Provide private symbols through internal APIs

src/array-iterator.js

 // Copyright 2013 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 18 matching lines @@
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
 var ARRAY_ITERATOR_KIND_KEYS = 1;
 var ARRAY_ITERATOR_KIND_VALUES = 2;
 var ARRAY_ITERATOR_KIND_ENTRIES = 3;
 // The spec draft also has "sparse" but it is never used.
 
-var iteratorObjectSymbol = %CreateSymbol(UNDEFINED);
-var arrayIteratorNextIndexSymbol = %CreateSymbol(UNDEFINED);
-var arrayIterationKindSymbol = %CreateSymbol(UNDEFINED);
+var iteratorObjectSymbol = NEW_PRIVATE("iterator_object");
+var arrayIteratorNextIndexSymbol = NEW_PRIVATE("iterator_next");
+var arrayIterationKindSymbol = NEW_PRIVATE("iterator_kind");
 
 function ArrayIterator() {}
 
 // 15.4.5.1 CreateArrayIterator Abstract Operation
 function CreateArrayIterator(array, kind) {
   var object = ToObject(array);
   var iterator = new ArrayIterator;
-  iterator[iteratorObjectSymbol] = object;
-  iterator[arrayIteratorNextIndexSymbol] = 0;
-  iterator[arrayIterationKindSymbol] = kind;
+  SET_PRIVATE(iterator, iteratorObjectSymbol, object);
+  SET_PRIVATE(iterator, arrayIteratorNextIndexSymbol, 0);
+  SET_PRIVATE(iterator, arrayIterationKindSymbol, kind);
   return iterator;
 }
 
 // 15.19.4.3.4 CreateItrResultObject
 function CreateIteratorResultObject(value, done) {
   return {value: value, done: done};
 }
 
 // 15.4.5.2.2 ArrayIterator.prototype.next( )
 function ArrayIteratorNext() {
   var iterator = ToObject(this);
-  var array = iterator[iteratorObjectSymbol];
+  var array = GET_PRIVATE(iterator, iteratorObjectSymbol);
   if (!array) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Array Iterator.prototype.next']);
   }
 
-  var index = iterator[arrayIteratorNextIndexSymbol];
-  var itemKind = iterator[arrayIterationKindSymbol];
+  var index = GET_PRIVATE(iterator, arrayIteratorNextIndexSymbol);
+  var itemKind = GET_PRIVATE(iterator, arrayIterationKindSymbol);
   var length = TO_UINT32(array.length);
 
   // "sparse" is never used.
 
   if (index >= length) {
-    iterator[arrayIteratorNextIndexSymbol] = 1 / 0; // Infinity
+    SET_PRIVATE(iterator, arrayIteratorNextIndexSymbol, INFINITY);
     return CreateIteratorResultObject(UNDEFINED, true);
   }
 
-  iterator[arrayIteratorNextIndexSymbol] = index + 1;
+  SET_PRIVATE(iterator, arrayIteratorNextIndexSymbol, index + 1);
 
   if (itemKind == ARRAY_ITERATOR_KIND_VALUES)
     return CreateIteratorResultObject(array[index], false);
 
   if (itemKind == ARRAY_ITERATOR_KIND_ENTRIES)
     return CreateIteratorResultObject([index, array[index]], false);
 
   return CreateIteratorResultObject(index, false);
 }
 
@@ skipping 26 matching lines @@
   %CheckIsBootstrapping();
 
   InstallFunctions($Array.prototype, DONT_ENUM, $Array(
     'entries', ArrayEntries,
     'values', ArrayValues,
     'keys', ArrayKeys
   ));
 }
 
 ExtendArrayPrototype();