Re: Comparison : Ada and UML (comparison… indeed)

[Matteo Bordin <matteo.bordin@gmail.com>]

> > I personally don't see much sense in trying to semantically merge the
> > HOOD modeling approach (based on the notion of static "class"
> > instance) with the UML one (based on the dichotomy between classifiers
> > [classes] and typed elements [objects and class members]).
>
> There is no UML modeling approach. UML is a language (used by various
> modelling approaches, granted). If the purpose of UML is to reduce the
> confusion by standardizing boxes and arrows, why not use it on HOOD? It
> will make a HOOD design more understandable to people who are not used
> to HOOD diagrams.
>
> > Decorating
> > a UML class with an <<HOOD_Active_Object>> stereotype (or whatever)
> > does not mean much: a UML class needs to be instantiated to have a run-
> > time executable semantics, while a HOOD object doesn't. This
> > inconsistency has a lot of repercussions on several model elements and
> > on several levels.
>
> UML claims that it can represent any design method, thanks to stereotypes...

I think that what you really mean is to support the HOOD method using
UML. But to do so you would need to define a mapping between the
elements which the HOOD method requires to manipulate and UML
elements. This is not necessary straightforward/natural.

Also note that UML profiles allow to extend/constraint the UML
metamodel, but cannot contradict it.

> > Of course, you can always come up with a GUI intelligent enough to
> > hide the semantic inconsistency between the two languages,
>
> HOOD is not a language, but primarily a design method. Diagrams are just
> used as a representation of the result of a design.

You're right, sometimes I forgot that HOOD "models" does not have any
semantics... whatever UML box and arrow you pick, it will work...

> > but the
> > underlying UML model (supposing models are serialized to UML and not
> > to proprietary formats)
>
> Note that HOOD defines a portable, open format for representing HOOD
> designs - and it did that long before UML.

I was referring to the fact that a UML-like graphical front-end does
not imply a UML-compliant back-end semantics. Visio or PowerPoint may
be used to provide as UML front-end, but they do not produce any
usable model. BTW, HRT-UML (like HRT-UML/RCM) was not compliant with
UML neither in the graphical front-end nor back-end.