module Bob (responseFor) where
import Data.Char

responseForNothing = "Fine. Be that way!"
responseForYelledQuestion = "Calm down, I know what I'm doing!"
responseForShout = "Whoa, chill out!"
responseForQuestion = "Sure."
responseForAnythingElse = "Whatever."

isQuestion xs = last xs == '?'

responseForShouting :: String -> String
responseForShouting xs
  | isQuestion xs = responseForYelledQuestion
  | otherwise = responseForShout

responseFor :: String -> String
responseFor xs
  | (null . filter isAlphaNum) xs = responseForNothing
  | (all isUpper && null) (filter isAlpha xs) = responseForShouting xs
  | isQuestion xs = responseForQuestion
  | otherwise = responseForAnythingElse