[news.eclipse.epsilon] Re: Help on the steps to follow for a model compo

[Juan Pedro Silva <jpsilvagallino@xxxxxxxxx>]

Thank you very much Dimitris for you quick reply.
Is a little more complicated: MMA and MMB elements have no notion of 
each other whatsoever.
Is a little more like this:

-- A.emf --                                                           

class A {                                                               
 attr String name;
 attr AComplexType propertyA;
}

-- B.emf --

class B {
 attr String name; 
 attr BComplexType propertyB;
}

-- C.emf --

class C {
 attr String name;
 attr AComplexType propertyA;
 attr BComplexType propertyB;
}

And the only merging would be the one that is stated in the modelink 
(particular elements, not all elements from two metaclasses with each 
other).
I mean, not all "class A" elements are merged with all "class B" 
elements, only the particular merging that was specified.
In the ecl I matched the root elements (which are supposed to be 
merged), but the rest of the elements (all from model A, only some from 
model B) must be copied into model C.
(I've used ATL/AMW for some time, so I may have biased ideas, please 
apologize me if such ideas are wrong!!)

From your answer I get that (not completely sure I'm right) I should 
not use the model generated in the modelink for anything, but state the 
same in the ecl, right?
(I get this because when you say "transform", I believe there is no 
actual means of generating the ecl from the other model, and I should do 
it by hand).
If so, should I check for the different ids (names) of the elements and 
if thats the correct combination, return true in the compare clause?. I 
believe there might be other way to do this.

Thanks for your help.


Dimitris Kolovos escribiÃ:
> Hi Juan-Pedro,
>
> ECL is used in order to establish a match trace (i.e. the 
> correspondences on which EML can then merge the models). Since you 
> already have an intermediate model, you can use ECL to "transform" it 
> to a match trace.
>
> So if your metamodels are:
>
> -- A.emf --
>
> class A {
>   attr String name;
> }
>
> -- B.emf --
>
> class B {
>   ref A a;
>   attr String annotation;
> }
>
> -- C.emf --
>
> class C {
>   attr String name;
> }
>
> your ECL comparison will look something like this:
>
> rule AB
>   match a : AModel!A
>   with b : BModel!B {
>
>   compare {
>     return b.a = a;
>   }
> }
>
> and your EML merging will look like this:
>
> rule AB2C
>   merge a : AModel!A
>   with b : BModel!B
>   into c : CModel!C {
>
>   c.name = a.name + '_' b.annotation;
> }
>
> Hope this helps. If not, please let me know.
>
> Cheers,
> Dimitris
>
> Juan Pedro Silva wrote:
> > Hi everybody.
> > I'm taking my first steps with Epsilon (EML mostly), and I'm trying 
> > to compose Model A (from Metamodel A) and Model B (from Metamodel B) 
> > into Model C (from Metamodel C). Two inputs, one output, three 
> > different metamodels.
> > I have already defined the metamodels, the emfatic file with the 
> > relationships between the input metamodels, and generated the 
> > correspondent ecore model. I also created a ".modelink" indicating 
> > the elements I want to combine (merge).
> > Now I'm wondering how to continue.
> >
> > To launch a model merge I need the ".eml" that tells epsilon the 
> > source (base), the aspect, and the target.
> > I guess I can add the ".modelink" (actually, the model with the 
> > relationships resulting from it) as input, and according to the 
> > relationships modeled in it make the ".eml" merge elements from A 
> > with elements from B into C. Am I right?.
> >
> > However, I'm not  sure on what to do with the ".ecl" matching.
> > Do I have to make rules for matching elements in Model A with 
> > elements in Model B?, or for matching elements in Model A with 
> > elements in Model C, and then rules for matching elements in Model B 
> > with elements in Model C?.
> >
> > Which is the correct strategy to make such a composition?.
> > Thanks in advance.
> > Regards,
> >             Juan Pedro