Implemented Object.keys.

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 258 matching lines @@
 
 
 function ObjectLookupSetter(name) {
   if (this == null) {
     throw new $TypeError('Object.prototype.__lookupSetter__: this is Null');
   }
   return %LookupAccessor(ToObject(this), ToString(name), SETTER);
 }
 
 
+function ObjectKeys(obj) {
+  if (!IS_OBJECT(obj) || IS_NULL_OR_UNDEFINED(obj))
+    throw MakeTypeError('object_keys_non_object', [obj]);
+  return %LocalKeys(obj);
+}
+
+
 %SetCode($Object, function(x) {
   if (%_IsConstructCall()) {
     if (x == null) return this;
     return ToObject(x);
   } else {
     if (x == null) return { };
     return ToObject(x);
   }
 });
 
 
 // ----------------------------------------------------------------------------
 
 
 function SetupObject() {
   // Setup non-enumerable functions on the Object.prototype object.
   InstallFunctions($Object.prototype, DONT_ENUM, $Array(
     "toString", ObjectToString,
     "toLocaleString", ObjectToLocaleString,
     "valueOf", ObjectValueOf,
     "hasOwnProperty", ObjectHasOwnProperty,
     "isPrototypeOf", ObjectIsPrototypeOf,
     "propertyIsEnumerable", ObjectPropertyIsEnumerable,
     "__defineGetter__", ObjectDefineGetter,
     "__lookupGetter__", ObjectLookupGetter,
     "__defineSetter__", ObjectDefineSetter,
     "__lookupSetter__", ObjectLookupSetter
   ));
+  InstallFunctions($Object, DONT_ENUM, $Array(
+    "keys", ObjectKeys
+  ));
 }
 
 SetupObject();
 
 
 // ----------------------------------------------------------------------------
 // Boolean
 
 function BooleanToString() {
   // NOTE: Both Boolean objects and values can enter here as
@@ skipping 252 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();