94 lines
2.8 KiB
Plaintext
94 lines
2.8 KiB
Plaintext
'use strict';
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var $RangeError = require('es-errors/range');
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var $TypeError = require('es-errors/type');
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var CompletionRecord = require('es-abstract/2023/CompletionRecord');
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var CreateIteratorFromClosure = require('../aos/CreateIteratorFromClosure');
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var GetIteratorDirect = require('../aos/GetIteratorDirect');
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var IteratorClose = require('../aos/IteratorClose');
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var IteratorStep = require('es-abstract/2023/IteratorStep');
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var IteratorStepValue = require('../aos/IteratorStepValue');
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var ThrowCompletion = require('es-abstract/2023/ThrowCompletion');
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var ToIntegerOrInfinity = require('es-abstract/2023/ToIntegerOrInfinity');
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var ToNumber = require('es-abstract/2023/ToNumber');
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var Type = require('es-abstract/2023/Type');
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var iterHelperProto = require('../IteratorHelperPrototype');
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var isNaN = require('es-abstract/helpers/isNaN');
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var SLOT = require('internal-slot');
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module.exports = function drop(limit) {
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if (this instanceof drop) {
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throw new $TypeError('`drop` is not a constructor');
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}
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var O = this; // step 1
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if (Type(O) !== 'Object') {
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throw new $TypeError('`this` value must be an Object'); // step 2
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}
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var numLimit = ToNumber(limit); // step 2
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if (isNaN(numLimit)) {
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throw new $RangeError('`limit` must be a non-NaN number'); // step 3
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}
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var iterated = GetIteratorDirect(O); // step 4
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var integerLimit = ToIntegerOrInfinity(numLimit); // step 4
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if (integerLimit < 0) {
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throw new $RangeError('`limit` must be a >= 0'); // step 5
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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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IteratorClose(
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iterated,
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abruptCompletion
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);
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};
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var sentinel = {};
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var remaining = integerLimit; // step 6.a
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var closure = function () { // step 6
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var next;
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while (remaining > 0) { // step 6.b
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if (remaining !== Infinity) { // step 6.b.i
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remaining -= 1; // step 6.b.i.1
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}
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next = IteratorStep(iterated); // step 6.b.ii
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if (!next) {
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// return void undefined; // step 6.b.iii
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return sentinel;
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}
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}
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// while (true) { // step 6.c
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try {
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var value = IteratorStepValue(iterated); // step 6.b.i
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if (iterated['[[Done]]']) {
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return sentinel; // step 6.b.ii
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}
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return value;
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} catch (e) {
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// close iterator // step 6.c.icv
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closeIfAbrupt(ThrowCompletion(e));
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throw e;
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}
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// }
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// return void undefined;
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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 result = CreateIteratorFromClosure(closure, 'Iterator Helper', iterHelperProto, ['[[UnderlyingIterator]]']); // step 4
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SLOT.set(result, '[[UnderlyingIterator]]', iterated); // step 5
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return result; // step 6
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};
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