1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162 |
- 'use strict';
- var GetIntrinsic = require('get-intrinsic');
- var $TypeError = GetIntrinsic('%TypeError%');
- var Call = require('./Call');
- var CompletionRecord = require('./CompletionRecord');
- var GetMethod = require('./GetMethod');
- var IsCallable = require('./IsCallable');
- var Type = require('./Type');
- var assertRecord = require('../helpers/assertRecord');
- // https://262.ecma-international.org/14.0/#sec-iteratorclose
- module.exports = function IteratorClose(iteratorRecord, completion) {
- assertRecord(Type, 'Iterator Record', 'iteratorRecord', iteratorRecord);
- if (Type(iteratorRecord['[[Iterator]]']) !== 'Object') {
- throw new $TypeError('Assertion failed: iteratorRecord.[[Iterator]] must be an Object'); // step 1
- }
- if (!IsCallable(completion) && !(completion instanceof CompletionRecord)) { // step 2
- throw new $TypeError('Assertion failed: completion is not a thunk representing a Completion Record, nor a Completion Record instance');
- }
- var completionThunk = completion instanceof CompletionRecord ? function () { return completion['?'](); } : completion;
- var iterator = iteratorRecord['[[Iterator]]']; // step 3
- var iteratorReturn;
- try {
- iteratorReturn = GetMethod(iterator, 'return'); // step 4
- } catch (e) {
- completionThunk(); // throws if `completion` is a throw completion // step 6
- completionThunk = null; // ensure it's not called twice.
- throw e; // step 7
- }
- if (typeof iteratorReturn === 'undefined') {
- return completionThunk(); // step 5.a - 5.b
- }
- var innerResult;
- try {
- innerResult = Call(iteratorReturn, iterator, []);
- } catch (e) {
- // if we hit here, then "e" is the innerResult completion that needs re-throwing
- completionThunk(); // throws if `completion` is a throw completion // step 6
- completionThunk = null; // ensure it's not called twice.
- // if not, then return the innerResult completion
- throw e; // step 7
- }
- var completionRecord = completionThunk(); // if innerResult worked, then throw if the completion does
- completionThunk = null; // ensure it's not called twice.
- if (Type(innerResult) !== 'Object') {
- throw new $TypeError('iterator .return must return an object');
- }
- return completionRecord;
- };
|