Re: Pondering what rationale behind record type

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

On Tue, 10 May 2011 00:03:37 +0200, Georg Bauhaus wrote:

> First, in the phrase "end X", the "X" part can usually be omitted.

That is another fix to do: a default profile which would forbid omitting
the name. I saw no Ada program in my life which omitted names in the ends.

> So whenever we put "record" (or "case", or "if", etc) after an "end",

These are anonymous constructs. The only reason why record bracket should
not contain its name is when there is no name, e.g. as Randy has pointed
out, in an anonymous record type. They are illegal in Ada, but an imaginary
example could be:

   function Get_Token (File : File_Type) return
      (Matched : Boolean; Length : Positive) record
         case Matched is
            when True => Token : String (1..Length);
            when False => null;
         end case;
      end record;

The result is this anonymous record:

type <anonymous> (Matched : Boolean; Length : Positive) is record
   case Matched is
      when True => Token : String (1..Length);
      when False => null;
   end case;
end record;

We could continue the exercise with other types:

   function Get_Handle  (...) return
      new Ada.Finalization.Controlled with record ... end record;

   function Get_List  (...) return
      array (Positive range <>) of Element;

Do you like it? (:-))

> Consequently, how about this addition to the syntax of record
> declarations:
> 
>     type R is
>       record
>          ...
>       end record R;
> 
> ?

Shudder.

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