'use strict'; var $TypeError = require('es-errors/type'); var CreateIteratorFromClosure = require('./CreateIteratorFromClosure'); var IteratorCloseAll = require('./IteratorCloseAll'); var IteratorStep = require('es-abstract/2024/IteratorStep'); var IteratorStepValue = require('es-abstract/2024/IteratorStepValue'); var NormalCompletion = require('es-abstract/2024/NormalCompletion'); var ThrowCompletion = require('es-abstract/2024/ThrowCompletion'); var isAbstractClosure = require('es-abstract/helpers/isAbstractClosure'); var IsArray = require('es-abstract/helpers/IsArray'); var isIteratorRecord = require('es-abstract/helpers/records/iterator-record'); var some = require('es-abstract/helpers/some'); var callBound = require('call-bind/callBound'); var $indexOf = callBound('Array.prototype.indexOf'); var $slice = callBound('Array.prototype.slice'); var $splice = callBound('Array.prototype.splice'); var iterHelperProto = require('../IteratorHelperPrototype'); var SLOT = require('internal-slot'); // https://tc39.es/proposal-joint-iteration/#sec-IteratorZip module.exports = function IteratorZip(iters, mode, padding, finishResults) { if (!IsArray(iters) || !some(iters, isIteratorRecord)) { throw new $TypeError('`iters` must be a List of IteratorRecords'); } if (mode !== 'shortest' && mode !== 'longest' && mode !== 'strict') { throw new $TypeError('`mode` must be one of "shortest", "longest", or "strict"'); } if (!IsArray(padding)) { throw new $TypeError('`padding` must be a List'); } if (!isAbstractClosure(finishResults)) { throw new $TypeError('`finishResults` must be an Abstract Closure'); } var iterCount = iters.length; // step 1 var openIters = $slice(iters); // step 2 var sentinel = {}; var closure = function () { if (iterCount === 0) { // 1. If iterCount = 0, return ReturnCompletion(undefined). return sentinel; // step 1 } // while (true) { { // eslint-disable-line no-lone-blocks var results = []; // step 3.b.i if (openIters.length === 0) { throw new $TypeError('Assertion failed: `openIters` is empty'); // step 3.b.ii } for (var i = 0; i < iterCount; ++i) { // step 3.b.iii // for (var i = 0; i < iterCount; i += 1) { // step 3.b.iii var result; var iter = iters[i]; if (iter === null) { // step 3.b.iii.1 if (mode !== 'longest') { throw new $TypeError('Assertion failed: `mode` is not "longest"'); // step 3.b.iii.1.a } result = padding[i]; // step 3.b.iii.1.b } else { // step 2 try { result = IteratorStepValue(iter); // step 3.b.iii.2.a, 3.b.iii.2.c } catch (e) { // step 3.b.iii.2.b $splice(openIters, $indexOf(openIters, iter), 1); // step 3.b.iii.2.b.i return IteratorCloseAll(openIters, ThrowCompletion(e)); // step 3.b.iii.2.b.ii } if (iter['[[Done]]']) { // step 3.b.iii.2.d $splice(openIters, $indexOf(openIters, iter), 1); // step 3.b.iii.2.d.i if (mode === 'shortest') { // step 3.b.iii.2.d.ii IteratorCloseAll(openIters, NormalCompletion(undefined)); // step 3.b.iii.2.d.ii.i return sentinel; } else if (mode === 'strict') { // step 3.b.iii.2.d.iii if (i !== 0) { // step 3.b.iii.2.d.iii.i return IteratorCloseAll( openIters, ThrowCompletion(new $TypeError('Assertion failed: `i` is not 0')) ); // step 3.b.iii.2.d.iii.i.i } for (var k = 1; k < iterCount; k += 1) { // step 3.b.iii.2.d.iii.ii if (iters[k] === null) { throw new $TypeError('Assertion failed: `iters[k]` is `null`'); // step 3.b.iii.2.d.iii.ii.i } try { result = IteratorStep(iters[k]); // step 3.b.iii.2.d.iii.ii.ii, 3.b.iii.2.d.iii.ii.iii.ii.iv } catch (e) { // step 3.b.iii.2.d.iii.ii.iii return IteratorCloseAll(openIters, ThrowCompletion(e)); // step 3.b.iii.2.d.iii.ii.iii.ii } // if (open === false) { // step 3.b.iii.2.d.iii.ii.v if (iters[k]['[[Done]]']) { // step 3.b.iii.2.d.iii.ii.v $splice(openIters, $indexOf(openIters, iters[k]), 1); // step 3.b.iii.2.d.iii.ii.v.i } else { // step 3.b.iii.2.d.iii.ii.vi return IteratorCloseAll( openIters, ThrowCompletion(new $TypeError('Assertion failed: `open` is not `false`')) ); // step 3.b.iii.2.d.iii.ii.vi.i } } } else { // step 3.b.iii.2.d.iv if (mode !== 'longest') { throw new $TypeError('Assertion failed: `mode` is not "longest"'); // step 3.b.iii.2.d.iv.i } if (openIters.length === 0) { return sentinel; // ReturnCompletion(undefined); // step 3.b.iii.2.d.iv.ii } // eslint-disable-next-line no-param-reassign iters[i] = null; // step 3.b.iii.2.d.iv.iii // i += 1; result = padding[i]; // step 3.b.iii.2.d.iv.iv } } } results[results.length] = result; // step 3.b.iii.3 // 5. Let completion be Completion(Yield(results)). // 6. If completion is an abrupt completion, then // 1. Return ? IteratorCloseAll(openIters, completion). } } return finishResults(results); // step 3.b.iv }; SLOT.set(closure, '[[Sentinel]]', sentinel); // for the userland implementation SLOT.set(closure, '[[CloseIfAbrupt]]', finishResults); // for the userland implementation var gen = CreateIteratorFromClosure(closure, 'Iterator Helper', iterHelperProto, ['[[UnderlyingIterators]]']); // step 4 SLOT.set(gen, '[[UnderlyingIterators]]', openIters); // step 5 return gen; // step 6 };