Enumerability

Rick Waldron waldron.rick at gmail.com
Sun Jan 12 20:20:18 PST 2014


On Sat, Jan 11, 2014 at 12:24 PM, Andrea Giammarchi <
andrea.giammarchi at gmail.com> wrote:

> I would like to see some Rick or David example about the "expected to be
> enumerable".
>
> If that's about knowing if a class is native or not, looping with a for/in
> its prototype or any instance does not seem to mean anything reliable since
> even native methods can be redefined and made enumerable.
>

Making concise method definitions default to enumerable: true had _nothing_
to do with classes and everything to do with code that *consumes* objects
with concise method definitions. Refactoring this:

  var o = {
    method: function() {
    }
  };

To this:

  var o = {
    method() {
    }
  };


Should absolutely not change the resulting behaviour of a for-in loop over
o's properties. I don't know why Allen said that for-in has been deprecated
in favor of for-of, since the latter doesn't imply iteration over the
properties of a plain object. That's not going away.

Rick
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20140112/714c2058/attachment.html>


More information about the es-discuss mailing list