Re: Sugestion to Multiple Inheritance

[lutz@iks-jena.de (Lutz Donnerhacke)]

* Stephen Leake wrote:
>lutz@iks-jena.de (Lutz Donnerhacke) writes:
>> >> They do not need to be types at all. They are abstactions => interfaces.
>> >> Example: A describes a sort algorithm. B describes stableness. C describes
>> >> in-place-ness. D describes stable, in-place sort algorithms.
>> >
>> >Well, if they don't have to be types, you can easily do it in Ada. But
>> >all your complaints were that it could not be done with abstract Ada
>> >types.
>> 
>> I'm sorry for providing my solutions in the same posting asking for hints.
>> How can this be done easily?
>
>Just write packages A, B, C, D, with appropriate subprogram
>declarations in the spec, and appropriate comments saying what they
>do. Then in the body of D, call the subprograms in B and C as
>appropriate.
>
>The Ada code will _not_ describe the inheritance structure, except in
>the comments. Perhaps that is why you don't want to do this.

Let's try to code this:

package Sorts is
   function Sort (col : Collection) return Collection is abstract;
   procedure Sort (col : in out Collection) is abstract;
end package Sorts;

with Sorts;
package Stable_Sorts is
   function Sort renames Sorts.Sort;
end package Stable_Sorts;

with Sorts;
package Inplace_Sorts is
   procedure Sort renames Sorts.Sort;
end package Stable_Sorts;

with Stable_Sorts, Inplace_Sorts;
package Stable_Inplace_Sorts is
   procedure Sort renames ?;
end package;