2 // https://github.com/tc39/proposal-iterator-helpers
3 var $ = require('../internals/export');
4 var apply = require('../internals/function-apply');
5 var anObject = require('../internals/an-object');
6 var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
8 var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise, args) {
10 var iterator = state.iterator;
12 return Promise.resolve(anObject(apply(state.next, iterator, args))).then(function (step) {
13 if (anObject(step).done) {
15 return { done: true, value: undefined };
17 return { done: false, value: [state.index++, step.value] };
21 $({ target: 'AsyncIterator', proto: true, real: true }, {
22 asIndexedPairs: function asIndexedPairs() {
23 return new AsyncIteratorProxy({
24 iterator: anObject(this),