[news.eclipse.modeling.m2m] Re: [QVTO] Executing OCL queries

[christian.saad@xxxxxxxxxxxxxxxxxxxxxxxxxx (C. Saad)]

Hi Radek,

thanks for your quick answer! Ok, so I guess there is no easy way around 
this problem, but I'm not willing to let go just yet ;)
Would it be possible as a workaround, e.g. to define kind of a pseudo-QVT 
transformation that in reality only executes the query (unfortunately my 
knowledge of QVT is very limited) or could the I-OCL interpreter be 
somehow "exported" as a separate plugin?

Regards,
Chris

radek dvorak wrote:

> Hi Chris,

> We do not support standalone Imperative OCL directly, so by using QVTO  
> component
> you can't parse and evaluate Imperative OCL expressions.

> I agree that separation of this functionality seems natural and we  
> definitely
> are going to do some steps in this direction, just to get a cleaner design.
> Anyway, it's unlikely that this will appear as API of QVTO in Helios.

> What we do support is calling into QVT libraries from plain OCL, by using
> a special OCL environment factory. It's possible to separate the
> complex logic, which can be expressed more effectively in QVT queries and
> reused in standard OCL expressions.

> Currently, it's not part of the QVTO API, but we will expose this as API in
> Helios, as it's pretty handy.

> Regards,
> /Radek



> On Tue, 01 Sep 2009 16:55:15 +0200, C. Saad  
> <christian.saad@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

> > Hi everyone,
> >
> > I'm using OCL to carry out some calculations on EMF models. This works  
> > quite well, however I'd like to replace essential OCL with imperative  
> > OCL because its additional expressions would enable the definition of  
> > more elaborate queries (but I don't need or want query-external  
> > side-effects nor any other QVT-related functionality).
> >
> > Is there a way to easily switch from standard OCL to the imperative OCL  
> > implementation of the QVT project? I tried some things, e.g. replacing  
> > the environment factory...
> >
> > OCL OCL_ENV = OCL.newInstance(QvtOperationalEnvFactory.INSTANCE);
> >
> > ..but unfortunately, without any success.
> >
> > Any help would be highly appreciated :)
> >
> > Regards,
> > Chris