Re: Subprogram Renaming

[ncohen@watson.ibm.com (Norman H. Cohen)]

In article <316E12F2.37BC@ehs.ericsson.se>, Jonas Nygren
<ehsjony@ehs.ericsson.se> writes: 

|> >    package Integer_Dequeues is
|> >       type Dequeue_Type is private;
...
|>
|>        procedure Remove_All (Dequeue: in out Dequeue_Type);
|>
|> >    private
|> >       type Dequeue_Type is ...;
|> >    end Integer_Dequeues;
|> >
|> >    with Integer_Dequeues;
|> >    package Integer_Stacks is
|> >       type Stack_Type is private;
...
|>
|>        procedure Remove_All (Stack: in out Stack_Type);
|>
|> >    private
|> >       use Integer_Dequeues;
|> >       type Stack_Type is new Dequeue_Type;
...
|>
|>        procedure Remove_All (Stack: in out Stack_Type)
|>           renames Remove_All; -- Does not work,
|>                               -- Gnat e.g. creates a recursive call (reported)
|>
|> >    end Integer_Stacks;

The explicit declaration of Remove_All in the visible part of
Integer_Stacks hides all homographs later in the same declaration, and
the version implicitly declared after the derived-type declaration is a
homograph of the explicitly declared version.  Thus you're trying to
rename the explicitly declared Remove_All as itself.

Here's an ugly solution: 

    package Integer_Stacks is
       type Stack_Type is private;
       ...

       procedure Remove_All (Stack: in out Stack_Type);

    private

       package Inner is
          type Stack_Parent_Type is new Integer_Dequeues.Dequeue_Type;
          procedure Parent_Remove_All
             (Stack: Stack_Parent_Type) renames Remove_All;
          ...
       end Inner;

       type Stack_Type is new Inner.Stack_Parent_Type;

       procedure Remove_All (Stack: in out Stack_Type)
          renames Parent_Remove_All;
          -- Inherited from Inner.Remove_All

       ...

    end Integer_Stacks;

At least the ugliness is hidden in the private part and has no runtime
overhead.

--
Norman H. Cohen    ncohen@watson.ibm.com