]> From: Chris Hecker <checker@d6.com> > >You could tell the same for stack overflow and some other kinds of > >exceptions. OCaml uniformly treat failures as exceptions, and that's the > >right thing to do. But catching exceptions with _ , without even printing > >them, is not the "right thing" and is definitly huge pain and error prone. > > I totally disagree about assert being the same as a stack overflow in > nature, but more importantly, you're ignoring the lessons learned from C++ > and Java on the exception specification front. You just don't know what > exceptions code you call in a real program will throw in general. There > are plenty of times when you want to try something at runtime and just bail > if it doesn't work, and you don't care about the specifics of why it didn't > work. A single "with _" will mask any assertions living below it, which > seems to me to be a bad thing since by definition an assert is a > development debugging tool. Assert should just blow up, like in C (at > least as an option). You shouldn't have to remember to put a "with" clause > in for it. But you might really want to catch assert failures! For instance if you're building a debugging tool. So the problem rather stems from the fact exn is a flat type. You have no way to specify "categories" of exceptions, like you would do in Java. Also you could view the behaviour of [try ... with _ -> ...] as dangerous, and prefer a different behaviour. Unfortunately, _ is expected to mean any exception, and it would be difficult to make it mean something else. Note that it's easy enough to define a class of exceptions as fatal: let check_fatal = function Assert_failure _ | Stack_overflow | Match_failure _ as exn -> raise exn | _ -> ();; Then you just have to write try ... with exn -> check_fatal exn; ... You can certainly use camlp4 to do this automatically. Alternatively, one could argue that this is similar to the ctrl-break problem: [Sys.catch_break] allows you to decide whether you want it to be catchable or not. Unfortunately this would imply some extra cost for [raise]. Jacques ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners