open-witness-0.4: open witnesses
Data.OpenWitness.Exception
Synopsis
data Exn e #
A key to match exceptions. The type variable is the data the exception carries.
Instances
Methods
testEquality :: f a -> f b -> Maybe ((Exn :~: a) b) #
declexn :: TypeQ -> Q Exp #
Template Haskell function to declare Exn exception keys.
Exn
throw :: Exn e -> e -> a #
catch :: IO a -> Exn e -> (e -> IO a) -> IO a #