Bits of optimisation

app/Main.hs

@@ -10,4 +10,4 @@ main = do
     createExample testfile
     sheet <- parseSheet testfile
     putStrLn $ "wrote example character named \"" ++ getName sheet ++ "\" to: " ++ testfile
-    listSkills sheet
+    listSkillNames sheet

flake.nix

@@ -20,7 +20,6 @@
         jailbreakUnbreak = pkg:
           pkgs.haskell.lib.doJailbreak (pkg.overrideAttrs (_: { meta = { }; }));
 
-        # DON'T FORGET TO PUT YOUR PACKAGE NAME HERE, REMOVING `throw`
         packageName = "sheet-parser-hs";
       in {
         packages.${packageName} =

lib/DND/Sheet/Parser.hs

@@ -1,35 +1,36 @@
 module DND.Sheet.Parser
-(getSheet
-, parseSheet
+( parseSheet
+--, getSheet
 , listSkills
 , createExample
 , getName
+, listSkillNames
 ) where
 
 import Data.Aeson
 import DND.Sheet.Content
 import DND.Bob(bob)
+import Control.Monad
 import qualified Data.ByteString.Lazy as B
 import qualified Data.ByteString.Lazy.UTF8 as BSU
 import Data.Maybe (fromJust)
 
-getSheet :: FilePath -> IO B.ByteString
-getSheet = B.readFile
+--getSheet :: FilePath -> IO B.ByteString
+--getSheet = B.readFile
 
 parseSheet :: FilePath -> IO Character
-parseSheet x = do
-    file <- B.readFile x
-    let character = decode file :: Maybe Character
-    return $ fromJust character
+parseSheet x = unwrap . decode =<< B.readFile x
+    where unwrap (Just y) = return y
+          unwrap Nothing  = error $ "Failed to parse character sheet: " ++ x
 
-listSkills :: Character -> IO ()
-listSkills = mapM_ (mapM_ putStrLn)
-           . filter (not . null)
-           . map (map skillName . skills)
-           . stats
+listSkills :: Character -> [Skill]
+listSkills = join . map skills . stats
+
+listSkillNames :: Character -> IO ()
+listSkillNames = mapM_ (putStrLn . skillName) . listSkills
 
 createExample :: FilePath -> IO ()
 createExample = flip encodeFile bob
 
 getName :: Character -> String
-getName = charName . preamble
+getName = charName . preamble