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65 lines
2.2 KiB
65 lines
2.2 KiB
'use strict'; |
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// https://github.com/tc39/proposal-iterator-helpers |
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var $ = require('../internals/export'); |
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var call = require('../internals/function-call'); |
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var aCallable = require('../internals/a-callable'); |
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var anObject = require('../internals/an-object'); |
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var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy'); |
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var getAsyncIterator = require('../internals/get-async-iterator'); |
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var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) { |
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var state = this; |
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var mapper = state.mapper; |
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var innerIterator; |
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return new Promise(function (resolve, reject) { |
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var outerLoop = function () { |
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try { |
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Promise.resolve(anObject(call(state.next, state.iterator))).then(function (step) { |
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try { |
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if (anObject(step).done) { |
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state.done = true; |
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resolve({ done: true, value: undefined }); |
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} else { |
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Promise.resolve(mapper(step.value)).then(function (mapped) { |
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try { |
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state.innerIterator = innerIterator = getAsyncIterator(mapped); |
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state.innerNext = aCallable(innerIterator.next); |
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return innerLoop(); |
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} catch (error2) { reject(error2); } |
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}, reject); |
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} |
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} catch (error1) { reject(error1); } |
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}, reject); |
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} catch (error) { reject(error); } |
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}; |
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var innerLoop = function () { |
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if (innerIterator = state.innerIterator) { |
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try { |
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Promise.resolve(anObject(call(state.innerNext, innerIterator))).then(function (result) { |
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try { |
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if (anObject(result).done) { |
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state.innerIterator = state.innerNext = null; |
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outerLoop(); |
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} else resolve({ done: false, value: result.value }); |
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} catch (error1) { reject(error1); } |
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}, reject); |
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} catch (error) { reject(error); } |
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} else outerLoop(); |
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}; |
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innerLoop(); |
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}); |
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}); |
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$({ target: 'AsyncIterator', proto: true, real: true, forced: true }, { |
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flatMap: function flatMap(mapper) { |
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return new AsyncIteratorProxy({ |
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iterator: anObject(this), |
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mapper: aCallable(mapper), |
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innerIterator: null, |
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innerNext: null |
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}); |
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} |
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});
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