1 files changed, 17 insertions(+), 9 deletions(-)

M exec/Main.hs

@@ 1,23 1,31 @@
 module Main (main) where
 
-import           CLI                (Opts (..), parse)
-import qualified Data.Map           as M
-import qualified Data.Text          as T
+import           CLI         (Opts (..), parse)
+import qualified Data.Map    as M
+import qualified Data.Text   as T
 import           Prelude
-import           Unerf              (checkAll, defaultPath)
-import           Unerf.Tool         (Scripts, Tool)
+import           Unerf       (checkAll, defaultPath)
+import           Unerf.Tool  (Scripts, Tool)
+
+-- | Isomorphic to `Maybe` but with distinct meaning.
+data Result a
+  = Output a
+  | NoOutput
 
 main :: IO ()
-main = putTextLn =<< fmap (outputTools . M.toList) . checkAll =<< getPath
+main = exit =<< fmap toOutput . checkAll =<< getPath
   where getPath = sanitisePath . fromMaybe defaultPath . path <$> parse
+        toOutput = outputTools . M.toList
+        exit NoOutput   = exitFailure
+        exit (Output x) = putTextLn x
 
 -- | Fixes inputs without a trailing slash, doesn't break those with one.
 sanitisePath :: Text -> Text
 sanitisePath = (<> "/")
 
-outputTools :: [(Tool, Scripts)] -> Text
-outputTools [] = "Nothing found."
-outputTools xs = T.intercalate "\n" $ uncurry outputTool <$> xs
+outputTools :: [(Tool, Scripts)] -> Result Text
+outputTools [] = NoOutput
+outputTools xs = Output . T.intercalate "\n" $ uncurry outputTool <$> xs
 
 outputTool :: Tool -> Scripts -> Text
 outputTool x ys = show x <> foldMap (outputScripts . toList) ys