v8/src/harmony-array-includes.js

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// Copyright 2014 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();
var GlobalArray = global.Array;
// -------------------------------------------------------------------
// Proposed for ES7
// https://github.com/tc39/Array.prototype.includes
// 6e3b78c927aeda20b9d40e81303f9d44596cd904
function ArrayIncludes(searchElement, fromIndex) {
var array = $toObject(this);
var len = $toLength(array.length);
if (len === 0) {
return false;
}
var n = $toInteger(fromIndex);
var k;
if (n >= 0) {
k = n;
} else {
k = len + n;
if (k < 0) {
k = 0;
}
}
while (k < len) {
var elementK = array[k];
if ($sameValueZero(searchElement, elementK)) {
return true;
}
++k;
}
return false;
}
// -------------------------------------------------------------------
%FunctionSetLength(ArrayIncludes, 1);
// Set up the non-enumerable functions on the Array prototype object.
$installFunctions(GlobalArray.prototype, DONT_ENUM, [
"includes", ArrayIncludes
]);
})