[builtins] Implement Array.prototype.reduceRight in the CSA

src/js/typedarray.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
 
 // array.js has to come before typedarray.js for this to work
 var ArrayToString = utils.ImportNow("ArrayToString");
 var ArrayValues;
 var GetIterator;
 var GetMethod;
 var GlobalArray = global.Array;
 var GlobalArrayBuffer = global.ArrayBuffer;
 var GlobalArrayBufferPrototype = GlobalArrayBuffer.prototype;
 var GlobalObject = global.Object;
 var InnerArrayFilter;
 var InnerArrayFind;
 var InnerArrayFindIndex;
 var InnerArrayJoin;
-var InnerArrayReduceRight;
 var InnerArraySort;
 var InnerArrayToLocaleString;
 var InternalArray = utils.InternalArray;
 var MaxSimple;
 var MinSimple;
 var PackedArrayReverse;
 var SpeciesConstructor;
 var ToPositiveInteger;
 var ToIndex;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
@@ skipping 21 matching lines @@
 var GlobalTypedArray = %object_get_prototype_of(GlobalUint8Array);
 
 utils.Import(function(from) {
   ArrayValues = from.ArrayValues;
   GetIterator = from.GetIterator;
   GetMethod = from.GetMethod;
   InnerArrayFilter = from.InnerArrayFilter;
   InnerArrayFind = from.InnerArrayFind;
   InnerArrayFindIndex = from.InnerArrayFindIndex;
   InnerArrayJoin = from.InnerArrayJoin;
-  InnerArrayReduceRight = from.InnerArrayReduceRight;
   InnerArraySort = from.InnerArraySort;
   InnerArrayToLocaleString = from.InnerArrayToLocaleString;
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
   PackedArrayReverse = from.PackedArrayReverse;
   SpeciesConstructor = from.SpeciesConstructor;
   ToPositiveInteger = from.ToPositiveInteger;
   ToIndex = from.ToIndex;
 });
 
@@ skipping 485 matching lines @@
 // ES6 draft 07-15-13, section 22.2.3.19
 function TypedArrayReduce(callback, current) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
   return InnerTypedArrayReduce(
       callback, current, this, length, arguments.length);
 }
 %FunctionSetLength(TypedArrayReduce, 1);
 
+function InnerArrayReduceRight(callback, current, array, length,
+                               argumentsLength) {
+  if (!IS_CALLABLE(callback)) {
+    throw %make_type_error(kCalledNonCallable, callback);
+  }
+
+  var i = length - 1;
+  find_initial: if (argumentsLength < 2) {
+    for (; i >= 0; i--) {
+      if (i in array) {
+        current = array[i--];
+        break find_initial;
+      }
+    }
+    throw %make_type_error(kReduceNoInitial);
+  }
+
+  for (; i >= 0; i--) {
+    if (i in array) {
+      var element = array[i];
+      current = callback(current, element, i, array);
+    }
+  }
+  return current;
+}
 
 // ES6 draft 07-15-13, section 22.2.3.19
 function TypedArrayReduceRight(callback, current) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
   return InnerArrayReduceRight(callback, current, this, length,
                                arguments.length);
 }
 %FunctionSetLength(TypedArrayReduceRight, 1);
@@ skipping 149 matching lines @@
   %AddNamedProperty(GlobalNAME.prototype,
                     "constructor", global.NAME, DONT_ENUM);
   %AddNamedProperty(GlobalNAME.prototype,
                     "BYTES_PER_ELEMENT", ELEMENT_SIZE,
                     READ_ONLY | DONT_ENUM | DONT_DELETE);
 endmacro
 
 TYPED_ARRAYS(SETUP_TYPED_ARRAY)
 
 })