Re: generics in Ada 83

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

"REH" <spamjunk@stny.rr.com> writes:
> Martin Dowie wrote:
>> package A is
>>     type A_T is private;
>>     procedure Y (Z : A_T);
>> private
>>     type A_T is new Integer;
>> end A;
>>
>> generic
>>     type X is private;
>>     with procedure Y (Z : X) is <>;
>> package B is
>> end B;
>>
>> with A; use A;
>> with B;
>>
>> package C is
>>     new B (A_T);  -- Picks up 'Y' by default
>>
>> Cheers
>>
>> -- Martin
>
> That seems reasonable.  Two questions:
> 1) If I have Y1 through Yn, Do I define the ones I care about when I
> instantiate B or do I define then in C, before B?

If there are several Y's to choose from, you must choose at the point
of instantiation of B:

with A, B;
package C is new B (X => A.A_T, Y => A.Yn);

> 2) is there a way to avoid having to include A?

C must see the type and procedure passed to it as actual generic
parameters, so there I can think of no way to avoid withing A.

-- 
Ludovic Brenta.