TypedArray.prototype.copyWithin method

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.
 
+var $innerArrayCopyWithin;
+
 (function(global, exports) {
 
 'use strict';
 
 %CheckIsBootstrapping();
 
 var GlobalArray = global.Array;
 var GlobalSymbol = global.Symbol;
 
 // -------------------------------------------------------------------
 
-// ES6 draft 03-17-15, section 22.1.3.3
-function ArrayCopyWithin(target, start, end) {
-  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.copyWithin");
-
-  var array = TO_OBJECT_INLINE(this);
-  var length = $toLength(array.length);
-
+function InnerArrayCopyWithin(target, start, end, array, length) {
   target = TO_INTEGER(target);
   var to;
   if (target < 0) {
     to = $max(length + target, 0);
   } else {
     to = $min(target, length);
   }
 
   start = TO_INTEGER(start);
   var from;
@@ skipping 25 matching lines @@
     } else {
       delete array[to];
     }
     from = from + direction;
     to = to + direction;
     count--;
   }
 
   return array;
 }
+$innerArrayCopyWithin = InnerArrayCopyWithin;
+
+// ES6 draft 03-17-15, section 22.1.3.3
+function ArrayCopyWithin(target, start, end) {
+  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.copyWithin");
+
+  var array = TO_OBJECT_INLINE(this);
+  var length = $toLength(array.length);
+
+  return InnerArrayCopyWithin(target, start, end, array, length);
+}
 
 // ES6 draft 07-15-13, section 15.4.3.23
 function ArrayFind(predicate /* thisArg */) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.find");
 
   var array = $toObject(this);
   var length = $toInteger(array.length);
 
   if (!IS_SPEC_FUNCTION(predicate)) {
     throw MakeTypeError(kCalledNonCallable, predicate);
@@ skipping 203 matching lines @@
 
 // Set up the non-enumerable functions on the Array prototype object.
 $installFunctions(GlobalArray.prototype, DONT_ENUM, [
   "copyWithin", ArrayCopyWithin,
   "find", ArrayFind,
   "findIndex", ArrayFindIndex,
   "fill", ArrayFill
 ]);
 
 })