never executed always true always false

    1 module HelVM.HelMA.Automata.Piet.Types.Hue (
    2   hueChange,
    3   Hue(..),
    4 ) where
    5 
    6 import           HelVM.HelMA.Automata.Piet.Types.Extra
    7 
    8 hueChange :: Hue -> Hue -> Hue
    9 hueChange = changeDiff 6
   10 
   11 data Hue = Red | Yellow | Green | Cyan | Blue | Magenta
   12   deriving stock (Bounded , Show , Read, Eq , Ord , Enum)