102 lines
3.3 KiB
JavaScript
102 lines
3.3 KiB
JavaScript
'use strict';
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var $TypeError = require('es-errors/type');
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var AdvanceStringIndex = require('es-abstract/2024/AdvanceStringIndex');
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var Call = require('es-abstract/2024/Call');
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var CompletionRecord = require('es-abstract/2024/CompletionRecord');
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var CreateIteratorFromClosure = require('../aos/CreateIteratorFromClosure');
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var GetIteratorDirect = require('../aos/GetIteratorDirect');
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var GetMethod = require('es-abstract/2024/GetMethod');
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var IsArray = require('es-abstract/2024/IsArray');
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var IteratorCloseAll = require('../aos/IteratorCloseAll');
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var IteratorStepValue = require('es-abstract/2024/IteratorStepValue');
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var Type = require('es-abstract/2024/Type');
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var forEach = require('es-abstract/helpers/forEach');
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var getIteratorMethod = require('es-abstract/helpers/getIteratorMethod');
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var iterHelperProto = require('../IteratorHelperPrototype');
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var SLOT = require('internal-slot');
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module.exports = function concat() {
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if (this instanceof concat) {
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throw new $TypeError('`Iterator.concat` is not a constructor');
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}
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var iterables = []; // step 1
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forEach(arguments, function (item) { // step 2
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if (Type(item) !== 'Object') {
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throw new $TypeError('`Iterator.concat` requires all arguments to be objects'); // step 2.1
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}
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// var method = GetMethod(item, Symbol.iterator); // step 2.2
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var method = getIteratorMethod(
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{
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AdvanceStringIndex: AdvanceStringIndex,
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GetMethod: GetMethod,
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IsArray: IsArray
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},
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item
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);
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if (typeof method === 'undefined') {
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throw new $TypeError('`Iterator.concat` requires all arguments to be iterable'); // step 2.3
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}
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iterables[iterables.length] = { '[[OpenMethod]]': method, '[[Iterable]]': item }; // step 2.4
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});
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var sentinel = {};
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var iterablesIndex = 0;
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var iteratorRecord;
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var innerAlive = false;
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var closure = function () { // step 3
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if (iterablesIndex >= iterables.length) {
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return sentinel;
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}
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var iterable = iterables[iterablesIndex]; // step 3.a
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if (!innerAlive) {
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var iter = Call(iterable['[[OpenMethod]]'], iterable['[[Iterable]]']); // step 3.a.i
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if (Type(iter) !== 'Object') {
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throw new $TypeError('`Iterator.concat` iterator method did not return an object'); // step 3.a.ii
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}
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iteratorRecord = GetIteratorDirect(iter); // step 3.a.iii
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innerAlive = true; // step 3.a.iv
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}
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if (innerAlive) { // step 3.a.v
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var innerValue = IteratorStepValue(iteratorRecord); // step 3.a.v.1
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if (iteratorRecord['[[Done]]']) { // step 3.a.v.2
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innerAlive = false; // step 3.a.v.2.a
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} else { // step 3.a.v.3
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// 1. Let completion be Completion(Yield(innerValue)).
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return innerValue; // step 3.a.v.3.a
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}
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}
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iterablesIndex += 1;
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return closure();
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};
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var closeIfAbrupt = function (abruptCompletion) {
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if (!(abruptCompletion instanceof CompletionRecord)) {
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throw new $TypeError('`abruptCompletion` must be a Completion Record');
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}
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iterablesIndex = iterables.length;
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innerAlive = false;
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if (iteratorRecord) {
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IteratorCloseAll(
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[iteratorRecord],
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abruptCompletion
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);
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}
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};
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SLOT.set(closure, '[[Sentinel]]', sentinel); // for the userland implementation
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SLOT.set(closure, '[[CloseIfAbrupt]]', closeIfAbrupt); // for the userland implementation
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var gen = CreateIteratorFromClosure(closure, 'Iterator Helper', iterHelperProto, ['[[UnderlyingIterators]]']); // step 5
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SLOT.set(gen, '[[UnderlyingIterators]]', []); // step 6
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return gen; // step 7
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};
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