Re: urgent question - generics

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

On Mon, 03 Sep 2007 17:08:28 +0300, Niklas Holsti wrote:

> It's still unclear to me if the OP wants the parameterless 
> procedure (Proc, above) to be a generic parameter (as in Pascal's 
> solution) that is associated with an actual procedure when the 
> generic function is instantiated, or a non-generic parameter to the 
> (generic) function that is associated with an actual procedure when 
> an instance of the generic function is called (as in "anon's" 
> non-generic solution where only the address of the procedure was used).

I doubt that the exercise would use the word "generic" in this case. Just:

   function Bar (...; Foo : access procedure) return ...; -- Ada 2005

   type Foo_Ptr is access procedure;
   function Bar (...; Foo : Foo_Ptr) return ...; -- Ada 95

But OK, in order to add a bit more confusion (:-)), there also could be a
generic function which formal generic parameter is an instance of a generic
parameterless procedure. Here it goes:

   generic
      ...
   package I_Have_A_Foo is -- We need an envelope package
      procedure Foo;
   end I_Have_A_Foo;

   generic
      with package Here_Is_My_Foo is new I_Have_A_Foo (<>);
   function Bar (...) return ...;

Moreover, there could be a generic function which formal generic parameter
is inherited from a generic ancestor:

   generic
      with procedure Foo;
   package I_Take_Foo is ... end I_Take_Foo;

   generic
   function I_Take_Foo.Bar (...) return ...;

Being a child of I_Take_Foo, Bar receives Foo from its parent. I hope that
would suffice to perplex the prof... (:-))

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