Minor modernization of ControlMaybe utilities.

1 files changed, 14 insertions, 12 deletions

diff --git a/Presence/ControlMaybe.hs b/Presence/ControlMaybe.hs
index 659dab74..4d9d713f 100644
--- a/Presence/ControlMaybe.hs
+++ b/Presence/ControlMaybe.hs
@@ -2,28 +2,30 @@
 module ControlMaybe where
 
 -- import GHC.IO.Exception (IOException(..))
+import Control.Monad
 import Control.Exception as Exception (IOException(..),catch)
+import System.IO.Error
 
 
+-- forM_ with less polymorphism.
 withJust :: Monad m => Maybe x -> (x -> m ()) -> m ()
-withJust (Just x) f = f x
-withJust Nothing  f = return ()
+withJust m f = forM_ m f
+{-# INLINE withJust #-}
 
 whenJust :: Monad m => m (Maybe x) -> (x -> m ()) -> m ()
-whenJust acn f = do
-    x <- acn
-    withJust x f
+whenJust acn f = acn >>= mapM_ f
+{-# INLINE whenJust #-}
 
 
 catchIO_ :: IO a -> IO a -> IO a
-catchIO_ a h = Exception.catch a (\(_ :: IOException) -> h)
-
-catchIO :: IO a -> (IOException -> IO a)  -> IO a
-catchIO body handler = Exception.catch body handler
+catchIO_ body catcher = catchIOError body (\_ -> catcher)
+{-# INLINE catchIO_ #-}
 
 handleIO_ :: IO a -> IO a -> IO a
-handleIO_ = flip catchIO_
+handleIO_ catcher body = catchIOError body (\_ -> catcher)
+{-# INLINE handleIO_ #-}
 
 
-handleIO :: (IOException -> IO a) -> IO a -> IO a
-handleIO = flip catchIO
+handleIO :: (IOError -> IO a) -> IO a -> IO a
+handleIO catcher body = catchIOError body catcher
+{-# INLINE handleIO #-}