--- /dev/null
+'use strict';
+// https://github.com/tc39/proposal-iterator-helpers
+var $ = require('../internals/export');
+var anObject = require('../internals/an-object');
+var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
+
+var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) {
+ var state = this;
+ var iterator = state.iterator;
+
+ return Promise.resolve(anObject(state.next.call(iterator, arg))).then(function (step) {
+ if (anObject(step).done) {
+ state.done = true;
+ return { done: true, value: undefined };
+ }
+ return { done: false, value: [state.index++, step.value] };
+ });
+});
+
+$({ target: 'AsyncIterator', proto: true, real: true }, {
+ asIndexedPairs: function asIndexedPairs() {
+ return new AsyncIteratorProxy({
+ iterator: anObject(this),
+ index: 0
+ });
+ }
+});