1 | import {
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2 | isArray,
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3 | isMaybeThenable
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4 | } from './utils';
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5 | import {
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6 | noop,
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7 | reject,
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8 | fulfill,
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9 | subscribe,
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10 | FULFILLED,
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11 | REJECTED,
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12 | PENDING,
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13 | getThen,
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14 | handleMaybeThenable
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15 | } from './-internal';
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16 |
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17 | import then from './then';
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18 | import Promise from './promise';
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19 | import originalResolve from './promise/resolve';
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20 | import originalThen from './then';
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21 | import { makePromise, PROMISE_ID } from './-internal';
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22 |
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23 | function validationError() {
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24 | return new Error('Array Methods must be provided an Array');
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25 | };
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26 |
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27 | export default class Enumerator {
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28 | constructor(Constructor, input) {
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29 | this._instanceConstructor = Constructor;
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30 | this.promise = new Constructor(noop);
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31 |
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32 | if (!this.promise[PROMISE_ID]) {
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33 | makePromise(this.promise);
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34 | }
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35 |
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36 | if (isArray(input)) {
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37 | this.length = input.length;
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38 | this._remaining = input.length;
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39 |
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40 | this._result = new Array(this.length);
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41 |
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42 | if (this.length === 0) {
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43 | fulfill(this.promise, this._result);
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44 | } else {
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45 | this.length = this.length || 0;
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46 | this._enumerate(input);
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47 | if (this._remaining === 0) {
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48 | fulfill(this.promise, this._result);
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49 | }
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50 | }
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51 | } else {
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52 | reject(this.promise, validationError());
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53 | }
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54 | }
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55 | _enumerate(input) {
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56 | for (let i = 0; this._state === PENDING && i < input.length; i++) {
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57 | this._eachEntry(input[i], i);
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58 | }
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59 | }
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60 |
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61 | _eachEntry(entry, i) {
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62 | let c = this._instanceConstructor;
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63 | let { resolve } = c;
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64 |
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65 | if (resolve === originalResolve) {
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66 | let then = getThen(entry);
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67 |
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68 | if (then === originalThen &&
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69 | entry._state !== PENDING) {
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70 | this._settledAt(entry._state, i, entry._result);
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71 | } else if (typeof then !== 'function') {
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72 | this._remaining--;
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73 | this._result[i] = entry;
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74 | } else if (c === Promise) {
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75 | let promise = new c(noop);
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76 | handleMaybeThenable(promise, entry, then);
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77 | this._willSettleAt(promise, i);
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78 | } else {
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79 | this._willSettleAt(new c(resolve => resolve(entry)), i);
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80 | }
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81 | } else {
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82 | this._willSettleAt(resolve(entry), i);
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83 | }
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84 | }
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85 |
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86 | _settledAt(state, i, value) {
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87 | let { promise } = this;
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88 |
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89 | if (promise._state === PENDING) {
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90 | this._remaining--;
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91 |
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92 | if (state === REJECTED) {
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93 | reject(promise, value);
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94 | } else {
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95 | this._result[i] = value;
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96 | }
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97 | }
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98 |
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99 | if (this._remaining === 0) {
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100 | fulfill(promise, this._result);
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101 | }
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102 | }
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103 |
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104 | _willSettleAt(promise, i) {
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105 | let enumerator = this;
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106 |
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107 | subscribe(
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108 | promise, undefined,
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109 | value => enumerator._settledAt(FULFILLED, i, value),
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110 | reason => enumerator._settledAt(REJECTED, i, reason)
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111 | );
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112 | }
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113 | };
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