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- 'use strict';
- // https://github.com/tc39/proposal-iterator-helpers
- var $ = require('../internals/export');
- var aFunction = require('../internals/a-function');
- var anObject = require('../internals/an-object');
- var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
- var getAsyncIteratorMethod = require('../internals/get-async-iterator-method');
- var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) {
- var state = this;
- var mapper = state.mapper;
- var innerIterator, iteratorMethod;
- return new Promise(function (resolve, reject) {
- var outerLoop = function () {
- try {
- Promise.resolve(anObject(state.next.call(state.iterator, arg))).then(function (step) {
- try {
- if (anObject(step).done) {
- state.done = true;
- resolve({ done: true, value: undefined });
- } else {
- Promise.resolve(mapper(step.value)).then(function (mapped) {
- try {
- iteratorMethod = getAsyncIteratorMethod(mapped);
- if (iteratorMethod !== undefined) {
- state.innerIterator = innerIterator = anObject(iteratorMethod.call(mapped));
- state.innerNext = aFunction(innerIterator.next);
- return innerLoop();
- } reject(TypeError('.flatMap callback should return an iterable object'));
- } catch (error2) { reject(error2); }
- }, reject);
- }
- } catch (error1) { reject(error1); }
- }, reject);
- } catch (error) { reject(error); }
- };
- var innerLoop = function () {
- if (innerIterator = state.innerIterator) {
- try {
- Promise.resolve(anObject(state.innerNext.call(innerIterator))).then(function (result) {
- try {
- if (anObject(result).done) {
- state.innerIterator = state.innerNext = null;
- outerLoop();
- } else resolve({ done: false, value: result.value });
- } catch (error1) { reject(error1); }
- }, reject);
- } catch (error) { reject(error); }
- } else outerLoop();
- };
- innerLoop();
- });
- });
- $({ target: 'AsyncIterator', proto: true, real: true }, {
- flatMap: function flatMap(mapper) {
- return new AsyncIteratorProxy({
- iterator: anObject(this),
- mapper: aFunction(mapper),
- innerIterator: null,
- innerNext: null
- });
- }
- });
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