'use strict';

var $ = require('../internals/export');

var globalThis = require('../internals/global-this');

var anInstance = require('../internals/an-instance');

var anObject = require('../internals/an-object');

var isCallable = require('../internals/is-callable');

var getPrototypeOf = require('../internals/object-get-prototype-of');

var defineBuiltInAccessor = require('../internals/define-built-in-accessor');

var createProperty = require('../internals/create-property');

var fails = require('../internals/fails');

var hasOwn = require('../internals/has-own-property');

var wellKnownSymbol = require('../internals/well-known-symbol');

var IteratorPrototype = require('../internals/iterators-core').IteratorPrototype;

var DESCRIPTORS = require('../internals/descriptors');

var IS_PURE = require('../internals/is-pure');

var CONSTRUCTOR = 'constructor';

var ITERATOR = 'Iterator';

var TO_STRING_TAG = wellKnownSymbol('toStringTag');

var $TypeError = TypeError;

var NativeIterator = globalThis[ITERATOR];

// FF56- have non-standard global helper `Iterator`

var FORCED = IS_PURE

|| !isCallable(NativeIterator)

|| NativeIterator.prototype !== IteratorPrototype

// FF44- non-standard `Iterator` passes previous tests

|| !fails(function () { NativeIterator({}); });

var IteratorConstructor = function Iterator() {

anInstance(this, IteratorPrototype);

if (getPrototypeOf(this) === IteratorPrototype) throw new $TypeError('Abstract class Iterator not directly constructable');

};

var defineIteratorPrototypeAccessor = function (key, value) {

};

if (!hasOwn(IteratorPrototype, TO_STRING_TAG)) defineIteratorPrototypeAccessor(TO_STRING_TAG, ITERATOR);

if (FORCED || !hasOwn(IteratorPrototype, CONSTRUCTOR) || IteratorPrototype[CONSTRUCTOR] === Object) {

defineIteratorPrototypeAccessor(CONSTRUCTOR, IteratorConstructor);

}

IteratorConstructor.prototype = IteratorPrototype;

// `Iterator` constructor

// https://tc39.es/ecma262/#sec-iterator

$({ global: true, constructor: true, forced: FORCED }, {

Iterator: IteratorConstructor

});