-
-readArgs :: [String] -> Either String Args
-readArgs plop = undefined
-{--readArgs (name:value:rest) = case name of
- "-x" -> { xml = value }
- "-d" -> { moviesDir = value }--}
+usage = "Usage : %s -x <XML file> [-d <Movies dir>]\n"
+
+checkArgs :: Maybe Args -> Maybe Args
+checkArgs Nothing = Nothing
+checkArgs (Just args) = if any (\(a, _) -> a == XML) args
+ then Just args
+ else Nothing
+
+readArgs :: [String] -> Maybe Args
+readArgs (name:value:rest)
+ | name == "-x" = (XML, value) <:> readArgs rest
+ | name == "-d" = (MoviesDir, value) <:> readArgs rest
+ | otherwise = Nothing
+ where
+ _ <:> Nothing = Nothing
+ arg <:> Just args = Just $ arg : args
+readArgs (_:[]) = Nothing
+readArgs (_) = Just []