from.js 3.6 KB

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  1. 'use strict';
  2. function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }
  3. function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }
  4. function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
  5. function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
  6. function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
  7. function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
  8. function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
  9. var ERR_INVALID_ARG_TYPE = require('../../../errors').codes.ERR_INVALID_ARG_TYPE;
  10. function from(Readable, iterable, opts) {
  11. var iterator;
  12. if (iterable && typeof iterable.next === 'function') {
  13. iterator = iterable;
  14. } else if (iterable && iterable[Symbol.asyncIterator]) iterator = iterable[Symbol.asyncIterator]();else if (iterable && iterable[Symbol.iterator]) iterator = iterable[Symbol.iterator]();else throw new ERR_INVALID_ARG_TYPE('iterable', ['Iterable'], iterable);
  15. var readable = new Readable(_objectSpread({
  16. objectMode: true
  17. }, opts));
  18. // Reading boolean to protect against _read
  19. // being called before last iteration completion.
  20. var reading = false;
  21. readable._read = function () {
  22. if (!reading) {
  23. reading = true;
  24. next();
  25. }
  26. };
  27. function next() {
  28. return _next2.apply(this, arguments);
  29. }
  30. function _next2() {
  31. _next2 = _asyncToGenerator(function* () {
  32. try {
  33. var _yield$iterator$next = yield iterator.next(),
  34. value = _yield$iterator$next.value,
  35. done = _yield$iterator$next.done;
  36. if (done) {
  37. readable.push(null);
  38. } else if (readable.push(yield value)) {
  39. next();
  40. } else {
  41. reading = false;
  42. }
  43. } catch (err) {
  44. readable.destroy(err);
  45. }
  46. });
  47. return _next2.apply(this, arguments);
  48. }
  49. return readable;
  50. }
  51. module.exports = from;