Add a bit of documentation

src/main/js/jaroWinkler.js

@@ -24,39 +24,28 @@
 
 "use strict";
 
-const optionDefault = (template, options) => {
-    for (let prop in options)
-        if (options.hasOwnProperty(prop))
-            template[prop] = options[prop];
-
-    return template;
-};
-
-export const jaro_winkler = function (a, b, options) {
-    // Load default options
-    options = optionDefault({"caseSensitive": true}, options);
 
+/**
+ * Returns the similarity of the given strings.
+ *
+ * @param a {string} a string
+ * @param b {string} a string
+ * @param caseSensitive {boolean} whether the calculation should be case-sensitive
+ * @returns {number} the similarity of the given strings
+ */
+export const jaroWinkler = function (a, b, caseSensitive = true) {
     // Convert to lowercase if not case-sensitive
-    if (!options.caseSensitive) {
+    if (!caseSensitive) {
         a = a.toLowerCase();
         b = b.toLowerCase();
     }
 
-
-    const aLen = a.length;
-    const bLen = b.length;
-
-    // Short-circuit if either is empty
-    if (aLen === 0 || bLen === 0)
-        return 0;
-
-    // Short-circuit if exact match
-    if (a === b)
-        return 1;
+    if (a.length === 0 || b.length === 0) return 0;
+    if (a === b) return 1;
 
 
     // Calculate difference
-    const range = (Math.floor(Math.max(aLen, bLen) / 2)) - 1;
+    const range = Math.floor(Math.max(a.length, b.length) / 2) - 1;
     const aMatches = [];
     const bMatches = [];
     let low;
@@ -64,9 +53,9 @@ export const jaro_winkler = function (a, b, options) {
     let m = 0;
 
     // Find matches
-    for (let i = 0; i < aLen; i++) {
-        low = ((i >= range) ? i - range : 0);
-        high = ((i + range <= bLen) ? (i + range) : (bLen - 1));
+    for (let i = 0; i < a.length; i++) {
+        low = (i >= range) ? i - range : 0;
+        high = (i + range <= b.length) ? (i + range) : (b.length - 1);
 
         for (let j = low; j <= high; j++) {
             if (aMatches[i] !== true && bMatches[j] !== true && a[i] === b[j]) {
@@ -79,30 +68,27 @@ export const jaro_winkler = function (a, b, options) {
     }
 
     // Short-circuit if not matches found
-    if (m === 0)
-        return 0;
+    if (m === 0) return 0;
 
     // Count transpositions
     let k = 0;
     let numTrans = 0;
 
-    for (let i = 0; i < aLen; i++) {
+    for (let i = 0; i < a.length; i++) {
         if (aMatches[i] === true) {
             let j;
-            for (j = k; j < bLen; j++) {
+            for (j = k; j < b.length; j++) {
                 if (bMatches[j] === true) {
                     k = j + 1;
                     break;
                 }
             }
 
-            if (a[i] !== b[j]) {
-                numTrans++;
-            }
+            if (a[i] !== b[j]) numTrans++;
         }
     }
 
-    let weight = (((m / aLen) + (m / bLen) + (m - (numTrans / 2)) / m) / 3);
+    let weight = (m / a.length + m / b.length + (m - numTrans / 2) / m) / 3;
     let l = 0;
     const p = 0.1;