Re: 'withing' problem

[Simon Wright <simon@pushface.org>]

"Matthew Heaney" <mheaney@on2.com> writes:

> "Simon Wright" <simon@pushface.org> wrote in message
> news:x7vu1w2bil4.fsf@smaug.pushface.org...
> > "Matthew Heaney" <mheaney@on2.com> writes:
> > I think the thing I find most awkward is the asymmetry here.
>
> If you have a cycle, you only have to break the cycle in one place.  I
> arbitrarily picked the Patient type.
>
>
> > When you
> > look at a model (UML I mean, of course), how are you going to know
> > which way to jump?
>
> I don't understand your question.

I'm presuming that most of us start from some sort of visual model:

 +--------------------+                            +-------------------+
 |                    | 1                     0..n |                   |
 |      Doctor        |----------------------------|     Patient       |
 |                    |           treats           |                   |
 +--------------------+                            +-------------------+

I think that people looking at this model, perhaps for the purpose of
maintaining code written to implement it, need to have a very clear
idea of how the code will look.

It's a Bad Thing if you need to make arbitrary decisions to break
cycles.

What would be even worse would be to have a framework code generator
that applied heuristics to break cycles. I imagine that it wouldn't
take much for such heuristics to make the opposite decision for minor
model changes (remember that very few models are as simple as this
one!)