es.iterator.map.js 1.9 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var call = require('../internals/function-call');
  4. var aCallable = require('../internals/a-callable');
  5. var anObject = require('../internals/an-object');
  6. var getIteratorDirect = require('../internals/get-iterator-direct');
  7. var createIteratorProxy = require('../internals/iterator-create-proxy');
  8. var callWithSafeIterationClosing = require('../internals/call-with-safe-iteration-closing');
  9. var iteratorClose = require('../internals/iterator-close');
  10. var iteratorHelperThrowsOnInvalidIterator = require('../internals/iterator-helper-throws-on-invalid-iterator');
  11. var iteratorHelperWithoutClosingOnEarlyError = require('../internals/iterator-helper-without-closing-on-early-error');
  12. var IS_PURE = require('../internals/is-pure');
  13. var MAP_WITHOUT_THROWING_ON_INVALID_ITERATOR = !IS_PURE && !iteratorHelperThrowsOnInvalidIterator('map', function () { /* empty */ });
  14. var mapWithoutClosingOnEarlyError = !IS_PURE && !MAP_WITHOUT_THROWING_ON_INVALID_ITERATOR
  15. && iteratorHelperWithoutClosingOnEarlyError('map', TypeError);
  16. var FORCED = IS_PURE || MAP_WITHOUT_THROWING_ON_INVALID_ITERATOR || mapWithoutClosingOnEarlyError;
  17. var IteratorProxy = createIteratorProxy(function () {
  18. var iterator = this.iterator;
  19. var result = anObject(call(this.next, iterator));
  20. var done = this.done = !!result.done;
  21. if (!done) return callWithSafeIterationClosing(iterator, this.mapper, [result.value, this.counter++], true);
  22. });
  23. // `Iterator.prototype.map` method
  24. // https://tc39.es/ecma262/#sec-iterator.prototype.map
  25. $({ target: 'Iterator', proto: true, real: true, forced: FORCED }, {
  26. map: function map(mapper) {
  27. anObject(this);
  28. try {
  29. aCallable(mapper);
  30. } catch (error) {
  31. iteratorClose(this, 'throw', error);
  32. }
  33. if (mapWithoutClosingOnEarlyError) return call(mapWithoutClosingOnEarlyError, this, mapper);
  34. return new IteratorProxy(getIteratorDirect(this), {
  35. mapper: mapper
  36. });
  37. }
  38. });