Update Array Iterator to use numeric indexes

At the last face-to-face meeting it was decided that we should use
numeric indexes for the Array Iterator values.

https://github.com/rwldrn/tc39-notes/blob/master/es6/2013-07/july-24.md#514-keys-entries-return-numbers-for-array-index-properties

BUG=v8:2818
R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/21180008

Patch from Erik Arvidsson <arv@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16072 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/array-iterator.js

@@ -77,16 +77,15 @@ function ArrayIteratorNext() {
     return CreateIteratorResultObject(void 0, true);
   }
 
-  var elementKey = ToString(index);
   iterator[arrayIteratorNextIndexSymbol] = index + 1;
 
   if (itemKind == ARRAY_ITERATOR_KIND_VALUES)
-    return CreateIteratorResultObject(array[elementKey], false);
+    return CreateIteratorResultObject(array[index], false);
 
   if (itemKind == ARRAY_ITERATOR_KIND_ENTRIES)
-    return CreateIteratorResultObject([elementKey, array[elementKey]], false);
+    return CreateIteratorResultObject([index, array[index]], false);
 
-  return CreateIteratorResultObject(elementKey, false);
+  return CreateIteratorResultObject(index, false);
 }
 
 function ArrayEntries() {

test/mjsunit/harmony/array-iterator.js

@@ -39,7 +39,7 @@ function TestArrayPrototype() {
 TestArrayPrototype();
 
 function assertIteratorResult(value, done, result) {
-  assertEquals({ value: value, done: done}, result);
+  assertEquals({value: value, done: done}, result);
 }
 
 function TestValues() {
@@ -70,9 +70,9 @@ TestValuesMutate();
 function TestKeys() {
   var array = ['a', 'b', 'c'];
   var iterator = array.keys();
-  assertIteratorResult('0', false, iterator.next());
-  assertIteratorResult('1', false, iterator.next());
-  assertIteratorResult('2', false, iterator.next());
+  assertIteratorResult(0, false, iterator.next());
+  assertIteratorResult(1, false, iterator.next());
+  assertIteratorResult(2, false, iterator.next());
   assertIteratorResult(void 0, true, iterator.next());
 
   array.push('d');
@@ -83,11 +83,11 @@ TestKeys();
 function TestKeysMutate() {
   var array = ['a', 'b', 'c'];
   var iterator = array.keys();
-  assertIteratorResult('0', false, iterator.next());
-  assertIteratorResult('1', false, iterator.next());
-  assertIteratorResult('2', false, iterator.next());
+  assertIteratorResult(0, false, iterator.next());
+  assertIteratorResult(1, false, iterator.next());
+  assertIteratorResult(2, false, iterator.next());
   array.push('d');
-  assertIteratorResult('3', false, iterator.next());
+  assertIteratorResult(3, false, iterator.next());
   assertIteratorResult(void 0, true, iterator.next());
 }
 TestKeysMutate();
@@ -95,9 +95,9 @@ TestKeysMutate();
 function TestEntries() {
   var array = ['a', 'b', 'c'];
   var iterator = array.entries();
-  assertIteratorResult(['0', 'a'], false, iterator.next());
-  assertIteratorResult(['1', 'b'], false, iterator.next());
-  assertIteratorResult(['2', 'c'], false, iterator.next());
+  assertIteratorResult([0, 'a'], false, iterator.next());
+  assertIteratorResult([1, 'b'], false, iterator.next());
+  assertIteratorResult([2, 'c'], false, iterator.next());
   assertIteratorResult(void 0, true, iterator.next());
 
   array.push('d');
@@ -108,11 +108,11 @@ TestEntries();
 function TestEntriesMutate() {
   var array = ['a', 'b', 'c'];
   var iterator = array.entries();
-  assertIteratorResult(['0', 'a'], false, iterator.next());
-  assertIteratorResult(['1', 'b'], false, iterator.next());
-  assertIteratorResult(['2', 'c'], false, iterator.next());
+  assertIteratorResult([0, 'a'], false, iterator.next());
+  assertIteratorResult([1, 'b'], false, iterator.next());
+  assertIteratorResult([2, 'c'], false, iterator.next());
   array.push('d');
-  assertIteratorResult(['3', 'd'], false, iterator.next());
+  assertIteratorResult([3, 'd'], false, iterator.next());
   assertIteratorResult(void 0, true, iterator.next());
 }
 TestEntriesMutate();
@@ -168,7 +168,7 @@ function TestForArrayKeys() {
   assertEquals(8, buffer.length);
 
   for (var i = 0; i < buffer.length; i++) {
-    assertEquals(String(i), buffer[i]);
+    assertEquals(i, buffer[i]);
   }
 }
 TestForArrayKeys();
@@ -189,7 +189,7 @@ function TestForArrayEntries() {
   assertTrue(isNaN(buffer[buffer.length - 1][1]));
 
   for (var i = 0; i < buffer.length; i++) {
-    assertEquals(String(i), buffer[i][0]);
+    assertEquals(i, buffer[i][0]);
   }
 }
 TestForArrayEntries();