git-annex/Utility/Misc.hs
2011-11-07 21:27:43 -04:00

30 lines
842 B
Haskell

{- misc utility functions
-
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.Misc where
import System.IO
import Control.Monad
{- A version of hgetContents that is not lazy. Ensures file is
- all read before it gets closed. -}
hGetContentsStrict :: Handle -> IO String
hGetContentsStrict = hGetContents >=> \s -> length s `seq` return s
{- A version of readFile that is not lazy. -}
readFileStrict :: FilePath -> IO String
readFileStrict = readFile >=> \s -> length s `seq` return s
{- Attempts to read a value from a String. -}
readMaybe :: (Read a) => String -> Maybe a
readMaybe s = case reads s of
((x,_):_) -> Just x
_ -> Nothing
{- Catches IO errors and returns a Bool -}
catchBool :: IO Bool -> IO Bool
catchBool = flip catch (const $ return False)