ColorTypeEnum.hs

-- ColorTypeEnum.hs
-- http://www.haskell.org/haskellwiki/Performance/Data_types#Enumerations
{-# LANGUAGE GeneralizedNewtypeDeriving #-}

newtype Color = Color Int deriving (Eq,Ord,Enum)
(red:green:blue:_) = [Color 1 ..]

colorInt (Color int) = int

main = putStrLn ("List: " ++ show (map colorInt [red,green,blue,green,red]))