Implement ES5 Object.seal and Object.isSealed....

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 727 matching lines @@
   }
   for (var i = 0; i < key_values.length; i += 2) {
     var key = key_values[i];
     var desc = key_values[i + 1];
     DefineOwnProperty(obj, key, desc, true);
   }
   return obj;
 }
 
 
+// ES5 section 15.2.3.8.
+function ObjectSeal(obj) {
+  if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
+      !IS_UNDETECTABLE(obj)) {
+    throw MakeTypeError("obj_ctor_property_non_object", ["seal"]);
+  }
+  var names = ObjectGetOwnPropertyNames(obj);
+  for (var key in names) {
+    var name = names[key];
+    var desc = GetOwnProperty(obj, name);
+    if (desc.isConfigurable()) desc.setConfigurable(false);
+    DefineOwnProperty(obj, name, desc, true);
+  }  
+  ObjectPreventExtension(obj);
+}
+
+
 // ES5 section 15.2.3.9.
 function ObjectFreeze(obj) {
   if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
       !IS_UNDETECTABLE(obj)) {
     throw MakeTypeError("obj_ctor_property_non_object", ["freeze"]);
   }
   var names = ObjectGetOwnPropertyNames(obj);
   for (var key in names) {
     var name = names[key];
     var desc = GetOwnProperty(obj, name);
     if (IsDataDescriptor(desc)) desc.setWritable(false);
     if (desc.isConfigurable()) desc.setConfigurable(false);
     DefineOwnProperty(obj, name, desc, true);
   }  
   ObjectPreventExtension(obj);
 }
 
 
 // ES5 section 15.2.3.10
 function ObjectPreventExtension(obj) {
   if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
       !IS_UNDETECTABLE(obj)) {
     throw MakeTypeError("obj_ctor_property_non_object", ["preventExtension"]);
   }
   %PreventExtensions(obj);
   return obj;
 }
 
 
+// ES5 section 15.2.3.11
+function ObjectIsSealed(obj) {
+  if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
+      !IS_UNDETECTABLE(obj)) {
+    throw MakeTypeError("obj_ctor_property_non_object", ["isSealed"]);
+  }
+  var names = ObjectGetOwnPropertyNames(obj);
+  for (var key in names) {
+    var name = names[key];
+    var desc = GetOwnProperty(obj, name);
+    if (desc.isConfigurable()) return false;
+  }
+  if (!ObjectIsExtensible(obj)) {
+    return true;
+  }
+  return false;
+}
+
+
 // ES5 section 15.2.3.12
 function ObjectIsFrozen(obj) {
   if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
       !IS_UNDETECTABLE(obj)) {
     throw MakeTypeError("obj_ctor_property_non_object", ["isFrozen"]);
   }
   var names = ObjectGetOwnPropertyNames(obj);
   for (var key in names) {
     var name = names[key];
     var desc = GetOwnProperty(obj, name);
@@ skipping 49 matching lines @@
     "keys", ObjectKeys,
     "create", ObjectCreate,
     "defineProperty", ObjectDefineProperty,
     "defineProperties", ObjectDefineProperties,
     "freeze", ObjectFreeze,
     "getPrototypeOf", ObjectGetPrototypeOf,
     "getOwnPropertyDescriptor", ObjectGetOwnPropertyDescriptor,
     "getOwnPropertyNames", ObjectGetOwnPropertyNames,
     "isExtensible", ObjectIsExtensible,
     "isFrozen", ObjectIsFrozen,
-    "preventExtensions", ObjectPreventExtension
+    "isSealed", ObjectIsSealed,
+    "preventExtensions", ObjectPreventExtension,
+    "seal", ObjectSeal
   ));
 }
 
 SetupObject();
 
 
 // ----------------------------------------------------------------------------
 // Boolean
 
 function BooleanToString() {
@@ skipping 247 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();