esnext.iterator.take.js 1.0 KB

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  1. 'use strict';
  2. // https://github.com/tc39/proposal-iterator-helpers
  3. var $ = require('../internals/export');
  4. var apply = require('../internals/function-apply');
  5. var anObject = require('../internals/an-object');
  6. var getIteratorDirect = require('../internals/get-iterator-direct');
  7. var toPositiveInteger = require('../internals/to-positive-integer');
  8. var createIteratorProxy = require('../internals/iterator-create-proxy');
  9. var iteratorClose = require('../internals/iterator-close');
  10. var IteratorProxy = createIteratorProxy(function (args) {
  11. var iterator = this.iterator;
  12. if (!this.remaining--) {
  13. this.done = true;
  14. return iteratorClose(iterator, 'normal', undefined);
  15. }
  16. var result = anObject(apply(this.next, iterator, args));
  17. var done = this.done = !!result.done;
  18. if (!done) return result.value;
  19. });
  20. $({ target: 'Iterator', proto: true, real: true, forced: true }, {
  21. take: function take(limit) {
  22. return new IteratorProxy(getIteratorDirect(this), {
  23. remaining: toPositiveInteger(limit)
  24. });
  25. }
  26. });