1 // https://github.com/tc39/proposal-iterator-helpers
2 var $ = require('../internals/export');
3 var path = require('../internals/path');
4 var aFunction = require('../internals/a-function');
5 var anObject = require('../internals/an-object');
6 var toObject = require('../internals/to-object');
7 var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
8 var getAsyncIteratorMethod = require('../internals/get-async-iterator-method');
10 var AsyncIterator = path.AsyncIterator;
12 var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg) {
13 return anObject(this.next.call(this.iterator, arg));
16 $({ target: 'AsyncIterator', stat: true }, {
17 from: function from(O) {
18 var object = toObject(O);
19 var usingIterator = getAsyncIteratorMethod(object);
21 if (usingIterator != null) {
22 iterator = aFunction(usingIterator).call(object);
23 if (iterator instanceof AsyncIterator) return iterator;
26 } return new AsyncIteratorProxy({