Data.OpenWitness.Exception

Documentation

data Exn e

A key to match exceptions. The type variable is the data the exception carries.

Instances

TestEquality * Exn

Methods

testEquality :: f a -> f b -> Maybe ((Exn :~: a) b)

declexn :: TypeQ -> Q Exp

Template Haskell function to declare Exn exception keys.

throw :: Exn e -> e -> a

catch :: IO a -> Exn e -> (e -> IO a) -> IO a