proposal: Object Members

Ben Wiley therealbenwiley at
Mon Jul 23 22:43:40 UTC 2018

What exactly can be accomplished with super that can't be accomplished
otherwise? I know the transpiled code is very verbose and unintuitive to
read if you avoid explicitly naming the base class, but I wasn't aware of
new capabilities that were previously impossible.


Le lun. 23 juill. 2018 18 h 06, Ranando King <kingmph at> a écrit :

> Granted about `super()`. That's the one thing I can't easily reproduce.
> However, barring those internal slots, I can reproduce the functionality of
> `super` and the checks performed as a result of the internal slots, all in
> ES6. As for built-ins, I can easily and properly extend builtins without
> `class` since ES6 officially has `Object.setPrototypeOf()`. If you don't
> think it's possible, you should take a close look at what I'm doing in the
> link from my first post.
> As for whether or not the sugary nature of `class` is a good thing, it
> really is a matter of opinion. I just happen to be of the persuasion that
> since there's literally no construct that `class` can produce that I cannot
> reproduce by other means, then that means the `class` keyword (even in
> light of `super`) is little more than syntactic sugar. As such, we
> shouldn't be so hasty to turn an Object Oriented Prototype Based language
> into an Object Oriented Class Based language. The only way to do that
> reasonably is to ensure that whatever you can construct with `class` can
> always be equivalently constructed without it.
> Here's a more logical argument instead. Even if there are subtle
> differences between `class` constructors and object factory functions,
> providing an isolated path specific to `class` is likely to lead to
> situations very similar to what happens when an open source package gets
> forked. Eventually, the difference between the two paths may become so
> great that one is eventually abandoned (by developers) in favor of the
> other. This is only a valid argument because the power of ES is in it's
> simplicity. It's like building a house with wood, nails, sheetrock, etc...
> (JS) vs. building a house with pre-fabricated parts (class-based languages).
> Don't get me wrong. The `class` keyword is a great thing. It simplifies
> the production of creating object factories with prototypes. As I
> understand it, that was the purpose. Let's not make the mistake of allowing
> something to be done with `class` that cannot be reasonably reproduced
> without it. The moment we do that, we're diverging from the intended
> purpose of `class`.
> On Mon, Jul 23, 2018 at 4:17 PM Jordan Harband <ljharb at> wrote:
>> Extend builtins, in particular - ie, `super()` allows your subclass to
>> obtain internal slots it can't otherwise get.
>> Even if `class` were just sugar, I don't think I see the argument that
>> that's a *good* thing to preserve.
>> On Mon, Jul 23, 2018 at 2:05 PM, Ranando King <kingmph at> wrote:
>>> ---------- Forwarded message ---------
>>> From: Ranando King <kingmph at>
>>> Date: Mon, Jul 23, 2018 at 4:04 PM
>>> Subject: Re: proposal: Object Members
>>> To: <ljharb at>
>>> You've made that argument before. Exactly what is it in ES6 that you
>>> **can** do with `class` that you cannot do without class? I'd like some
>>> clarification on this.
>>> On Mon, Jul 23, 2018 at 3:30 PM Jordan Harband <ljharb at> wrote:
>>>> `class` is already not just syntactic sugar, so that notion isn't
>>>> correct, and shouldn't be maintained.
>>>> On Mon, Jul 23, 2018 at 12:38 PM, Ranando King <kingmph at>
>>>> wrote:
>>>>> I've written up a new draft proposal based on my own work with ES5 &
>>>>> ES6 compatible classes with fields. That can be found [here](
>>>>> I'm already aware
>>>>> of the class-members proposal, but I think it breaks far to many things and
>>>>> doesn't do anything to maintain the notion that "`class` is just syntactic
>>>>> sugar".
>>>>> This proposal is specifically based on the code [here](
>>>>> I've also got a
>>>>> []( that
>>>>> shows the same code running.
>>>>> The idea behind the proposal is that instead of injecting a lot of new
>>>>> logic into how `class` works, let's allow `class` to remain syntactic
>>>>> sugar, and put that extra ability into object declarations instead. Then
>>>>> simply allow `class` to do the same with it's own prototypes.
>>>>> _______________________________________________
>>>>> es-discuss mailing list
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