ghc-mod/Utils.hs
2015-03-28 02:32:44 +01:00

36 lines
848 B
Haskell

{-# LANGUAGE CPP #-}
module Utils where
import Control.Applicative
import Data.Traversable
import System.Directory
#if MIN_VERSION_directory(1,2,0)
import Data.Time (UTCTime)
#else
import System.Time (ClockTime)
#endif
#if MIN_VERSION_directory(1,2,0)
type ModTime = UTCTime
#else
type ModTime = ClockTime
#endif
data TimedFile = TimedFile { tfPath :: FilePath, tfTime :: ModTime }
deriving (Eq, Show)
instance Ord TimedFile where
compare (TimedFile _ a) (TimedFile _ b) = compare a b
timeFile :: FilePath -> IO TimedFile
timeFile f = TimedFile <$> pure f <*> getModificationTime f
mightExist :: FilePath -> IO (Maybe FilePath)
mightExist f = do
exists <- doesFileExist f
return $ if exists then (Just f) else (Nothing)
timeMaybe :: FilePath -> IO (Maybe TimedFile)
timeMaybe f = traverse timeFile =<< mightExist f