Hi, I ran your code thought HLint (http://community.haskell.org/~ndm/hlint), and it suggested a couple of things (mainly eta reduce). The most interesting suggestions are on your main function:
main :: IO () main = do done <- isEOF case done of True -> return () False -> do prob <- getLine test prob main
It suggests: Example.lhs:432:3: Warning: Use if Found: case done of True -> return () False -> do prob <- getLine test prob main Why not: if done then return () else do prob <- getLine test prob main Changing that and rerunning says: Example.lhs:432:3: Error: Use unless Found: if done then return () else do prob <- getLine test prob main Why not: unless done $ do prob <- getLine test prob main So I (or rather HLint) recommends you do:
main :: IO () main = do done <- isEOF unless done $ do prob <- getLine test prob main
Thanks, Neil