &lhpprefix, &hpprefixend);
            else if (!tokc || !fstrncmp(text, item->text, textsize))
				appenditem(item, &matches, &matchend);
			else if (!fstrncmp(tokv[0], item->text, len))
				appenditem(item, &lprefix, &prefixend);
			else
				appenditem(item, &lsubstr, &substrend);
		}
	}
    if (lhpprefix) {
		if (matches) {
			matchend->right = lhpprefix;
			lhpprefix->left = matchend;
		} else
			matches = lhpprefix;
		matchend = hpprefixend;
	}
	if (lprefix) {
		if (matches) {
			matchend->right = lprefix;
			lprefix->left = matchend;
		} else
			matches = lprefix;
		matchend = prefixend;
	}
	if (lsubstr) {
		if (matches) {
			matchend->right = lsubstr;
			lsubstr->left = matchend;
		} else
			matches = lsubstr;
		matchend = substrend;
	}
	curr = sel = matches;
	calcoffsets();
}

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;
}