Haskell case pattern matching example

cases.hs

data Colour = Red | Green | Blue | Yellow
data Shape = Skinny | Round | Triangular
data Fruit = Apple | Banana | Strawberry

data Appearance = Appearance { colour :: Colour, shape :: Shape }

defruitify :: Fruit -> Appearance
defruitify fruit = case fruit of
  Apple -> Appearance { colour = Red, shape = Round }
  Banana -> Appearance { colour = Yellow, shape = Skinny }
  Strawberry -> Appearance { colour = Red, shape = Triangular }

fruitify :: Appearance -> Maybe Fruit
fruitify appearance = case appearance of
  Appearance { colour = Red, shape = Round } -> Just Apple
  Appearance { colour = Red, shape = Triangular } -> Just Strawberry
  Appearance { colour = Yellow, shape = _ } -> Just Banana -- Anything yellow is a banana, right?
  _ -> Nothing

Far from idiomatic but a simple contrived example nevertheless.