module Data.Monoid.Monad.Reader
( module Control.Monad.Reader
, module Data.Monoid.Reducer
) where
import Control.Monad.Reader
import Data.Monoid.Reducer
instance Monoid m => Monoid (Reader e m) where
mempty = return mempty
mappend = liftM2 mappend
instance Monoid m => Reducer m (Reader e m) where
unit = return
instance (Monad m, Monoid n) => Monoid (ReaderT e m n) where
mempty = return mempty
mappend = liftM2 mappend
instance (Monad m, Monoid n) => Reducer n (ReaderT e m n) where
unit = return
instance (Monad m, Monoid n) => Reducer (m n) (ReaderT e m n) where
unit = lift