Control.Exception

[Sigbjorn Finne]

On 11/3/2008 07:34, Jason Dagit wrote:
> ....
>
> Ah, but I had one more question that I don't think anyone has answered
> yet.  That is, how to deal with multiple types of exceptions.
> Suppose, as a concrete example, that I was looking out for both
> ExitCode and PatternMatchFail exceptions.  Maybe I'm being naive, but
> it seems like I'm in that situation again where I have to catch all
> and then check if fromException succeeds on either PatternMatchFile or
> ExitCode types.  And then throw if it both give Nothing?
>
>   
One way to do this now is to use Control.Exception.catches:

 catches :: IO a -> [Handler a] -> IO a
 data Handler a where
    Handler :: forall a e. (Exception e) => (e -> IO a) -> Handler a

--sigbjorn