UNPKG

1.21 kBJavaScriptView Raw
1'use strict';
2var $ = require('../internals/export');
3var call = require('../internals/function-call');
4var anObject = require('../internals/an-object');
5var getIteratorDirect = require('../internals/get-iterator-direct');
6var notANaN = require('../internals/not-a-nan');
7var toPositiveInteger = require('../internals/to-positive-integer');
8var createIteratorProxy = require('../internals/iterator-create-proxy');
9var iteratorClose = require('../internals/iterator-close');
10var IS_PURE = require('../internals/is-pure');
11
12var IteratorProxy = createIteratorProxy(function () {
13 var iterator = this.iterator;
14 if (!this.remaining--) {
15 this.done = true;
16 return iteratorClose(iterator, 'normal', undefined);
17 }
18 var result = anObject(call(this.next, iterator));
19 var done = this.done = !!result.done;
20 if (!done) return result.value;
21});
22
23// `Iterator.prototype.take` method
24// https://github.com/tc39/proposal-iterator-helpers
25$({ target: 'Iterator', proto: true, real: true, forced: IS_PURE }, {
26 take: function take(limit) {
27 anObject(this);
28 var remaining = toPositiveInteger(notANaN(+limit));
29 return new IteratorProxy(getIteratorDirect(this), {
30 remaining: remaining
31 });
32 }
33});