2 // https://github.com/tc39/proposal-iterator-helpers
3 var $ = require('../internals/export');
4 var anObject = require('../internals/an-object');
5 var toPositiveInteger = require('../internals/to-positive-integer');
6 var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
8 var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) {
11 return new Promise(function (resolve, reject) {
12 var loop = function () {
15 anObject(state.next.call(state.iterator, state.remaining ? undefined : arg))
16 ).then(function (step) {
18 if (anObject(step).done) {
20 resolve({ done: true, value: undefined });
21 } else if (state.remaining) {
24 } else resolve({ done: false, value: step.value });
25 } catch (err) { reject(err); }
27 } catch (error) { reject(error); }
34 $({ target: 'AsyncIterator', proto: true, real: true }, {
35 drop: function drop(limit) {
36 return new AsyncIteratorProxy({
37 iterator: anObject(this),
38 remaining: toPositiveInteger(limit)