[news.eclipse.tools.uml2] Re: Is Feature Refinement supported ?

["Antonio Carrasco \(MDDltd\)" <acv@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Great !


"Kenn Hussey" <khussey@xxxxxxxxxx> wrote in message 
news:ehljli$m3u$1@xxxxxxxxxxxxxxxxxxxx
> Antonio,
>
> Feature refinement (redefinition and subsetting) is supported by the UML2 
> code generator extension...
>
> Kenn
>
> "Antonio Carrasco Valero" <acv@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in 
> message news:ehlcbp$kmk$1@xxxxxxxxxxxxxxxxxxxx
>> Hi Ed!
>>
>> Should we consider thes limitation,
>> of eCore not allowing redefinition of features in subclasses,
>> as something to resolve in the future ?
>>
>> This seriously impairs the ability to reuse Eclipse UML implementation in 
>> DSLs.
>>
>> I believe that that, in the very honest goal
>> of keeping EMF codegen straightforward,
>> those honestly interested in the reuse of Eclipse UML in their DSLs,
>> will be seriously discouraged to do so.
>>
>> This limitation forces to do all kinds of nasty hacks in the metamodels,
>> that´s why it is used all over the UML2 specification
>> (and why package merge and UML flattening is possible).
>>
>> Other ways of constraining, apart from subclassing UML,
>> still leave a metamodel that is exactly like the original, unrefined one,
>> when inspected reflectively.
>> This amounts the same as creating Profiles of UML
>> - as many are so intelligently doint, given the obstacles to derive  DSLs 
>> from UML.
>>
>> Cheers,
>> Antonio Carrasco Valero
>> Model Driven Development ltd.
>>
>>
>>
>>
>> "Ed Merks" <merks@xxxxxxxxxx> wrote in message 
>> news:ehkt0k$ehc$1@xxxxxxxxxxxxxxxxxxxx
>>> Antonio,
>>>
>>> This is possible in UML2 but not in Ecore.  The UML2 Ecore  importer 
>>> will create new features (with a different name)s for such a cases. 
>>> Narrowing the multiplicity isn't even possible with Java , i.e., 
>>> List<X> getX can't be overridden with X getX(), and narrowing the type 
>>> would only be possible for single valued features in Java 5.0, i.e., X 
>>> getX() can be overridden by Y getX() if Y inherits from X, and isn't 
>>> possible for multi-valued features in Java 5.0 because there is no 
>>> inheritance relation between List<X> and List<Y> regardless of the 
>>> inheritance relation between X and Y, i.e., List getX can be overridden 
>>> by List getX but List<X> getX cannot be overridden by List<Y> getX. 
>>> It's usually best to consider such refinements to be constraints rather 
>>> than to expect the API itself to morph since Java is not completely 
>>> capable of expressing this.
>>>
>>>
>>> Antonio Carrasco Valero wrote:
>>>> Hi !
>>>> Is it possible to refine features in subclasses ?
>>>> i.e, define in a sub-EClass,
>>>> an EReference feature that re-defines the referenced type
>>>> to an specialization of the type referenced by the supertype,
>>>> or that narrows multiplicity from 1..n to 1..1, ...
>>>>
>>>>
>>>>
>>>>
>>>>
>>
>>
>
>