1 | 'use strict';
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2 | // https://github.com/tc39/proposal-iterator-helpers
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3 | var $ = require('../internals/export');
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4 | var aFunction = require('../internals/a-function');
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5 | var anObject = require('../internals/an-object');
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6 | var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
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7 | var getAsyncIteratorMethod = require('../internals/get-async-iterator-method');
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8 |
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9 | var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) {
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10 | var state = this;
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11 | var mapper = state.mapper;
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12 | var innerIterator, iteratorMethod;
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13 |
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14 | return new Promise(function (resolve, reject) {
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15 | var outerLoop = function () {
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16 | try {
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17 | Promise.resolve(anObject(state.next.call(state.iterator, arg))).then(function (step) {
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18 | try {
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19 | if (anObject(step).done) {
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20 | state.done = true;
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21 | resolve({ done: true, value: undefined });
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22 | } else {
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23 | Promise.resolve(mapper(step.value)).then(function (mapped) {
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24 | try {
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25 | iteratorMethod = getAsyncIteratorMethod(mapped);
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26 | if (iteratorMethod !== undefined) {
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27 | state.innerIterator = innerIterator = anObject(iteratorMethod.call(mapped));
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28 | state.innerNext = aFunction(innerIterator.next);
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29 | return innerLoop();
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30 | } reject(TypeError('.flatMap callback should return an iterable object'));
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31 | } catch (error2) { reject(error2); }
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32 | }, reject);
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33 | }
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34 | } catch (error1) { reject(error1); }
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35 | }, reject);
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36 | } catch (error) { reject(error); }
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37 | };
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38 |
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39 | var innerLoop = function () {
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40 | if (innerIterator = state.innerIterator) {
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41 | try {
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42 | Promise.resolve(anObject(state.innerNext.call(innerIterator))).then(function (result) {
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43 | try {
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44 | if (anObject(result).done) {
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45 | state.innerIterator = state.innerNext = null;
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46 | outerLoop();
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47 | } else resolve({ done: false, value: result.value });
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48 | } catch (error1) { reject(error1); }
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49 | }, reject);
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50 | } catch (error) { reject(error); }
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51 | } else outerLoop();
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52 | };
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53 |
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54 | innerLoop();
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55 | });
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56 | });
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57 |
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58 | $({ target: 'AsyncIterator', proto: true, real: true }, {
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59 | flatMap: function flatMap(mapper) {
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60 | return new AsyncIteratorProxy({
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61 | iterator: anObject(this),
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62 | mapper: aFunction(mapper),
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63 | innerIterator: null,
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64 | innerNext: null
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65 | });
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66 | }
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67 | });
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