Be careful, though. This only works if there's a single constructor for your exception type. If there are multiple, you should write it like this:
thing_to_try `catch` \(e :: MyErrorType) -> case e of MyError1 _ -> ..; MyError2 _ -> ... If you write `catch` (MyError1 ...) and a MyError2 is thrown, you will get a pattern match error exception. If you want to catch multiple exceptions (of different type) at once, use the "catches" combinator. 2008/11/22 Ross Mellgren <[EMAIL PROTECTED]>: > I think catch is now basically what catchJust was -- you can just do > >> thing_to_try `catch` (\ (ErrorCall s) -> putStrLn s) > > and it will only catch ErrorCall exceptions. > > -Ross > > > David F. Place wrote: >> >> Hi, All. >> >> I am trying to understand the new exceptions package in base-4 >> Control.Exceptions. The documentation for catchJust is the same as in >> Control.OldException including this example: >> >> result <- catchJust errorCalls thing_to_try handler >> >> Control.OldException provides the predicate errorCalls, but the new one >> does not. I don't see how to write it. >> >> Thanks for reading. >> >> Cheers, >> David >> >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > -- Push the envelope. Watch it bend. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
