Re: generic packages

[adam@irvine.com (Adam Beneschan)]

Sami Evangelista <sami.evangelista@wanadoo.fr> wrote in message news:<3D2D8B01.9040303@wanadoo.fr>...
> thank you for your response, but does the following code compile?
> 
> =======================================================
> --file generic_set.ads
> 
> generic
>       type Element is private;
>       with function "=" (E1, E2 : in Element) return boolean;
> package Generic_Set is
>       type Set_Record is private;
>       type Set is private;
>       generic
>            with package a_set is new generic_set(<>);
>            with package b_set is new generic_set(<>);
>            with function a_to_b(A : in a_set.element) return 
> 
>                                                b_set.element;
>       function a_set_to_b_set(the_set : in a_set.set) return b_set.set;
> 
> 
> private
>       type Set is access Set_record;
>       type Set_record is record
>          El : Element;
>          Others_Els : Set;
>       end record;
> end Generic_Set;
> =======================================================
> 
> Sami Evangelista

The code, as you've written it, is illegal.  Within the declarative
region of Generic_Set, if you use the name Generic_Set, it denotes the
*current* *instance* of the generic, rather than the generic itself. 
Thus, since Generic_Set doesn't denote a generic in this context, it
can't be used where a generic is expected in this formal package
declaration:

    with package a_set is new generic_set(<>);

See 8.6(18), 12.1(11).

				-- Adam