Removing CmdArgs

main.hs

@@ -1,58 +1,39 @@
-{-# LANGUAGE DeriveDataTypeable, RecordWildCards #-}
+{-# LANGUAGE RecordWildCards #-}
 
 import System.IO
-import System.Console.CmdArgs
 import Control.Monad (when)
 
 import Paths_alea (getDataFileName)
 import Alea.Diceware
 import Alea.Random
 
-_NAME = "Alea"
-_VERSION = "0.3.0"
-_INFO = _NAME ++ " version " ++ _VERSION
-_ABOUT = "a diceware passphrase generator"
-_COPYRIGHT = "(C) Michele Guerini Rocco 2014"
-
-data Args = Args
+data ProgArgs = ProgArgs
 	{ interactive  :: Bool
 	, dictionary   :: FilePath
 	, phraseLength :: Int
 	, phrases      :: Int
-	} deriving (Data, Typeable, Show, Eq)
+	} deriving (Show)
 
-progArgs :: Args
-progArgs = Args
-	{ interactive  = def &= help "Manually insert numbers"
-	, dictionary   = def &= help "Specify dictionary file path"
-	, phraseLength = def &= help "Number of words in a passphrase"
-	, phrases      = def &= help "Number of passphrases to generate"
-	}
-
-getProgArgs :: IO Args
-getProgArgs = cmdArgs $ progArgs
-    &= versionArg [explicit, name "version", name "v", summary _INFO]
-    &= summary (_INFO ++ ", " ++ _COPYRIGHT)
-    &= help _ABOUT
-    &= helpArg [explicit, name "help", name "h"]
-    &= program _NAME
+parser :: IO (ParserSpec ProgArgs)
+parser = path >>= \path -> return $ ProgArgs
+  `parsedBy` boolFlag      "interactive" `Descr` "Manually insert numbers"
+  `andBy`    optFlag  path "dictionary"  `Descr` "Specify dictionary file path"
+  `andBy`    optFlag  6    "lenght"      `Descr` "Number of words in a passphrase"
+  `andBy`    optFlag  1    "phrases"     `Descr` "Number of passphrases to generate"
 
+interface :: IO (CmdLnInterface ProgArgs)
+interface = 
+  (`setAppDescr` "A diceware passphrase generator") <$>
+  (`setAppEpilog` "Alea iacta est.") <$>
+  (mkApp =<< parser)
 
 main :: IO ()
 main = getProgArgs >>= defaults >>= exec
 
--- Assign default values to unspecified args
-defaults :: Args -> IO Args
-defaults args@Args{..} = do
-	dictionary' <- if null dictionary
-					then getDataFileName "dict/diceware" >>= readFile
-					else readFile dictionary
-	let phraseLength' = if phraseLength == 0 then 6 else phraseLength
-	return args { dictionary = dictionary', phraseLength = phraseLength'}
 
 -- Main function
-exec :: Args -> IO ()
-exec args@Args{..} =
+exec :: ProgArgs -> IO ()
+exec args@ProgArgs{..} =
 	if interactive
 		then interact (unlines . map dice . lines)
 		else do