Re: Generic procedures and their parameters

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Wed, 06 Sep 2006 18:35:58 +0200, Georg Bauhaus wrote:

> On Wed, 2006-09-06 at 17:09 +0200, Dmitry A. Kazakov wrote:
>> On Wed, 06 Sep 2006 16:14:07 +0200, Maciej Sobczak wrote:
>> 
>>>> Why is that shaky?  Integer IS ordered.
>>> 
>>> Is it also tagged? Do you want it to be?
>> 
>> Not Integer, but Integer'Class.
>> 
>>> Integer is not only Ordered. It's also Summable, Subtractable, 
>> [...]
>> 
>> Yes, it is called multiple inheritance.
> 
> A {PropA,PropB,...}able Integer has multiple interfaces,
> can act as any of them, etc, ok, but I think MI is inheritance
> of data as well, in the vernacular. Are you perhaps thinking
> of something like "aspect interfaces"?

I remember it is was a buzz word 2-3 years ago. (:-))

I don't think it makes any sense to separate interface and implementation
inheritance.

OK, in practice, there might be a granularity associated with the
visibility issues. For Ada it would mean that you could publicly inherit
from an interface and privately choose whether you inherit the
implementation as well, or rather provide a completely new one. And,
reverse, you don't inherit from interface, but, privately, do from the
implementation. The later is widely used in Ada (it is type X is private;)

But this all is independent on the question whether interface and
implementation inheritances are different things. They are not. 

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de