{-# LANGUAGE TypeOperators #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE PolyKinds #-} ----------------------------------------------------------------------------- -- | -- Module : Type.Family.Monoid -- Copyright : Copyright (C) 2015 Kyle Carter -- License : BSD3 -- -- Maintainer : Kyle Carter -- Stability : experimental -- Portability : RankNTypes -- -- Type-level @Monoid@, defined as an open type family. -- ----------------------------------------------------------------------------- module Type.Family.Monoid where type family Mempty :: k type family (a :: k) <> (b :: k) :: k