Array/TypedArray/ArrayBuffer method subclassing and @@species

src/js/arraybuffer.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.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var GlobalArrayBuffer = global.ArrayBuffer;
 var MakeTypeError;
 var MaxSimple;
 var MinSimple;
+var SpeciesConstructor;
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
+  SpeciesConstructor = from.SpeciesConstructor;
 });
 
 // -------------------------------------------------------------------
 
 function ArrayBufferGetByteLen() {
   if (!IS_ARRAYBUFFER(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'ArrayBuffer.prototype.byteLength', this);
   }
   return %_ArrayBufferGetByteLength(this);
@@ skipping 22 matching lines @@
   if (relativeEnd < 0) {
     fin = MaxSimple(byte_length + relativeEnd, 0);
   } else {
     fin = MinSimple(relativeEnd, byte_length);
   }
 
   if (fin < first) {
     fin = first;
   }
   var newLen = fin - first;
-  // TODO(dslomov): implement inheritance
-  var result = new GlobalArrayBuffer(newLen);
+  var constructor = SpeciesConstructor(this, GlobalArrayBuffer);
+  var result = new constructor(newLen);
+  if (!IS_ARRAYBUFFER(result)) {
+    throw MakeTypeError(kIncompatibleMethodReceiver,
+                        'ArrayBuffer.prototype.slice', result);
+  }
+  if (%_ArrayBufferGetByteLength(result) < newLen) {
+    throw MakeTypeError(kArrayBufferTooShort);
+  }
+  if (result === this) {
+    throw MakeTypeError(kArrayBufferSpeciesThis);
+  }
 
-  %ArrayBufferSliceImpl(this, result, first);
+  %ArrayBufferSliceImpl(this, result, first, newLen);
   return result;
 }
 
 utils.InstallGetter(GlobalArrayBuffer.prototype, "byteLength",
                     ArrayBufferGetByteLen);
 
 utils.InstallFunctions(GlobalArrayBuffer.prototype, DONT_ENUM, [
   "slice", ArrayBufferSlice
 ]);
 
 })