Re: Why should the value for a discriminant be static?

[Niklas Holsti <nobody@nowhere.fi>]

Jeffrey Carter wrote:
> Niklas Holsti wrote:
> 
>> Now then, that's rather harsh. It's certainly legal Ada; if you think
>> its philosophically faulty, you are entitled to your opinion and I am
>> entitled to disagree; if you think its faulty because it leads to
>> practical problems, the problem is just with the requirement for
>> static discriminants in aggregates -- which is what this thread is
>> about.
> 
> 
> Not at all. There's a software engineering principle that one thing 
> should serve one purpose, and this violates that: it serves both to 
> identify the 2 classes and to provide the specific information for each 
> class.

So the "fault" is philosophical. From your interpretation of that
principle, you could argue against any use of "derived properties
of objects", and insist on a separate component to hold each such
derived property. Not attractive to me, but as I said, we can
disagree on what is desirable, even if we agree that the current
Ada rules are asymmetrical in this area.


-- 
Niklas Holsti
Tidorum Ltd

niklas holsti tidorum fi
       .      @       .