[news.eclipse.tools.emf] Re: The definitive truth about multiple inherit

[Ed Merks <Ed.Merks@xxxxxxxxx>]

Guillaume,

Comments below...

Guillaume Vauvert wrote:
> Ed,
>
> I will try to decrease your headache ...
> > I keep reading this and it's making my brain hurt.  Maybe you could 
> > draw a picture or make explicit what methods you're talking about.  
> > Is D inheriting from C or is it A that's doing that, or is the comma 
> > implying that C inherits from Class but is otherwise unrelated?
> You are right : my explanation is more complex than what I want to 
> describe.
> So :
> - A inherits from Action
> - C inherits from Class
Class is a bit of a confusing name.
> - D inherits from both A and C
> So simple when it is clear !
>
> The generated code :
> - the class DImpl extends the class AImpl : it is OK.
> - the class DImpl implements the interface D ; the interface D extends 
> the interface A and the interface C.
>     - the class DImpl inherits methods from AImpl : so it implements 
> the interface A;
>     - the class DImpl contains methods that are declared in the 
> interface C ;
>     - BUT DImpl does not contain methods that are inherited by the 
> interface C from the interface Class.
Did you declare all these methods in Ecore's version of Class?  I'm 
suspicious about that name...
> So, the class DImpl should be declared abstract, because it does not 
> implements the methods inherited by the interface C that it should 
> implement.
I have this suspicion that perhaps Class has methods in Java, that you 
didn't actually declare as EOperation in the Ecore wrapper...
> > The point that is that if you consider the super types Y and Z of an 
> > EClass X, XImpl will extend YImpl and will generate a clone of what's 
> > in ZImpl.  So it should indeed be possible to generate a complete 
> > implementation.
> It is exactly what I expect. Instead, I get a partial implementation.
You've not been entirely clear if you're talking about EOperations or 
EStructuralFeatures, which leads to my suspicion about what you declared 
in Ecore verses what's there in Java....
> > > What can I do to solve my problem ?
> > Are you saying that's generated doesn't compile?
> Yes, it does not compile, because the class lacks some methods, those 
> from the class Class inherited by the interface C.
>
> Do you see what is my problem now ?
Yes, but I'm more suspicious that there's something you've not stated 
explicitly.  EMF won't know to implement a method if there's no 
EOperation declared for it in Class.  I'm pretty sure if you specify the 
right EOperations, there's at least be stub methods generated.
> And do you see a solution ... ?
I'd suggest you provide an example model that I can use to reproduce the 
problem.  Then I can tell you if the problem is your model or in the 
framework.
> Guillaume Vauvert
> http://www.ixmas.org