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use of libraries [message #930706]

Tue, 02 October 2012 11:02

C. Cuauhtemoc
Messages: 6
Registered: September 2012
Location: paris

Junior Member

Hello,

I'm trying to modularize my transformation code into sorted libraries.
Separating helpers and queries works but i can't separate a call to a mapping and its definition. When i do it, it tells me that it cannot find operation.
Is there a way to tell to the interpretor that it has to look into the library?

thanks,

Cuauhtemoc.

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Re: use of libraries [message #930733 is a reply to message #930706]

Tue, 02 October 2012 11:31

Ed Willink
Messages: 3159
Registered: July 2009

Senior Member

Hi

The OMG specification on the packaging of transformations is vague and I
have no idea what QVTo does.

You could try referencing as MyLibrary::MyTransformation

Regards

Ed Willink

On 02/10/2012 17:02, castellanoscuauhtemoc@xxxxxxxx cuauhtemoc wrote:
> Hello,
> I'm trying to modularize my transformation code into sorted libraries.
> Separating helpers and queries works but i can't separate a call to a
> mapping and its definition. When i do it, it tells me that it cannot
> find operation.
> Is there a way to tell to the interpretor that it has to look into the
> library?
>
> thanks,
> Cuauhtemoc.
>

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Re: use of libraries [message #930804 is a reply to message #930733]

Tue, 02 October 2012 12:56

Fabio L. S.
Messages: 15
Registered: July 2010
Location: Brazil

Junior Member

Hi Cuauhtemoc;

For me, a simple "import" works fine. Here it is a small example based on the SimpleUML to RDB example (there are two packages, p1 and p2):

import p2.Map;

modeltype UML uses 'http://www.eclipse.org/qvt/1.0.0/Operational/examples/simpleuml';
modeltype RDB uses 'http://www.eclipse.org/qvt/1.0.0/Operational/examples/rdb';

transformation Simpleuml_To_Rdb(in uml : UML, out RDB);

main() {
	uml.rootObjects()[UML::Model]->map model2RDBModel();
}

mapping UML::Model::model2RDBModel() : RDB::Model {
	name := self.name;
	schemas := self.ownedElements[UML::Package]->asOrderedSet()->map package2schema();
}

library Map;

modeltype UML uses 'http://www.eclipse.org/qvt/1.0.0/Operational/examples/simpleuml';
modeltype RDB uses 'http://www.eclipse.org/qvt/1.0.0/Operational/examples/rdb';

mapping UML::Package::package2schema() : RDB::Schema 
{
	name := self.name;
}

Regards;

Fabio Levy Siqueira

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Re: use of libraries [message #931756 is a reply to message #930804]

Wed, 03 October 2012 09:45

C. Cuauhtemoc
Messages: 6
Registered: September 2012
Location: paris

Junior Member

Thanks,
it works very well thank you!!
The error it was that i was trying to import transformation mapping, not librarry.
Do you know how to have an superimposition behaviour?
I know that it is not included in the standard but this feature is powerfull for maintainablity and evolability of transformation.
Otherwise i would make wrappers.

Thanks;

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Re: use of libraries [message #931795 is a reply to message #931756]

Wed, 03 October 2012 10:31

Fabio L. S.
Messages: 15
Registered: July 2010
Location: Brazil

Junior Member

Sorry, I have no clue... I'm not familiar with the concept of superimposition. If you describe a concrete example, maybe someone can help.

Regards;

Fabio Levy Siqueira

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Re: use of libraries [message #932595 is a reply to message #931795]

Thu, 04 October 2012 04:53

C. Cuauhtemoc
Messages: 6
Registered: September 2012
Location: paris

Junior Member

In fact, I'm trying to give to my transformation a wrapper pattern structure, that ease adding functionnalities to my transformation.
There are disjuncts mappings that decide which functionnality to use. The point is that each library has to be able to call the wrapper, but the wrapper import them and the wrapped functionnalities has to import the wrapper to call it. So I have some cyclic dependencies.
Superimposition allow to implement this kind of structure. I'm wondering if there is a way to implement it in separated libraries.

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Re: use of libraries [message #932601 is a reply to message #932595]

Thu, 04 October 2012 04:57

Ed Willink
Messages: 3159
Registered: July 2009

Senior Member

Hi

Cyclic dependencies are often challenging if not actually ill-formed.

Naively it would seem to me that you have a modularization problem if
your wrappers are not almost dependency-free.

Regards

Ed Willink

On 04/10/2012 10:53, C. Cuauhtemoc wrote:
> In fact, I'm trying to give to my transformation a wrapper pattern
> structure, that ease adding functionnalities to my transformation.
> There are disjuncts mappings that decide which functionnality to use.
> The point is that each library has to be able to call the wrapper, but
> the wrapper import them and the wrapped functionnalities has to import
> the wrapper to call it. So I have some cyclic dependencies.
> Superimposition allow to implement this kind of structure. I'm
> wondering if there is a way to implement it in separated libraries.

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Re: use of libraries [message #932780 is a reply to message #932601]

Thu, 04 October 2012 08:23

C. Cuauhtemoc
Messages: 6
Registered: September 2012
Location: paris

Junior Member

Simply, I have a library A (the wrapper) which import library B (the wrapped), but library B needs to call the wrapper.
I didn't understand what a module realy is, and how to use it. "Its a unit containing a set of operations and types defined to operate on models", but is it a transformation, a library? It is not very clear to me.
If you can enlight on this point.
Thanks

Cuauhtemoc

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Re: use of libraries [message #932912 is a reply to message #932780]

Thu, 04 October 2012 11:06

Fabio L. S.
Messages: 15
Registered: July 2010
Location: Brazil

Junior Member

Hi Cuauhtemoc;

Maybe I did not understand your question, but in the QVT specification a library and a transformation are modules (specializations of the "module" metaclass) (see page 78). I don't know why the "module" metaclass is not abstract, i.e., what is a module that is neither a library nor a transformation...

Regarding your problem, try to reorganize your libraries in order to avoid Library B calling Library A ("wrapped" calling the "wrapper"). As Ed commented, cyclic dependencies are often an indication of an inadequate organization (not cohesive enough). Ask yourself if it is really necessary. If it *really* is, a simple solution is to move the A's mappings & queries used by B to another Library (C, for example) and make A and B import it.

Regards;

Fabio Levy Siqueira

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