Code smell? Iterator prototype has iterator method that returns "this"
allen at wirfs-brock.com
Wed Jul 27 15:12:46 UTC 2016
> On Jul 26, 2016, at 11:52 PM, Claude Pache <claude.pache at gmail.com> wrote:
>> var weirdInstance = new weirdFunction(); // what is this??
> My intuition says: "TypeError: weirdFunction is not a constructor”.
exactly, because weirdFunction is actually https://tc39.github.io/ecma262/#sec-%iteratorprototype%-@@iterator <https://tc39.github.io/ecma262/#sec-%25iteratorprototype%25-@@iterator> which is a built-in function that is not identified as a constructor.
https://tc39.github.io/ecma262/#sec-ecmascript-standard-built-in-objects <https://tc39.github.io/ecma262/#sec-ecmascript-standard-built-in-objects> says:
"Built-in function objects that are not identified [in this specification] as constructors do not implement the [[Construct]] internal method unless otherwise specified in the description of a particular function.”
Step 7 of https://tc39.github.io/ecma262/#sec-evaluatenew <https://tc39.github.io/ecma262/#sec-evaluatenew> says: If IsConstructor(constructor) is false, throw a TypeError exception.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the es-discuss