What can classes do that ES6 can't? On Tuesday, July 24, 2018, Andrea Giammarchi <[email protected]> wrote:
> > Proxy was used to create a membrane between the public and private > storage, and I can't prevent that proxy from being passed to external > functions > > this already underlines what I mean: classes are not just syntactic sugar > because you cannot replicate what they do, not even using ES6. > > having privates / proxies maybe exposed is not how I'd personally code. > > > > On Tue, Jul 24, 2018 at 5:15 PM Ranando King <[email protected]> wrote: > >> > Private fields also won't work as expected... >> >> Can you clarify what you're referring to? I've created a library that >> essentially implements the functional parts of what I intend with this >> proposal. Of course the syntax isn't the same, and Proxy was used to create >> a membrane between the public and private storage, and I can't prevent that >> proxy from being passed to external functions, but those are ES-specific >> implementation details and not how it would be implemented in the engine. >> >> > ... the mandatory super call in constructor is also different from >> ES5. >> >> You shouldn't really try to compare ES5 and ES6. My statement that >> "`class` is syntactic sugar" refers to the fact that anything you can do >> with `class` in ES6 can also be done without `class` in ES6. >> >> > P.S. Babel mistakenly sold classes as "just sugar" and never worked >> properly with Custom Elements and builtins extend until version 7 which is >> still not perfect but at least it doesn't throw errors for no reason. >> >> Just because `class` is essentially syntactic sugar doesn't mean that the >> desugaring is backwards compatible with older versions of the language. I >> do not wish to imply that. Nor do I see the need to make such a statement >> true. Such an attempt to enforce backwards compatibility to that degree >> would prove excessively burdensome on the process of improving and adding >> features to the language. >> >> On Tue, Jul 24, 2018 at 9:41 AM Andrea Giammarchi < >> [email protected]> wrote: >> >>> Private fields also won't work as expected and the mandatory super call >>> in constructor is also different from ES5. Let's add species and special >>> class related Symbol so that it makes no sense to define classes "just >>> sugar" + there's no point in avoiding classes at all costs when any of >>> these features is needed. >>> >>> Regards >>> >>> P.S. Babel mistakenly sold classes as "just sugar" and never worked >>> properly with Custom Elements and builtins extend until version 7 which is >>> still not perfect but at least it doesn't throw errors for no reason >>> >>> >>> On Tue, Jul 24, 2018 at 4:15 PM Ranando King <[email protected]> wrote: >>> >>>> @ljharb: It seems you now understand what I was trying to say. Sadly, >>>> I'm not always the most eloquent. >>>> >>>> > As you've all pointed out, it's not "just sugar" in the sense that >>>> you couldn't do it in ES5; it's more that parallel syntax and API were >>>> created for the new functionality in ES6. >>>> >>>> The intent of my proposal is to provide both member fields and >>>> privilege levels to the `class` keyword, and the equivalent for object >>>> literals in a way that meets with both an intuitive declaration style, and >>>> a reasonable access notation that breaks as little as few as possible of >>>> the developers expectations of what can and can't be done. >>>> >>>> On Tue, Jul 24, 2018 at 3:18 AM Jordan Harband <[email protected]> >>>> wrote: >>>> >>>>> As you've all pointed out, it's not "just sugar" in the sense that you >>>>> couldn't do it in ES5; it's more that parallel syntax and API were created >>>>> for the new functionality in ES6. Thanks for providing clear code examples >>>>> of how one might extend builtins without `class`. >>>>> >>>>> @kai: yes, extending builtins makes sense, in that it's an important >>>>> part of ES6. Invoking "the web" doesn't negate *any* of the features of >>>>> the >>>>> language, new or old. Separately, not every web use involves any JSON >>>>> serialization in either direction. >>>>> >>>>> On Tue, Jul 24, 2018 at 12:15 AM, T.J. Crowder < >>>>> [email protected]> wrote: >>>>> >>>>>> On Tue, Jul 24, 2018 at 8:00 AM, Michael Theriot >>>>>> <[email protected]> wrote: >>>>>> > `Reflect.construct` allows subclasses to obtain internal slots >>>>>> without >>>>>> > `super()` / class syntax. >>>>>> >>>>>> Indeed, Darien pointed that out as well (and if you two hadn't, I >>>>>> would have. :-) >>>>>> >>>>>> > This is the first I have heard `class` is anything but sugar. >>>>>> >>>>>> The accurate statement would be that `class` lets you do things you >>>>>> couldn't do in ES5. But so does `Reflect.construct`. I believe it was >>>>>> important to the "no `new`" crowd that a non-`class` mechanism existed >>>>>> for >>>>>> creating objects using Error and Array as prototypes. >>>>>> >>>>>> -- T.J. Crowder >>>>>> >>>>> >>>>> _______________________________________________ >>>>> es-discuss mailing list >>>>> [email protected] >>>>> https://mail.mozilla.org/listinfo/es-discuss >>>>> >>>> _______________________________________________ >>>> es-discuss mailing list >>>> [email protected] >>>> https://mail.mozilla.org/listinfo/es-discuss >>>> >>>
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
