New Zim utilties

src/utils.js

@@ -0,0 +1,32 @@
+export function levenshtein(a, b) {
+	const m = a.length, n = b.length;
+	if (!m) return n;
+	if (!n) return m;
+	const dp = Array.from({length: m + 1}, (_, i) => [i, ...Array(n).fill(0)]);
+	for (let j = 0; j <= n; j++) dp[0][j] = j;
+	for (let i = 1; i <= m; i++) {
+		for (let j = 1; j <= n; j++) {
+			dp[i][j] = a[i - 1] === b[j - 1]
+				? dp[i - 1][j - 1]
+				: 1 + Math.min(dp[i - 1][j - 1], dp[i - 1][j], dp[i][j - 1]);
+		}
+	}
+	return dp[m][n];
+}
+
+/** Normalized similarity in [0,1]: 1 - editDistance / maxLength. */
+export function similarity(a, b) {
+	a = a.toLowerCase(); b = b.toLowerCase();
+	return 1 - levenshtein(a, b) / Math.max(a.length, b.length, 1);
+}
+
+/** Compares `target` against one or more search terms; returns avg/max/per-term similarity. */
+export function fuzzyMatch(target, ...terms) {
+	if (!terms.length) throw new Error('Requires at least 1 term to compare');
+	const similarities = terms.map(t => similarity(target, t));
+	return {
+		avg: similarities.reduce((acc, s) => acc + s, 0) / similarities.length,
+		max: Math.max(...similarities),
+		similarities,
+	};
+}