106 lines
4.2 KiB
JavaScript
106 lines
4.2 KiB
JavaScript
'use strict';
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var call = require('../internals/function-call');
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var perform = require('../internals/perform');
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var anObject = require('../internals/an-object');
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var create = require('../internals/object-create');
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var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
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var defineBuiltIns = require('../internals/define-built-ins');
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var wellKnownSymbol = require('../internals/well-known-symbol');
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var InternalStateModule = require('../internals/internal-state');
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var getBuiltIn = require('../internals/get-built-in');
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var getMethod = require('../internals/get-method');
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var AsyncIteratorPrototype = require('../internals/async-iterator-prototype');
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var createIterResultObject = require('../internals/create-iter-result-object');
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var iteratorClose = require('../internals/iterator-close');
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var Promise = getBuiltIn('Promise');
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var TO_STRING_TAG = wellKnownSymbol('toStringTag');
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var ASYNC_ITERATOR_HELPER = 'AsyncIteratorHelper';
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var WRAP_FOR_VALID_ASYNC_ITERATOR = 'WrapForValidAsyncIterator';
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var setInternalState = InternalStateModule.set;
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var createAsyncIteratorProxyPrototype = function (IS_ITERATOR) {
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var IS_GENERATOR = !IS_ITERATOR;
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var getInternalState = InternalStateModule.getterFor(IS_ITERATOR ? WRAP_FOR_VALID_ASYNC_ITERATOR : ASYNC_ITERATOR_HELPER);
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var getStateOrEarlyExit = function (that) {
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var stateCompletion = perform(function () {
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return getInternalState(that);
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});
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var stateError = stateCompletion.error;
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var state = stateCompletion.value;
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if (stateError || (IS_GENERATOR && state.done)) {
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return { exit: true, value: stateError ? Promise.reject(state) : Promise.resolve(createIterResultObject(undefined, true)) };
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} return { exit: false, value: state };
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};
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return defineBuiltIns(create(AsyncIteratorPrototype), {
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next: function next() {
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var stateCompletion = getStateOrEarlyExit(this);
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var state = stateCompletion.value;
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if (stateCompletion.exit) return state;
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var handlerCompletion = perform(function () {
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return anObject(state.nextHandler(Promise));
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});
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var handlerError = handlerCompletion.error;
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var value = handlerCompletion.value;
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if (handlerError) state.done = true;
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return handlerError ? Promise.reject(value) : Promise.resolve(value);
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},
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'return': function () {
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var stateCompletion = getStateOrEarlyExit(this);
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var state = stateCompletion.value;
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if (stateCompletion.exit) return state;
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state.done = true;
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var iterator = state.iterator;
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var returnMethod, result;
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var completion = perform(function () {
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if (state.inner) try {
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iteratorClose(state.inner.iterator, 'normal');
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} catch (error) {
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return iteratorClose(iterator, 'throw', error);
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}
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return getMethod(iterator, 'return');
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});
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returnMethod = result = completion.value;
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if (completion.error) return Promise.reject(result);
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if (returnMethod === undefined) return Promise.resolve(createIterResultObject(undefined, true));
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completion = perform(function () {
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return call(returnMethod, iterator);
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});
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result = completion.value;
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if (completion.error) return Promise.reject(result);
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return IS_ITERATOR ? Promise.resolve(result) : Promise.resolve(result).then(function (resolved) {
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anObject(resolved);
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return createIterResultObject(undefined, true);
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});
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}
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});
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};
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var WrapForValidAsyncIteratorPrototype = createAsyncIteratorProxyPrototype(true);
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var AsyncIteratorHelperPrototype = createAsyncIteratorProxyPrototype(false);
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createNonEnumerableProperty(AsyncIteratorHelperPrototype, TO_STRING_TAG, 'Async Iterator Helper');
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module.exports = function (nextHandler, IS_ITERATOR) {
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var AsyncIteratorProxy = function AsyncIterator(record, state) {
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if (state) {
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state.iterator = record.iterator;
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state.next = record.next;
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} else state = record;
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state.type = IS_ITERATOR ? WRAP_FOR_VALID_ASYNC_ITERATOR : ASYNC_ITERATOR_HELPER;
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state.nextHandler = nextHandler;
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state.counter = 0;
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state.done = false;
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setInternalState(this, state);
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};
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AsyncIteratorProxy.prototype = IS_ITERATOR ? WrapForValidAsyncIteratorPrototype : AsyncIteratorHelperPrototype;
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return AsyncIteratorProxy;
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};
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