33 lines
1.0 KiB
Plaintext
33 lines
1.0 KiB
Plaintext
'use strict';
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var $TypeError = require('es-errors/type');
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var GetIteratorFlattenable = require('../aos/GetIteratorFlattenable');
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var OrdinaryHasInstance = require('es-abstract/2023/OrdinaryHasInstance');
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var OrdinaryObjectCreate = require('es-abstract/2023/OrdinaryObjectCreate');
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var $Iterator = require('../Iterator/polyfill')();
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var $WrapForValidIteratorPrototype = require('../WrapForValidIteratorPrototype');
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var SLOT = require('internal-slot');
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module.exports = function from(O) {
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if (this instanceof from) {
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throw new $TypeError('`Iterator.from` is not a constructor');
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}
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var iteratorRecord = GetIteratorFlattenable(O, 'iterate-strings'); // step 1
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var hasInstance = OrdinaryHasInstance($Iterator, iteratorRecord['[[Iterator]]']); // step 2
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if (hasInstance) { // step 3
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return iteratorRecord['[[Iterator]]']; // step 3.a
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}
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var wrapper = OrdinaryObjectCreate($WrapForValidIteratorPrototype); // , ['[[Iterated]]']); // step 4
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SLOT.set(wrapper, '[[Iterated]]', iteratorRecord); // step 5
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return wrapper; // step 6
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};
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