Bug 769871 - Reimplement String.localeCompare per ECMA-402. r=jwalden

js/src/builtin/String.js

@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*global intl_Collator: false, */
+
+
+var collatorCache = new Record();
+
+
+/**
+ * Compare this String against that String, using the locale and collation
+ * options provided.
+ *
+ * Spec: ECMAScript Internationalization API Specification, 13.1.1.
+ */
+function String_localeCompare(that) {
+    // Steps 1-3.
+    CheckObjectCoercible(this);
+    var S = ToString(this);
+    var That = ToString(that);
+
+    // Steps 4-5.
+    var locales = arguments.length > 1 ? arguments[1] : undefined;
+    var options = arguments.length > 2 ? arguments[2] : undefined;
+
+    // Step 6.
+    var collator;
+    if (locales === undefined && options === undefined) {
+        // This cache only optimizes for the old ES5 localeCompare without
+        // locales and options.
+        if (collatorCache.collator === undefined)
+            collatorCache.collator = intl_Collator(locales, options);
+        collator = collatorCache.collator;
+    } else {
+        collator = intl_Collator(locales, options);
+    }
+
+    // Step 7.
+    return intl_CompareStrings(collator, S, That);
+}
+
+/**
+ * Compare String str1 against String str2, using the locale and collation
+ * options provided.
+ *
+ * Mozilla proprietary.
+ * Spec: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/String#String_generic_methods
+ */
+function String_static_localeCompare(str1, str2) {
+    if (arguments.length < 1)
+        ThrowError(JSMSG_MISSING_FUN_ARG, 0, "String.localeCompare");
+    var locales = arguments.length > 2 ? arguments[2] : undefined;
+    var options = arguments.length > 3 ? arguments[3] : undefined;
+    return callFunction(String_localeCompare, str1, str2, locales, options);
+}