--- /dev/null
+'use strict';
+var $ = require('../internals/export');
+var createIteratorConstructor = require('../internals/create-iterator-constructor');
+var getPrototypeOf = require('../internals/object-get-prototype-of');
+var setPrototypeOf = require('../internals/object-set-prototype-of');
+var setToStringTag = require('../internals/set-to-string-tag');
+var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
+var redefine = require('../internals/redefine');
+var wellKnownSymbol = require('../internals/well-known-symbol');
+var IS_PURE = require('../internals/is-pure');
+var Iterators = require('../internals/iterators');
+var IteratorsCore = require('../internals/iterators-core');
+
+var IteratorPrototype = IteratorsCore.IteratorPrototype;
+var BUGGY_SAFARI_ITERATORS = IteratorsCore.BUGGY_SAFARI_ITERATORS;
+var ITERATOR = wellKnownSymbol('iterator');
+var KEYS = 'keys';
+var VALUES = 'values';
+var ENTRIES = 'entries';
+
+var returnThis = function () { return this; };
+
+module.exports = function (Iterable, NAME, IteratorConstructor, next, DEFAULT, IS_SET, FORCED) {
+ createIteratorConstructor(IteratorConstructor, NAME, next);
+
+ var getIterationMethod = function (KIND) {
+ if (KIND === DEFAULT && defaultIterator) return defaultIterator;
+ if (!BUGGY_SAFARI_ITERATORS && KIND in IterablePrototype) return IterablePrototype[KIND];
+ switch (KIND) {
+ case KEYS: return function keys() { return new IteratorConstructor(this, KIND); };
+ case VALUES: return function values() { return new IteratorConstructor(this, KIND); };
+ case ENTRIES: return function entries() { return new IteratorConstructor(this, KIND); };
+ } return function () { return new IteratorConstructor(this); };
+ };
+
+ var TO_STRING_TAG = NAME + ' Iterator';
+ var INCORRECT_VALUES_NAME = false;
+ var IterablePrototype = Iterable.prototype;
+ var nativeIterator = IterablePrototype[ITERATOR]
+ || IterablePrototype['@@iterator']
+ || DEFAULT && IterablePrototype[DEFAULT];
+ var defaultIterator = !BUGGY_SAFARI_ITERATORS && nativeIterator || getIterationMethod(DEFAULT);
+ var anyNativeIterator = NAME == 'Array' ? IterablePrototype.entries || nativeIterator : nativeIterator;
+ var CurrentIteratorPrototype, methods, KEY;
+
+ // fix native
+ if (anyNativeIterator) {
+ CurrentIteratorPrototype = getPrototypeOf(anyNativeIterator.call(new Iterable()));
+ if (IteratorPrototype !== Object.prototype && CurrentIteratorPrototype.next) {
+ if (!IS_PURE && getPrototypeOf(CurrentIteratorPrototype) !== IteratorPrototype) {
+ if (setPrototypeOf) {
+ setPrototypeOf(CurrentIteratorPrototype, IteratorPrototype);
+ } else if (typeof CurrentIteratorPrototype[ITERATOR] != 'function') {
+ createNonEnumerableProperty(CurrentIteratorPrototype, ITERATOR, returnThis);
+ }
+ }
+ // Set @@toStringTag to native iterators
+ setToStringTag(CurrentIteratorPrototype, TO_STRING_TAG, true, true);
+ if (IS_PURE) Iterators[TO_STRING_TAG] = returnThis;
+ }
+ }
+
+ // fix Array#{values, @@iterator}.name in V8 / FF
+ if (DEFAULT == VALUES && nativeIterator && nativeIterator.name !== VALUES) {
+ INCORRECT_VALUES_NAME = true;
+ defaultIterator = function values() { return nativeIterator.call(this); };
+ }
+
+ // define iterator
+ if ((!IS_PURE || FORCED) && IterablePrototype[ITERATOR] !== defaultIterator) {
+ createNonEnumerableProperty(IterablePrototype, ITERATOR, defaultIterator);
+ }
+ Iterators[NAME] = defaultIterator;
+
+ // export additional methods
+ if (DEFAULT) {
+ methods = {
+ values: getIterationMethod(VALUES),
+ keys: IS_SET ? defaultIterator : getIterationMethod(KEYS),
+ entries: getIterationMethod(ENTRIES)
+ };
+ if (FORCED) for (KEY in methods) {
+ if (BUGGY_SAFARI_ITERATORS || INCORRECT_VALUES_NAME || !(KEY in IterablePrototype)) {
+ redefine(IterablePrototype, KEY, methods[KEY]);
+ }
+ } else $({ target: NAME, proto: true, forced: BUGGY_SAFARI_ITERATORS || INCORRECT_VALUES_NAME }, methods);
+ }
+
+ return methods;
+};