test.hs

{-# LANGUAGE DeriveFunctor #-}
{-# LANGUAGE TypeSynonymInstances #-}

import Data.Functor.Foldable

newtype Object a = Object {getObject :: a} deriving (Show, Eq, Functor)
data Label l a = Label { label :: l, inner :: a } deriving (Show, Eq, Functor)
data FooF l a = FooF { nested :: (Label l) (Object a) }

type LabelFunctor l = Fix (FooF l)

instance Functor LabelFunctor where
  fmap = undefined

main = print ()