Walter,

could AccessViolations and other OS/CPU exceptions be a different sub class of Exception so they can be caught without having to blanket catch Exception;

I quite like the Java Exception inheritance tree;

Throwable <-Exception <- RuntimeException  <- ArrayIndex etc etc things you
might want to catch
Throwable <- Error <- Things you normaly would not want to catch.

this is partly because I'm playing with mem mapping a file (readonly) so
want to be able to catch writes without other exceptions
and partly because I think there should be a
try { ... } catch ( Foo e ) { ... }
that lets you catch a range of exceptions such as just D runtime exceptions,
just CPU excepions, just null pointer exceptions
or just non program error (i.e. file io) exceptions  etc.

You're probably right. -Walter

"Mike Wynn" <mike.wynn@l8night.co.uk> wrote in message news:b4e03m$ssh$1@digitaldaemon.com...
> Walter,
>
> could AccessViolations and other OS/CPU exceptions be a different sub
class
> of Exception so they can be caught without having to blanket catch Exception;
>
> I quite like the Java Exception inheritance tree;
>
> Throwable <-Exception <- RuntimeException  <- ArrayIndex etc etc things
you
> might want to catch
> Throwable <- Error <- Things you normaly would not want to catch.
>
> this is partly because I'm playing with mem mapping a file (readonly) so
> want to be able to catch writes without other exceptions
> and partly because I think there should be a
> try { ... } catch ( Foo e ) { ... }
> that lets you catch a range of exceptions such as just D runtime
exceptions,
> just CPU excepions, just null pointer exceptions
> or just non program error (i.e. file io) exceptions  etc.
>
>
>
>

Despite OO being a stillborn concept, especially the way Java, .NET and D derive everything from a root object, there is one place where it is not only harmless but +vely useful: exceptions. Every exception should be in an inheritance tree.

Also, I agree that one of the (extremely) few good things about Java is the exception model. Not like the inconsistent mess of .NET. Let's do something like that with D.

I've just realised that, for some stupid reason, one of the exceptions I did for a D library didn't declare a parent class. I think I assumed it would derive automatically from Exception - barmy! I'd better go and fix ...

(sheepish grin)

Matthew


"Walter" <walter@digitalmars.com> wrote in message news:b7kf9c$2df6$2@digitaldaemon.com...
> You're probably right. -Walter
>
> "Mike Wynn" <mike.wynn@l8night.co.uk> wrote in message news:b4e03m$ssh$1@digitaldaemon.com...
> > Walter,
> >
> > could AccessViolations and other OS/CPU exceptions be a different sub
> class
> > of Exception so they can be caught without having to blanket catch Exception;
> >
> > I quite like the Java Exception inheritance tree;
> >
> > Throwable <-Exception <- RuntimeException  <- ArrayIndex etc etc things
> you
> > might want to catch
> > Throwable <- Error <- Things you normaly would not want to catch.
> >
> > this is partly because I'm playing with mem mapping a file (readonly) so
> > want to be able to catch writes without other exceptions
> > and partly because I think there should be a
> > try { ... } catch ( Foo e ) { ... }
> > that lets you catch a range of exceptions such as just D runtime
> exceptions,
> > just CPU excepions, just null pointer exceptions
> > or just non program error (i.e. file io) exceptions  etc.
> >
> >
> >
> >
>
>