diff options
Diffstat (limited to 'Utility/Exception.hs')
| -rw-r--r-- | Utility/Exception.hs | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/Utility/Exception.hs b/Utility/Exception.hs index 13c9d508a..802e9e24b 100644 --- a/Utility/Exception.hs +++ b/Utility/Exception.hs @@ -7,11 +7,25 @@ {-# LANGUAGE ScopedTypeVariables #-} -module Utility.Exception where +module Utility.Exception ( + module X, + catchBoolIO, + catchMaybeIO, + catchDefaultIO, + catchMsgIO, + catchIO, + tryIO, + bracketIO, + catchNonAsync, + tryNonAsync, + tryWhenExists, +) where +import Control.Monad.Catch as X hiding (Handler) +import qualified Control.Monad.Catch as M import Control.Exception (IOException, AsyncException) -import Control.Monad.Catch import Control.Monad +import Control.Monad.IO.Class (liftIO, MonadIO) import System.IO.Error (isDoesNotExistError) import Utility.Data @@ -44,14 +58,20 @@ catchIO = catch tryIO :: MonadCatch m => m a -> m (Either IOException a) tryIO = try +{- bracket with setup and cleanup actions lifted to IO. + - + - Note that unlike catchIO and tryIO, this catches all exceptions. -} +bracketIO :: (MonadMask m, MonadIO m) => IO v -> (v -> IO b) -> (v -> m a) -> m a +bracketIO setup cleanup = bracket (liftIO setup) (liftIO . cleanup) + {- Catches all exceptions except for async exceptions. - This is often better to use than catching them all, so that - ThreadKilled and UserInterrupt get through. -} catchNonAsync :: MonadCatch m => m a -> (SomeException -> m a) -> m a catchNonAsync a onerr = a `catches` - [ Handler (\ (e :: AsyncException) -> throwM e) - , Handler (\ (e :: SomeException) -> onerr e) + [ M.Handler (\ (e :: AsyncException) -> throwM e) + , M.Handler (\ (e :: SomeException) -> onerr e) ] tryNonAsync :: MonadCatch m => m a -> m (Either SomeException a) |