| 'use strict'; |
| // https://github.com/tc39/proposal-iterator-helpers |
| var $ = require('../internals/export'); |
| var anObject = require('../internals/an-object'); |
| var toPositiveInteger = require('../internals/to-positive-integer'); |
| var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy'); |
| |
| var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) { |
| var iterator = this.iterator; |
| var returnMethod, result; |
| if (!this.remaining--) { |
| result = { done: true, value: undefined }; |
| this.done = true; |
| returnMethod = iterator['return']; |
| if (returnMethod !== undefined) { |
| return Promise.resolve(returnMethod.call(iterator)).then(function () { |
| return result; |
| }); |
| } |
| return result; |
| } return this.next.call(iterator, arg); |
| }); |
| |
| $({ target: 'AsyncIterator', proto: true, real: true }, { |
| take: function take(limit) { |
| return new AsyncIteratorProxy({ |
| iterator: anObject(this), |
| remaining: toPositiveInteger(limit) |
| }); |
| } |
| }); |