Re: ada95 and uml

[Simon Wright <simon@pushface.org>]

Robert Palasek <bobpalasek@home.com> writes:

> "Riehle, Richard" wrote:
> 
> > From my study of UML and my knowledge of Ada, I have concluded
> > there is a substantial linguistic discontinuity.  Ada has a rich
> > model of program development that cannot be > completely represented
> > with UML.  Translating from UML to Ada or Ada to UML is guaranteed
> > to lose something in the translation.
> 
> I know a little about each, but am not an expert yet with either.
> 
> But I don't understand the idea that you are supposed to be able to
> generate one from the other.  That seems wrong and misguided to me.
> 
>  A model is an abstraction that carries some proper subset of
> salient points of the thing being modeled.  For it to be useful, the
> model has to leave other stuff out.  If it doesn't leave anything
> out, it's just an alternate representation.

True; model + translation rules -> code. This is possible provided
your model is expressed with the precision required by the translation
rules[1].

This has been a principle of Shlaer-Mellor Recursive design for a
while now (unfortunately the book hasn't come out).

You can get a commercial UML->Ada generator now from Aonix that does
this (for code frameworks only). I'm sure there are others, perhaps
not for Ada!

What you can't reasonably expect to do is to take the result of such a
code-generation, change it, and round-trip back to the model. No great
loss (IMO).

[1] As a simple example, you might have to specify role names for each
end of an association.