module Control.Monad.Reader.Extras
( MonadReader1(..)
) where
#if __GLASGOW_HASKELL__ < 710
import Data.Monoid
#endif
import Control.Monad.Trans.Class
import Control.Monad.Reader
import qualified Control.Monad.Trans.Cont as C
import qualified Control.Monad.Trans.Except as E
import qualified Control.Monad.Trans.Identity as I
import qualified Control.Monad.Trans.List as L
import qualified Control.Monad.Trans.Maybe as M
import qualified Control.Monad.Trans.Reader as R
import qualified Control.Monad.Trans.RWS.Lazy as RWS.Lazy
import qualified Control.Monad.Trans.RWS.Strict as RWS.Strict
import qualified Control.Monad.Trans.State.Lazy as S.Lazy
import qualified Control.Monad.Trans.State.Strict as S.Strict
import qualified Control.Monad.Trans.Writer.Lazy as W.Lazy
import qualified Control.Monad.Trans.Writer.Strict as W.Strict
class MonadTrans t => MonadReader1 t where
local1 :: MonadReader r m => (r -> r) -> t m a -> t m a
instance MonadReader1 (C.ContT r) where
local1 f = C.liftLocal ask local f
instance MonadReader1 (E.ExceptT e) where
local1 f = E.mapExceptT (local f)
instance MonadReader1 I.IdentityT where
local1 f = I.mapIdentityT (local f)
instance MonadReader1 L.ListT where
local1 f = L.mapListT (local f)
instance MonadReader1 M.MaybeT where
local1 f = M.mapMaybeT (local f)
instance MonadReader1 (R.ReaderT r) where
local1 f = R.mapReaderT (local f)
instance Monoid w => MonadReader1 (RWS.Lazy.RWST r w s) where
local1 f = RWS.Lazy.mapRWST (local f)
instance Monoid w => MonadReader1 (RWS.Strict.RWST r w s) where
local1 f = RWS.Strict.mapRWST (local f)
instance MonadReader1 (S.Lazy.StateT s) where
local1 f = S.Lazy.mapStateT (local f)
instance MonadReader1 (S.Strict.StateT s) where
local1 f = S.Strict.mapStateT (local f)
instance Monoid w => MonadReader1 (W.Lazy.WriterT w) where
local1 f = W.Lazy.mapWriterT (local f)
instance Monoid w => MonadReader1 (W.Strict.WriterT w) where
local1 f = W.Strict.mapWriterT (local f)