50 lines
1.4 KiB
JavaScript
50 lines
1.4 KiB
JavaScript
'use strict';
|
|
|
|
var GetIntrinsic = require('get-intrinsic');
|
|
|
|
var $TypeError = GetIntrinsic('%TypeError%');
|
|
|
|
var Call = require('./Call');
|
|
var GetMethod = require('./GetMethod');
|
|
var IsCallable = require('./IsCallable');
|
|
var Type = require('./Type');
|
|
|
|
// https://ecma-international.org/ecma-262/6.0/#sec-iteratorclose
|
|
|
|
module.exports = function IteratorClose(iterator, completion) {
|
|
if (Type(iterator) !== 'Object') {
|
|
throw new $TypeError('Assertion failed: Type(iterator) is not Object');
|
|
}
|
|
if (!IsCallable(completion)) {
|
|
throw new $TypeError('Assertion failed: completion is not a thunk for a Completion Record');
|
|
}
|
|
var completionThunk = completion;
|
|
|
|
var iteratorReturn = GetMethod(iterator, 'return');
|
|
|
|
if (typeof iteratorReturn === 'undefined') {
|
|
return completionThunk();
|
|
}
|
|
|
|
var completionRecord;
|
|
try {
|
|
var innerResult = Call(iteratorReturn, iterator, []);
|
|
} catch (e) {
|
|
// if we hit here, then "e" is the innerResult completion that needs re-throwing
|
|
|
|
// if the completion is of type "throw", this will throw.
|
|
completionThunk();
|
|
completionThunk = null; // ensure it's not called twice.
|
|
|
|
// if not, then return the innerResult completion
|
|
throw e;
|
|
}
|
|
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;
|
|
};
|