Re: Calling generic children from their parent?

[Tucker Taft <stt@averstar.com>]

rcollinson@my-deja.com wrote:
> ...
> My problem is that I TRY to instantiate a generic
> child unit inside the body of the parent and it
> will not compile.  The text Rendezvous with Ada 95
> states this is possible on page 337 but I have
> been unable to make it work.  (On a slightly
> different subject, why in the example on page 337
> do they WITH and ELABORATE Generic_Parent.Child in
> the last exerpt?)

If you can post a small self-contained example with the
accompanying error message you received from the compiler,
I suspect someone could quickly point out the solution to your problem.

Here is an example that should work:

   generic
   package P is 
       procedure Dummy;
   end P;

   generic
   package P.C is
       type T is null record;
   end P.C;

   with P.C;
   package body P is
      package Child is new P.C;
      type NT is new Child.T;
      procedure Dummy is
          X : NT;
      begin
          null;
      end;
     -- ...
   end P;

Note that you normally have to instantiate all ancestors
of a child of a generic before instantiating the child.  
However, when inside the parent generic, the name of the 
parent generic itself represents the "current instance",
and hence you don't need to instantiate the parent generic inside
itself to be able to instantiate the child.

> Roger

-- 
-Tucker Taft   stt@averstar.com   http://www.averstar.com/~stt/
Technical Director, Distributed IT Solutions  (www.averstar.com/tools)
AverStar (formerly Intermetrics, Inc.)   Burlington, MA  USA