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[Acceleo] Unable to make a query with collection as return type [message #64963]

Sun, 26 July 2009 08:15

Eclipse User

Hello,

The current acceleo version (2.6.0 with galileo) is not able to compile a
query with a Set as return type.

For example :

[module umlUtils('http://www.eclipse.org/uml2/2.1.0/UML')/]

[query public allAssociations (m : Model) : Set (Association) =
m.allOwnedElements()->select (oclIsKindOf(Association))/]

Says :
Invalid Type:Set (Association)

According to the OMG specification this must be works.

Thanks for your great work on acceleo.

Best regards,
Alexis

Re: [Acceleo] Unable to make a query with collection as return type [message #64975 is a reply to message #64963]

Sun, 26 July 2009 12:58

Eclipse User

Interesting....

If I write :

[query public allAssociations (m : Model) : Association =
m.allOwnedElements()->select (oclIsKindOf(Association))/]

A collection is returned. Is it a standard behavior ?

Regards,

Alexis

Re: [Acceleo] Unable to make a query with collection as return type [message #65089 is a reply to message #64975]

Mon, 27 July 2009 05:51

Eclipse User

Hi,

I think your problem is the same as I reported here:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=262153

It seems that editor and runtime sometimes do no type-checks where you
would expect them. E.g. the following code is working if the package p
contains only classes:

[template public generate(p : Package)]
[for (c : Class | p.ownedType->select(t:Type|t.oclIsTypeOf(uml::Class)))]
[c.genereateClass()/]
[/for]
[/template]

The return type of the the statement
p.ownedType->select(t:Type|t.oclIsTypeOf(uml::Class)) is Set(Type) and not
Set(Class). Still, neither the editor, nor the engine complains. The
correct statement would be
p.ownedType->select(t:Type|t.oclIsTypeOf(uml::Class))->collect(t:Type|t.oclAsType(uml::Class))

By the way: This is a very bloated expression, but I think it cannot be
written in a shorter way using standard OCL. I hope in the next version of
the MTL standard they adopt some shortcuts from QVT-OM. In QVT-OM you can
write p.ownedType[uml::Class] to achieve the same.

Greetings,
Max

Re: [Acceleo] Unable to make a query with collection as return type [message #65156 is a reply to message #65089]

Mon, 27 July 2009 07:09

Eclipse User

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Hi,

> By the way: This is a very bloated expression, but I think it cannot
> be written in a shorter way using standard OCL.

The only shortcuts I can think of for your expression is to make use of
the implicit collect and variables :
p.ownedType->select(oclIsTypeOf(uml::Class)).oclAsType(uml::Class)

That being said, you can take a look at this newsgroup thread
http://www.eclipse.org/newsportal/article.php?id=1885&gr oup=eclipse.modeling.mdt.ocl#1885
for details on why the implementation doesn't check the return type of
these selects.

As for the first query given as an exemple here, I believe Acceleo has
its own issues with parsing parameterized collections (instead of
Set(Association), you could have written 'Set(T)") that we must attend
to. OCL on its side has some opened bugs on such issues that could be
the source of yours : https://bugs.eclipse.org/bugs/show_bug.cgi?id=191819 .

Laurent Goubet
Obeo

Max Bureck a

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