diff options
Diffstat (limited to 'src/node_modules/es-abstract/2019/IteratorClose.js')
-rw-r--r-- | src/node_modules/es-abstract/2019/IteratorClose.js | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/node_modules/es-abstract/2019/IteratorClose.js b/src/node_modules/es-abstract/2019/IteratorClose.js new file mode 100644 index 0000000..35c8c2b --- /dev/null +++ b/src/node_modules/es-abstract/2019/IteratorClose.js @@ -0,0 +1,50 @@ +'use strict'; + +var GetIntrinsic = require('../GetIntrinsic'); + +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; +}; |