305 lines
7.4 KiB
JavaScript
305 lines
7.4 KiB
JavaScript
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'use strict';
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var _assign = require('object-assign');
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function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
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/**
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* Copyright (c) 2013-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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*
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*/
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var KIND_KEYS = 'keys';
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var KIND_VALUES = 'values';
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var KIND_ENTRIES = 'entries';
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/**
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* Specific Array iterators.
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*/
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var ArrayIterators = function () {
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var hasNative = hasNativeIterator(Array);
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var ArrayIterator = void 0;
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if (!hasNative) {
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ArrayIterator = function () {
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// 22.1.5.1 CreateArrayIterator Abstract Operation
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function ArrayIterator(array, kind) {
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_classCallCheck(this, ArrayIterator);
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this._iteratedObject = array;
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this._kind = kind;
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this._nextIndex = 0;
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}
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// 22.1.5.2.1 %ArrayIteratorPrototype%.next()
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ArrayIterator.prototype.next = function next() {
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if (this._iteratedObject == null) {
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return { value: undefined, done: true };
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}
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var array = this._iteratedObject;
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var len = this._iteratedObject.length;
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var index = this._nextIndex;
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var kind = this._kind;
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if (index >= len) {
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this._iteratedObject = undefined;
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return { value: undefined, done: true };
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}
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this._nextIndex = index + 1;
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if (kind === KIND_KEYS) {
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return { value: index, done: false };
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} else if (kind === KIND_VALUES) {
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return { value: array[index], done: false };
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} else if (kind === KIND_ENTRIES) {
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return { value: [index, array[index]], done: false };
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}
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};
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// 22.1.5.2.2 %ArrayIteratorPrototype%[@@iterator]()
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ArrayIterator.prototype[Symbol.iterator] = function () {
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return this;
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};
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return ArrayIterator;
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}();
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}
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return {
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keys: hasNative ? function (array) {
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return array.keys();
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} : function (array) {
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return new ArrayIterator(array, KIND_KEYS);
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},
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values: hasNative ? function (array) {
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return array.values();
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} : function (array) {
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return new ArrayIterator(array, KIND_VALUES);
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},
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entries: hasNative ? function (array) {
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return array.entries();
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} : function (array) {
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return new ArrayIterator(array, KIND_ENTRIES);
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}
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};
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}();
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// -----------------------------------------------------------------
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/**
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* Specific String iterators.
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*/
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var StringIterators = function () {
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var hasNative = hasNativeIterator(String);
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var StringIterator = void 0;
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if (!hasNative) {
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StringIterator = function () {
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// 21.1.5.1 CreateStringIterator Abstract Operation
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function StringIterator(string) {
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_classCallCheck(this, StringIterator);
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this._iteratedString = string;
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this._nextIndex = 0;
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}
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// 21.1.5.2.1 %StringIteratorPrototype%.next()
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StringIterator.prototype.next = function next() {
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if (this._iteratedString == null) {
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return { value: undefined, done: true };
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}
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var index = this._nextIndex;
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var s = this._iteratedString;
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var len = s.length;
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if (index >= len) {
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this._iteratedString = undefined;
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return { value: undefined, done: true };
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}
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var ret = void 0;
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var first = s.charCodeAt(index);
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if (first < 0xD800 || first > 0xDBFF || index + 1 === len) {
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ret = s[index];
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} else {
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var second = s.charCodeAt(index + 1);
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if (second < 0xDC00 || second > 0xDFFF) {
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ret = s[index];
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} else {
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ret = s[index] + s[index + 1];
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}
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}
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this._nextIndex = index + ret.length;
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return { value: ret, done: false };
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};
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// 21.1.5.2.2 %StringIteratorPrototype%[@@iterator]()
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StringIterator.prototype[Symbol.iterator] = function () {
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return this;
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};
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return StringIterator;
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}();
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}
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return {
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keys: function keys() {
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throw TypeError('Strings default iterator doesn\'t implement keys.');
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},
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values: hasNative ? function (string) {
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return string[Symbol.iterator]();
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} : function (string) {
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return new StringIterator(string);
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},
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entries: function entries() {
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throw TypeError('Strings default iterator doesn\'t implement entries.');
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}
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};
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}();
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function hasNativeIterator(classObject) {
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return typeof classObject.prototype[Symbol.iterator] === 'function' && typeof classObject.prototype.values === 'function' && typeof classObject.prototype.keys === 'function' && typeof classObject.prototype.entries === 'function';
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}
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// -----------------------------------------------------------------
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/**
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* Generic object iterator.
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*/
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var ObjectIterator = function () {
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function ObjectIterator(object, kind) {
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_classCallCheck(this, ObjectIterator);
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this._iteratedObject = object;
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this._kind = kind;
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this._keys = Object.keys(object);
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this._nextIndex = 0;
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}
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ObjectIterator.prototype.next = function next() {
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var len = this._keys.length;
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var index = this._nextIndex;
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var kind = this._kind;
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var key = this._keys[index];
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if (index >= len) {
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this._iteratedObject = undefined;
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return { value: undefined, done: true };
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}
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this._nextIndex = index + 1;
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if (kind === KIND_KEYS) {
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return { value: key, done: false };
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} else if (kind === KIND_VALUES) {
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return { value: this._iteratedObject[key], done: false };
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} else if (kind === KIND_ENTRIES) {
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return { value: [key, this._iteratedObject[key]], done: false };
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}
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};
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ObjectIterator.prototype[Symbol.iterator] = function () {
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return this;
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};
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return ObjectIterator;
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}();
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/**
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* Generic object iterator, iterates over all own enumerable
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* properties. Used only if if no specific iterator is available,
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* and object don't implement iterator protocol.
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*/
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var GenericIterators = {
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keys: function keys(object) {
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return new ObjectIterator(object, KIND_KEYS);
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},
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values: function values(object) {
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return new ObjectIterator(object, KIND_VALUES);
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},
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entries: function entries(object) {
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return new ObjectIterator(object, KIND_ENTRIES);
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}
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};
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// -----------------------------------------------------------------
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/**
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* Main iterator function. Returns default iterator based
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* on the class of an instance.
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*/
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function enumerate(object, kind) {
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// First check specific iterators.
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if (typeof object === 'string') {
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return StringIterators[kind || KIND_VALUES](object);
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} else if (Array.isArray(object)) {
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return ArrayIterators[kind || KIND_VALUES](object);
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// Then see if an object implements own.
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} else if (object[Symbol.iterator]) {
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return object[Symbol.iterator]();
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// And fallback to generic with entries.
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} else {
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return GenericIterators[kind || KIND_ENTRIES](object);
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}
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}
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_assign(enumerate, {
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/**
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* Export constants
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*/
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KIND_KEYS: KIND_KEYS,
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KIND_VALUES: KIND_VALUES,
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KIND_ENTRIES: KIND_ENTRIES,
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/**
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* Convenient explicit iterators for special kinds.
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*/
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keys: function keys(object) {
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return enumerate(object, KIND_KEYS);
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},
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values: function values(object) {
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return enumerate(object, KIND_VALUES);
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},
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entries: function entries(object) {
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return enumerate(object, KIND_ENTRIES);
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},
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generic: GenericIterators.entries
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});
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module.exports = enumerate;
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