Implement ES6 Array.of()

src/harmony-array.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 105 matching lines @@
   if ((end - i) > 0 && ObjectIsFrozen(array)) {
     throw MakeTypeError("array_functions_on_frozen",
                         ["Array.prototype.fill"]);
   }
 
   for (; i < end; i++)
     array[i] = value;
   return array;
 }
 
+// ES6, draft 05-22-14, section 22.1.2.3
+function ArrayOf() {
+  var length = %_ArgumentsLength();
+  var constructor = this;
+  // TODO: Implement IsConstructor (ES6 section 7.2.5)
+  var array = IS_SPEC_FUNCTION(constructor) ? new constructor(length) : [];
+  for (var i = 0; i < length; i++) {
+    %AddElement(array, i, %_Arguments(i), NONE);
+  }
+  array.length = length;
+  return array;
+}
+
 // -------------------------------------------------------------------
 
 function HarmonyArrayExtendArrayPrototype() {
   %CheckIsBootstrapping();
 
+  // Set up non-enumerable functions on the Array object.
+  InstallFunctions($Array, DONT_ENUM, $Array(
+    "of", ArrayOf
+  ));
+
   // Set up the non-enumerable functions on the Array prototype object.
   InstallFunctions($Array.prototype, DONT_ENUM, $Array(
     "find", ArrayFind,
     "findIndex", ArrayFindIndex,
     "fill", ArrayFill
   ));
 }
 
 HarmonyArrayExtendArrayPrototype();