Simplify inelegant code

src/Blog.hs

@@ -95,8 +95,8 @@ tagged collection path = do
 
 discover :: Path -> IO (Collection Article, Collection Page, Collection (Set String))
 discover path = do
-  articles <- find (Article.at) $ articlesPath path
-  pages <- maybe (return Map.empty) (find (Page.at)) $ pagesPath path
+  articles <- find Article.at $ articlesPath path
+  pages <- maybe (return Map.empty) (find Page.at) $ pagesPath path
   tags <- Map.fromList . filter (not . Set.null . snd)
     <$> (Files.find (articlesPath path </> "tags") >>= mapM (articles `tagged`))
   return (articles, pages, tags)

src/Files.hs

@@ -20,15 +20,12 @@ absoluteLink ('.':path) = path
 absoluteLink path = "/" </> path
 
 filePath :: File -> IO FilePath
-filePath file = do
-  let (thePath, test, errorMessage) =
-        case file of
-          File path -> (path, doesFileExist, (++ ": no such file"))
-          Dir path -> (path, doesDirectoryExist, (++ ": no such directory"))
-  bool <- test thePath
-  if bool
-    then return thePath
-    else die $ errorMessage thePath
+filePath (File path) = do
+  bool <- doesFileExist path
+  if bool then return path else die $ path ++ ": no such file"
+filePath (Dir path) = do
+  bool <- doesDirectoryExist path
+  if bool then return path else die $ path ++ ": no such directory"
 
 find :: FilePath -> IO [FilePath]
 find path =