The mistake might be on my side, since I expected the following to work
(but it doesn't, most likely for good reason, I didn't read any
TypeFamilies papers yet):
{-# LANGUAGE GeneralizedNewtypeDeriving, TypeFamilies #-}
module Main where
import Control.Monad.State
data S = S T
data T = T
type
All,
The following code results in a compilation error (I tried GHC 7.4.1 & a
7.7.20130430 build):
{-# LANGUAGE TypeFamilies,
GeneralizedNewtypeDeriving,
StandaloneDeriving #-}
module Main where
import Control.Applicative
import Control.Monad.RWS
data C = C
data E = E
