Re: A bad counterintuitive behaviour of Ada about OO

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

On Fri, 08 Aug 2014 12:01:48 +0200, J-P. Rosen wrote:

> Le 08/08/2014 11:13, Dmitry A. Kazakov a écrit :
>> How mathematics may not apply to the elementary types like Integer?
> Because computer integers are not the same as mathematical ones, and the
> way they are used are different.

Interesting, it was always OO proponents' argument that numbers are not
numbers.
 
> Moreover, classification is used in mathematics for the theory of
> numbers, which is not relevant to practical usage of numbers.

Having integers ordered is unpractical? Being them additive has no usage?

>> Do you propose not to formalize "some features"? This is not how Ada
>> generics work anyway. "Some features" are formalized in Ada through formal
>> generic parameters. The only difference to classes is that classes do that
>> through types, while generics do in an untyped manner.
> 
> And those types must be related through inheritance, while generics may
> be instantiated on types that have no conceptual relationship.

I don't know which relationships are "conceptual" and which are not.

generic
   type Element_Type is private;
   with function "<" (Left, Right : Element_Type) return Boolean is <>;
   with function "=" (Left, Right : Element_Type) return Boolean is <>;
package Ada.Containers.Ordered_Sets is

Isn't all types acceptable as Element_Type a "conceptual" class?

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