module Distribution.Cab.GenPaths (genPaths) where
import Control.Applicative
import Control.Exception
import Control.Monad
import Data.List (isSuffixOf)
import Distribution.Cab.Utils (readGenericPackageDescription, unPackageName)
import Distribution.Package (pkgName, pkgVersion)
import Distribution.PackageDescription
import Distribution.Verbosity (silent)
import Distribution.Version
import System.Directory
genPaths :: IO ()
genPaths = do
(nm,ver) <- getCabalFile >>= getNameVersion
let file = "Paths_" ++ nm ++ ".hs"
check file >> do
putStrLn $ "Writing " ++ file ++ "..."
writeFile file $ "module Paths_" ++ nm ++ " where\n"
++ "import Data.Version\n"
++ "\n"
++ "version :: Version\n"
++ "version = " ++ show ver ++ "\n"
where
check file = do
exist <- doesFileExist file
when exist . throwIO . userError $ file ++ " already exists"
getNameVersion :: FilePath -> IO (String,Version)
getNameVersion file = do
desc <- readGenericPackageDescription silent file
let pkg = package . packageDescription $ desc
nm = unPackageName $ pkgName pkg
name = map (trans '-' '_') nm
version = pkgVersion pkg
return (name, version)
where
trans c1 c2 c
| c == c1 = c2
| otherwise = c
getCabalFile :: IO FilePath
getCabalFile = do
cnts <- (filter isCabal <$> getDirectoryContents ".")
>>= filterM doesFileExist
case cnts of
[] -> throwIO $ userError "Cabal file does not exist"
cfile:_ -> return cfile
where
isCabal :: String -> Bool
isCabal nm = ".cabal" `isSuffixOf` nm && length nm > 6