esnext.async-iterator.as-indexed-pairs.js 981 B

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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 createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
  8. var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise, args) {
  9. var state = this;
  10. var iterator = state.iterator;
  11. return Promise.resolve(anObject(apply(state.next, iterator, args))).then(function (step) {
  12. if (anObject(step).done) {
  13. state.done = true;
  14. return { done: true, value: undefined };
  15. }
  16. return { done: false, value: [state.index++, step.value] };
  17. });
  18. });
  19. $({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
  20. asIndexedPairs: function asIndexedPairs() {
  21. return new AsyncIteratorProxy(getIteratorDirect(this), {
  22. index: 0
  23. });
  24. }
  25. });