CSE2410 Fall 2014 Bounce

// 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

//       with the distribution.

//     * Neither the name of Google Inc. nor the names of its

//       contributors may be used to endorse or promote products derived

//       from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// 'AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

'use strict';

// 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);

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;

  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];

  if (!array) {

    throw MakeTypeError('incompatible_method_receiver',

                        ['Array Iterator.prototype.next']);

  }

  var index = iterator[arrayIteratorNextIndexSymbol];

  var itemKind = iterator[arrayIterationKindSymbol];

  var length = TO_UINT32(array.length);

  // "sparse" is never used.

  if (index >= length) {

    iterator[arrayIteratorNextIndexSymbol] = 1 / 0; // Infinity

    return CreateIteratorResultObject(UNDEFINED, true);

  }

  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);

}

function ArrayEntries() {

  return CreateArrayIterator(this, ARRAY_ITERATOR_KIND_ENTRIES);

}

function ArrayValues() {

  return CreateArrayIterator(this, ARRAY_ITERATOR_KIND_VALUES);

}

function ArrayKeys() {

  return CreateArrayIterator(this, ARRAY_ITERATOR_KIND_KEYS);

}

function SetUpArrayIterator() {

  %CheckIsBootstrapping();

  %FunctionSetInstanceClassName(ArrayIterator, 'Array Iterator');

  %FunctionSetReadOnlyPrototype(ArrayIterator);

  InstallFunctions(ArrayIterator.prototype, DONT_ENUM, $Array(

    'next', ArrayIteratorNext

  ));

}

SetUpArrayIterator();

function ExtendArrayPrototype() {

  %CheckIsBootstrapping();

  InstallFunctions($Array.prototype, DONT_ENUM, $Array(

    'entries', ArrayEntries,

    'values', ArrayValues,

    'keys', ArrayKeys

  ));

}

ExtendArrayPrototype();