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

Tue Jan 8 05:26:15 PST 2008

Thanks André.  So Henry, we need to know if an as3 interface can have  
static properties.  Or, we need an idea of how to emulate that.  Maybe  
these just become static properties of the class that uses the mixin?   
That's slightly more work for the js2 back-end than my previous  
scheme, though.

On 2008-01-08, at 03:54 EST, André Bargull wrote:

> These two traits/mixins have got static vars resp. functions:  
> "LzDataNode" and "LzDataElementTrait"
>
> - "LzDataElementTrait.valueToElement(..)"
> - "LzDataElementTrait.__LZv2E(..)"
> - "LzDataNode.ELEMENT_NODE, TEXT_NODE, DOCUMENT_NODE"
> - "LzDataNode.__LZescapechars"
> - "LzDataNode.stringToLzData(..)"
> - "LzDataNode.whitespaceChars"
> - "LzDataNode.trim(..)"
>
>> I haven't come across it used yet in any of our LFC code, just wanted
>> to watch out in case it showed up.
>>
>>
>>
>> On Jan 7, 2008 4:54 PM, P T Withington <ptw at pobox.com wrote:
>>
>>> In our (ill-defined) mixin's, we allow both static vars and
>>> functions.  Not sure how we would implement that in JS2 though,
>>> because I don't think and interface allows either.  If an interface
>>> does, we are all set.  Perhaps you should try it?
>>>
>>> Do we use this feature?  If we do, we'll have to figure out a way to
>>> support it, I guess.
>>>
>>>
>>> On 2008-01-07, at 16:40 EST, Henry Minsky wrote:
>>>
>>>
>>>
>>>>  Can you have static "class variables" declared on a mixin?
>>>>     On Jan 7, 2008 4:31 PM, P T Withington <ptw at pobox.com 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
>>>>>>
>>>>>
>>>>     --
>>>>  Henry Minsky
>>>>  Software Architect
>>>>  hminsky at laszlosystems.com
>>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>> -- Henry Minsky Software Architect hminsky at laszlosystems.com
>