Re: Your wish list for Ada 202X

["Randy Brukardt" <randy@rrsoftware.com>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:n89glydkjsjz.17f34lyu7q1j4.dlg@40tude.net...
> On Thu, 10 Apr 2014 17:08:37 -0500, Randy Brukardt wrote:
>
>> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
>> news:17twpp4p8u7o$.1idvzaaio4f3t$.dlg@40tude.net...
>> ...
>>> It is as unrealistic as throwing out all numeric types and using 
>>> arbitrary
>>> precision arithmetic instead. It simply does not work for real-life
>>> applications.
>>
>> Huh? It's exactly how I would define Root_Integer'Class if we had such a
>> thing.
>
> And no any program needs both Integer_16 and Unsigned_8 anyway. Right?
>
>>>> Ambiguous? That's the idea -- most consumers of strings don't care 
>>>> anything
>>>> about the properties of the string, just the sequence of code points 
>>>> that it
>>>> represents.
>>>
>>> Class-wide operations are overloaded, which is why.
>>
>> Overloaded with what?
>
> With operations of other classes especially operations of subclasses.
> Return a class-wide object is a nightmare. I had a lot of problems with
> class-wide operations in recent projects. It is not only ambiguity, but
> also a hell of type conversions and other tricks required when you have to
> return a class-wide. It works only on paper.

Then OOP doesn't work, because that's the only sensible use of OOP (to get 
"generic" operations while still preserving individual characteristics). 
Otherwise, you might as well build a set of unrelated types and use 
generics.

I can believe that there are problems inhibiting the use of class-wide types 
in this way, but those are precisely the problems that the language needs to 
address. Without class-wide programming, OOP is simply a waste of effort 
(and runtime).

                                      Randy.