[Laszlo-dev] how to handle user-defined classes in the swf9 runtime

Mon Jan 7 14:34:52 PST 2008

No, I think devildog is the right target for this.  We have a working  
solution for JS1 already, so we just need to add this to the js2 back  
end.  As we do, we may decide to restrict what you can do with a mixin  
to what is easy to implement, which would mean tightening up the js1  
implementation.

On 2008-01-07, at 17:30 EST, Donald Anderson wrote:

> It was already filed in JIRA as:
>  http://www.openlaszlo.org/jira/browse/LPP-5266
>
> It's marked for Devildog, possibly it needs to be more encompassing  
> than that.
>
> I just added the recent emails as comments to the JIRA.
>
>
> On Jan 7, 2008, at 4:31 PM, P T Withington wrote:
>
>> We have a plan!
>>
>> A _mixin_ (we need to update our terminology) is really just an  
>> _interface_ with implementation.  The JS2 back end, when it sees a  
>> mixin has to remember the implementation, and has to emit an  
>> interface declaration (i.e., copy the declaration through,  
>> stripping out any implementation -- actually, initially, it could  
>> leave out the body altogether I think).  Then, for each class that  
>> uses that mixin:
>>
>> mixin amixin { <body of amixin> };
>>
>> mixin bmixin { <body of bmixin> };
>>
>> class aclass extends anotherclass with amixin, bmixin { <body of  
>> aclass> };
>>
>> the compiler has to emit 'interstitial' classes:
>>
>> interface bmixin {};
>>
>> class lzsc::bmixin$anotherclass extends anotherclass implements  
>> bmixin {
>>   <body of bmixin>
>> };
>>
>> interface amixin {};
>>
>> class lzsc::amixin$bmixin$anotherclass extends lzsc::bmixin 
>> $anotherclass implements amixin {
>>   <body of amixin>
>> }
>>
>> class aclass extends lzsc::amixin$bmixin$anotherclass implements  
>> amixin, bmixin { <body of aclass> }
>>
>> Don, if we don't have a task filed for this, please file one.
>>
>> On 2008-01-07, at 16:08 EST, Henry Minsky wrote:
>>
>>> So what should we do with traits, I wonder.
>>>
>>>
>>> On Jan 7, 2008 3:36 PM, P T Withington <ptw at pobox.com> wrote:
>>>> Remember Class.lzs is really just the runtime support for JS2 class
>>>> semantics in a JS1 runtime.  So the goal is to have that be  
>>>> unused in
>>>> a JS2 runtime (like swf9).
>>>>
>>>>
>>>> On 2008-01-07, at 15:34 EST, P T Withington wrote:
>>>>
>>>>> I agree.
>>>>>
>>>>> I'm just not sure if we need a UserClass (that is a subclass of
>>>>> view) that these classes inherit from, or if they can just  
>>>>> directly
>>>>> inherit from view (or some other lfc class).  There is some stuff
>>>>> that happens in UserClass that is different from node.
>>>>>
>>>>> On 2008-01-07, at 15:30 EST, Henry Minsky wrote:
>>>>>
>>>>>> I think the most pragmatic thing to do is to bite the bullet,  
>>>>>> so to
>>>>>> speak, and make
>>>>>> the tag compiler emit class { .... } declarations for user- 
>>>>>> defined
>>>>>> classes. It seems like
>>>>>> the alternative would be to use our Class.lzs in swf9 for user-
>>>>>> defined classes
>>>>>> at runtime, which seems like it would cause all sorts of  
>>>>>> confusion.
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Henry Minsky
>>>>>> Software Architect
>>>>>> hminsky at laszlosystems.com
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> -- 
>>> Henry Minsky
>>> Software Architect
>>> hminsky at laszlosystems.com
>>
>
>
> --
>
> Don Anderson
> Java/C/C++, Berkeley DB, systems consultant
>
> voice: 617-547-7881
> email: dda at ddanderson.com
> www: http://www.ddanderson.com
>
>
>
>