esnext.async-iterator.map.js 1.8 KB

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  1. 'use strict';
  2. // https://github.com/tc39/proposal-iterator-helpers
  3. var $ = require('../internals/export');
  4. var call = require('../internals/function-call');
  5. var aCallable = require('../internals/a-callable');
  6. var anObject = require('../internals/an-object');
  7. var getIteratorDirect = require('../internals/get-iterator-direct');
  8. var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
  9. var createIterResultObject = require('../internals/create-iter-result-object');
  10. var closeAsyncIteration = require('../internals/async-iterator-close');
  11. var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) {
  12. var state = this;
  13. var iterator = state.iterator;
  14. var mapper = state.mapper;
  15. return new Promise(function (resolve, reject) {
  16. var doneAndReject = function (error) {
  17. state.done = true;
  18. reject(error);
  19. };
  20. var ifAbruptCloseAsyncIterator = function (error) {
  21. closeAsyncIteration(iterator, doneAndReject, error, doneAndReject);
  22. };
  23. Promise.resolve(anObject(call(state.next, iterator))).then(function (step) {
  24. try {
  25. if (anObject(step).done) {
  26. state.done = true;
  27. resolve(createIterResultObject(undefined, true));
  28. } else {
  29. var value = step.value;
  30. try {
  31. Promise.resolve(mapper(value)).then(function (mapped) {
  32. resolve(createIterResultObject(mapped, false));
  33. }, ifAbruptCloseAsyncIterator);
  34. } catch (error2) { ifAbruptCloseAsyncIterator(error2); }
  35. }
  36. } catch (error) { doneAndReject(error); }
  37. }, doneAndReject);
  38. });
  39. });
  40. $({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
  41. map: function map(mapper) {
  42. return new AsyncIteratorProxy(getIteratorDirect(this), {
  43. mapper: aCallable(mapper)
  44. });
  45. }
  46. });