[news.eclipse.modeling.gmt] Re: OAW - Type Casting with XTend

[Karsten Thoms <karsten.thoms@xxxxxxxxx>]

You could override your upper() function, assuming a default for non 
MultiplicityElements, then upper() will also be recognized for 
ConnectableElement and if it is at runtime a MultiplicityElement the 
appropriate function will be called.

int upper (MultiplicityElement this) : upper;

int upper (Element this) : 1;


cached int getConnectorCount(uml::ConnectorEnd e) :
 uml::MultiplicityElement.isInstance(e.role) ?
  e.getPartWithPortMultiplicity() * e.upper() *
 (e.role.upper()
    : e.getPartWithPortMultiplicity() * e.upper()


Alexander Nyßen schrieb:
> Yes of course they are not in the same hierarchy, that's why I indeed 
> need the cast!
> Just assume e.role is a Property, which is a ConnectableElement as well 
> as MultiplicityElement.
>
> Best Regards
> Alexander Nyßen
>
>
> "Karsten Thoms" <karsten.thoms@xxxxxxxxx> schrieb im Newsbeitrag 
> news:g3qkt1$njg$1@xxxxxxxxxxxxxxxxxxxx
> > Hi Alexander,
> >
> > you get this error because those types are not in a type hierarchy and 
> > cannot be casted therefore.
> >
> > The type hierarchy is as follows:
> >
> > Element <- NamedElement <- TypedElement <- ConnectableElement
> > Element <- MultiplicityElement
> >
> > You may consult the UML2 superstructure. Seems that the 
> > ConnactableElement's role is not an MultiplicityElement.
> >
> > ~Karsten
> >
> > Alexander Nyßen schrieb:
> > > I have specified the following in my Extension:
> > >
> > > cached int getConnectorCount(uml::ConnectorEnd e) :
> > > uml::MultiplicityElement.isInstance(e.role) ?
> > >  e.getPartWithPortMultiplicity() * e.upper() * 
> > > ((uml::MultiplicityElement)e.role).upper()
> > >     : e.getPartWithPortMultiplicity() * e.upper()
> > > ;
> > >
> > > The cast of e.role into MultiplicityElemenet is acknowledged by the 
> > > OAW environement with the error "cannot cast from 
> > > uml::ConnectableElement into uml::MultiplicityElement". The dynamic 
> > > type of e.role may however by a MultiplicityElement. What am I doing 
> > > wrong?