Convergence options for Ecmascript/Actionscript?

Claus Reinke claus.reinke at talk21.com
Wed Aug 29 02:05:57 PDT 2012


Since this seems to be open to misinterpretation:

I'm looking at this from a JS developer perspective, and since ES4
failed, I was *not* asking to make ES6 any more like AS3.

What I thought would be interesting can be reduced to two points:

1. promoting ES6 to AS3 developers, so that they do not get hung
    up about "downgrading" from AS3 to ES5, when support for ES6
    features like minimal classes and proper modules are just around
    the corner

2. getting feedback from AS3 developers: did they really need the
    extra features that ES.nexts are not going to have, what was their
    experience with the features that AS3 has in some form and ES6
    is going to have in some other form. And do those who went
    through the AS3 to ES5 transition have useful observations?

So the changes would be for AS3 and its developers to make
(and it is my impression that Adobe is already working on cross
exports from their tools to HTML/Javascript), but the changes
from ES5 to ES6 could help them, and there might be something
to learn from AS3 developer experience.

Hope this avoids misunderstandings,
Claus

> What Brendan said.
>
> Let me just add this:
>
> Flash isn't about AS3 (particularly). It's an entire environment, event
> model, rich library of APIs, and a deep toolchain that allows developers to
> be productive. Even if we were to adopt the (foolish) goal of adding
> missing AS3 features to ES, that wouldn't allow Flash developers (as a
> group) to move seamlessly to a JS world.
>
> Flash always has been a compiler-mediated format. Their bytecode is
> testament to that. To the extent that there's going to be a transition
> strategy, I expect it to be a feature of the system that already has the
> user-exposed compile step (Flash), not the one that doesn't (JS).
>
> Regards
>
>
> On Wed, Aug 29, 2012 at 1:30 AM, Brendan Eich <brendan at mozilla.org> wrote:
>
>> Claus Reinke wrote:
>>
>>> Hope this isn't politically inappropriate here;-)
>>>
>>> 1. Flash is dying as a browser plugin, but otherwise still alive,
>>>    especially with compilation of Actionscript to native code [2,3].
>>>
>>> 2. Adobe has been growing support for HTML/Javascript options.
>>>
>>> 3. Actionscript is based on an old ES draft standard that failed to
>>>    reach consensus, partly because its changes were considered
>>>    too much at once. [my impression - I don't have a reference]
>>>
>>
>> You really should read back in es-discuss if you have time (understand if
>> you don't!). We covered what made ES4 fail. The main problem was
>> namespaces, upon which packages were built.
>>
>> Unfortunately, AS3 uses namespaces and packages heavily. Mozilla's Shumway
>> project includes an AS3 bytecode recompiler that generates JS, and we
>> cannot lower namespaces to anything native and JIT-optimized in JS itself.
>> Cc'ing Tobias in case he can comment.
>>
>>
>>  4. Lots of Actionscript developers find themselves having to
>>>    grow accustomed to the world of HTML/Javascript
>>>
>>
>> Developers do adapt, of course.
>>
>>
>>  One consequence of 4 are blog posts about "Javascript technology
>>> X, for Flash developers". When I read such blog posts (eg, [1], with
>>> side-by-side comparisons of AS and JS code), I get the feeling that
>>> the transition would be much easier from AS3 to ES6, where things
>>> like modules and minimal classes exist. There is an opportunity here,
>>> if those parts of the standard are sufficiently stable to recommend
>>> transpiling (until real ES6 implementations come along).
>>>
>>
>> Namespaces and packages are the problems (really one problem, namespaces
>> making lookup three dimensional rather than two dimensions (proto and scope
>> chain).
>>
>>
>>  One consequence of 3 is that there should be a vibrant community
>>> of AS developers who have practical experience with features similar
>>> to those considered for ES6, in a Javascript-like language.
>>>
>>
>> Not similar enough, in my view. Not only does AS3 have namespaces, it uses
>> them for class-private and IIRC protected visibility. IIRC AS3 classes do
>> not have class-side inheritance (just like Java), another difference.
>>
>> Finally, AS3 was really intended, along with an implicitly early-bound
>> namespace, to statically judge the meaning of names and even types. Its
>> code loading and global object model is entirely unlike the Web's.
>>
>>
>>  Yet I
>>> do not see any experience reports or spec feedback based on that
>>> here on this list. Wouldn't it be very helpful to invite such input?
>>>
>>
>> I think not. Some of us were involved intimately in ES4. We have the scars
>> and remember the differences. ES6 does not need more constraints or feature
>> demands from newcomers. That is a sure way to kill it.
>>
>>
>>  I don't expect Actionscript developers want to lose any of their
>>> language features, but there might be profit (for both AS and ES
>>> developers) if Adobe could try to align AS4 to ES6 so that the
>>> common language subsets have common syntax and semantics.
>>>
>>
>> That's up to Adobe, but I recall that they are talking about going more
>> their own way:
>>
>> http://www.kirupa.com/forum/**showthread.php?371078-**
>> ActionScript-quot-Next-quot-**Flash-Roadmap<http://www.kirupa.com/forum/showthread.php?371078-ActionScript-quot-Next-quot-Flash-Roadmap>
>>
>>
>>  Such a hypothetical AS4 would be a typed version of ES6, making
>>> it easier for Adobe's tools to support both, and making it easier
>>> for developers to use or maintain either.
>>>
>>
>> No typed (static) version can work interoperably and soundly with the
>> dynamic language. This was one of the conclusions of the ES4 work. How to
>> interface typed and untyped (dynamically typed) code is still research. Sam
>> Tobin-Hochstadt's Typed Racket work is one example of research along the
>> lines of interconnecting dynamic and static code without losing soundness.
>>
>> Even throwing out soundness may break interop. We'll see how this works
>> for Dart, but right now Dart is a dynamic language with an early warning
>> system.
>>
>>
>>  Are there any Adobe folks listening here? Does anyone have the
>>> contacts to raise the question with them? Do you agree that there
>>> is potential for useful exchange of information and joining of
>>> efforts if the wall between AS and ES could be lowered?
>>>
>>
>> Adobe folks departed the Ecma TC39 field, although IIRC Adobe remainds a
>> member of www.ecma-international.org.
>>
>> Again I must comment that ES6 wants no new constraints and pressures.
>> Scope creep is the enemy.
>>
>> Also, you should not ignore the ES4 lessons learned or assume the problems
>> were not material and inherent to the divergence between AS3 and ES3.
>>
>> /be
>>
>>
>> ______________________________**_________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/**listinfo/es-discuss<https://mail.mozilla.org/listinfo/es-discuss>
>>
>

 



More information about the es-discuss mailing list