ref: 4491fed30b2fceec400a9fd8e4b4349bab180ef6
dir: /lib/Control/Exception.hs/
-- Copyright 2023 Lennart Augustsson
-- See LICENSE file for full license.
module Control.Exception(
catch, try,
throwIO,
Exn(..),
exnToString,
onException,
SomeException,
) where
import Primitives
import Control.Exn
type SomeException = Exn
catch :: forall a . IO a -> (Exn -> IO a) -> IO a
catch ioa hdl = primCatch ioa (hdl . Exn)
try :: forall a . IO a -> IO (Either Exn a)
try ioa = catch (fmap Right ioa) (return . Left)
throwIO :: forall a . Exn -> IO a
throwIO (Exn s) =
let e = error s
in seq e (return e)
onException :: IO a -> IO b -> IO a
onException io what = io `catch` \e -> do _ <- what
throwIO e