Code smell? Iterator prototype has iterator method that returns "this"
Michael Theriot
michael.lee.theriot at gmail.com
Wed Jul 27 23:02:28 UTC 2016
At least in Chrome, new weirdFunction() !== iter nor does it throw a
TypeError... but maybe that's a bug...
On Wed, Jul 27, 2016 at 10:12 AM, Allen Wirfs-Brock <allen at wirfs-brock.com>
wrote:
>
> 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 which
> is a built-in function that is not identified as a constructor.
>
> 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 says:
> If IsConstructor(*constructor*) is *false*, throw a TypeError exception.
>
>
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