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- 'use strict';
- // https://github.com/tc39/proposal-iterator-helpers
- var $ = require('../internals/export');
- var call = require('../internals/function-call');
- var aCallable = require('../internals/a-callable');
- var anObject = require('../internals/an-object');
- var isObject = require('../internals/is-object');
- var getIteratorDirect = require('../internals/get-iterator-direct');
- var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
- var createIterResultObject = require('../internals/create-iter-result-object');
- var closeAsyncIteration = require('../internals/async-iterator-close');
- var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) {
- var state = this;
- var iterator = state.iterator;
- var mapper = state.mapper;
- return new Promise(function (resolve, reject) {
- var doneAndReject = function (error) {
- state.done = true;
- reject(error);
- };
- var ifAbruptCloseAsyncIterator = function (error) {
- closeAsyncIteration(iterator, doneAndReject, error, doneAndReject);
- };
- Promise.resolve(anObject(call(state.next, iterator))).then(function (step) {
- try {
- if (anObject(step).done) {
- state.done = true;
- resolve(createIterResultObject(undefined, true));
- } else {
- var value = step.value;
- try {
- var result = mapper(value, state.counter++);
- var handler = function (mapped) {
- resolve(createIterResultObject(mapped, false));
- };
- if (isObject(result)) Promise.resolve(result).then(handler, ifAbruptCloseAsyncIterator);
- else handler(result);
- } catch (error2) { ifAbruptCloseAsyncIterator(error2); }
- }
- } catch (error) { doneAndReject(error); }
- }, doneAndReject);
- });
- });
- $({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
- map: function map(mapper) {
- return new AsyncIteratorProxy(getIteratorDirect(this), {
- mapper: aCallable(mapper)
- });
- }
- });
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