hsfm/src/IO/Utils.hs

56 lines
1.3 KiB
Haskell

{--
HSFM, a filemanager written in Haskell.
Copyright (C) 2015 Julian Ospald
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
version 2 as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
--}
{-# OPTIONS_HADDOCK ignore-exports #-}
-- |Random and general IO utilities.
module IO.Utils where
import Control.Concurrent.STM
(
atomically
)
import Control.Concurrent.STM.TVar
(
writeTVar
, modifyTVar
, TVar
)
import Control.Monad
(
when
, unless
)
writeTVarIO :: TVar a -> a -> IO ()
writeTVarIO tvar val = atomically $ writeTVar tvar val
modifyTVarIO :: TVar a -> (a -> a) -> IO ()
modifyTVarIO tvar f = atomically $ modifyTVar tvar f
whenM :: Monad m => m Bool -> m () -> m ()
whenM mb a = mb >>= (`when` a)
unlessM :: Monad m => m Bool -> m () -> m ()
unlessM mb a = mb >>= (`unless` a)