Re: tagged types extensions - language design question

[Laurent Guerby <guerby@acm.org>]

"Vladimir Olensky" <vladimir_olensky@yahoo.com> writes:

> The question is :
> 
>    Why in Ada it is  not allowed to extend both public
>  and private part of the tagged type at one step ( using
>  kind of syntax as in the following example ):
> 
> package P is
> 
>    type T is tagged private;
> 
>    type T1 is new T with
>       record with private
>                  something: some_type;
>       and record;
> 
> private
> 
>    type T is tagged with
>       record
>            ID : Integer;
>       end record;
> 
>    type T1 is new T with
>       record
>           thing : some_other_type;
>       end record;
> 
> end P;

What about:

   type T1_Private is private;

   type T1 is new T with  record
      something_public  : some_type;
      something_private : T1_Private;
   end record;

private

   type T1_Private is record
      -- whatever...
   end record;

>     It would be interesting to know what were
> the reasons not to allow to have BOTH a record
> extension AND a private extension at the same time.

Looks like it's easy to emulate, at least in the simple case you
provided.

> Regards,
> Vladimir Olensky

--LG