Deriving Generic1

Ryan If you compile newtype Compose f g a = Compose (f (g a)) deriving( Generic1 ) and do –show-iface on the resulting hi file, you’ll see $fGeneric1Compose :: forall (f :: * -> *) k (g :: k -> *). Functor f => Generic1 (Compose f g) I was expecting to see $fGeneric1Compose :: forall (f :: k1 -> *) k (g :: k -> k1). (..something..) => Generic1 (Compose f g) Otherwise the Generic1 instance only works if its first argument has kind (* -> *). Is that the intention? Maybe so… Simon