Re: Structured exception handling should be a core module.

[Peter Scott]

At 06:48 PM 8/24/00 -0600, Tony Olekshy wrote:
>Peter Scott wrote:
> >
> > At 06:06 PM 8/24/00 -0600, Tony Olekshy wrote:
> > >
> > >In fact, not only would I be pleased and honoured to author the
> > >Perl 6 core Try.pm module, I'm already working on a Perl 5 standard
> > >reference implementation.
> >
> > >Peter, I think we should make this approach more clear in RFC 88.
> >
> > I'm not convinced that this can totally be implemented in a
> > module.  Particularly if RFC 151 passes :-)
>
>I've read 151 a few times, and I don't understand how it can impact
>the implementation of RFC 88 as a module.  Please explain.

If $@ and $! are merged, then in code like

         try {
                 system_call_that_fails();
                 more_stuff_that_succeeds();
         }
         finally {
         }

does the finally block think there is a current exception or not?  $! was 
set by the failed system call, but nothing died or threw.  If $@ is put 
into $! instead, how does the finally block know that it's not an 
exception?  ! ref($!) ...?
--
Peter Scott
Pacific Systems Design Technologies