Re: Common exception handling

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

On Tue, 26 Aug 2008 07:43:20 -0700 (PDT), Adam Beneschan wrote:

> On Aug 26, 6:47 am, shaunpatter...@gmail.com wrote:

>> Yeah, it looks like the extra layer of exception handling is the only
>> way. I was hoping I could avoid that if possible.
> 
> No, I don't think it's the only way.  I'm surprised no one has
> suggested this:
> 
>    exception
>       when E : others =>
>          Print_Test (Rec);
>          declare
>              use Ada.Exceptions;
>          begin
>              if Exception_Identity(E) = A'Identity then
>                 ... handling for A
>              elsif Exception_Identity(E) = B'Identity then
>                 ... handling for B
>              etc.
>              else
>                 ... handling for other exceptions you didn't expect,
>                 ... but you certainly need to aware that it could
>                 ... happen
>                 raise;  --maybe
>              end if;
>          end;

Hmm, it looks quite ugly, IMO. Exception handler (case-like) is better
structured, cleaner, and possibly more efficient.

---------
If exceptions were first-class citizens allowed in case statements then:

   exception
      when E : others =>
         Print_Test (Rec);
         case E is            -- This is not Ada, alas!
            when A => ...
            when B => ...
            when others => ...
         end case;

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