{-# LANGUAGE CPP #-}
#if __GLASGOW_HASKELL__ >= 702
{-# LANGUAGE Safe #-}
#endif
#if __GLASGOW_HASKELL__ >= 710
{-# LANGUAGE AutoDeriveTypeable #-}
#endif
module Control.Monad.Trans.RWS.Strict (
RWS,
rws,
runRWS,
evalRWS,
execRWS,
mapRWS,
withRWS,
RWST(..),
evalRWST,
execRWST,
mapRWST,
withRWST,
reader,
ask,
local,
asks,
writer,
tell,
listen,
listens,
pass,
censor,
state,
get,
put,
modify,
gets,
liftCallCC,
liftCallCC',
liftCatch,
) where
import Control.Monad.IO.Class
import Control.Monad.Signatures
import Control.Monad.Trans.Class
import Data.Functor.Identity
import Control.Applicative
import Control.Monad
#if MIN_VERSION_base(4,9,0)
import qualified Control.Monad.Fail as Fail
#endif
import Control.Monad.Fix
import Data.Monoid
type RWS r w s = RWST r w s Identity
rws :: (r -> s -> (a, s, w)) -> RWS r w s a
rws f = RWST (\ r s -> Identity (f r s))
{-# INLINE rws #-}
runRWS :: RWS r w s a -> r -> s -> (a, s, w)
runRWS m r s = runIdentity (runRWST m r s)
{-# INLINE runRWS #-}
evalRWS :: RWS r w s a
-> r
-> s
-> (a, w)
evalRWS m r s = let
(a, _, w) = runRWS m r s
in (a, w)
{-# INLINE evalRWS #-}
execRWS :: RWS r w s a
-> r
-> s
-> (s, w)
execRWS m r s = let
(_, s', w) = runRWS m r s
in (s', w)
{-# INLINE execRWS #-}
mapRWS :: ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b
mapRWS f = mapRWST (Identity . f . runIdentity)
{-# INLINE mapRWS #-}
withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a
withRWS = withRWST
{-# INLINE withRWS #-}
newtype RWST r w s m a = RWST { runRWST :: r -> s -> m (a, s, w) }
evalRWST :: (Monad m)
=> RWST r w s m a
-> r
-> s
-> m (a, w)
evalRWST m r s = do
(a, _, w) <- runRWST m r s
return (a, w)
{-# INLINE evalRWST #-}
execRWST :: (Monad m)
=> RWST r w s m a
-> r
-> s
-> m (s, w)
execRWST m r s = do
(_, s', w) <- runRWST m r s
return (s', w)
{-# INLINE execRWST #-}
mapRWST :: (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b
mapRWST f m = RWST $ \ r s -> f (runRWST m r s)
{-# INLINE mapRWST #-}
withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a
withRWST f m = RWST $ \ r s -> uncurry (runRWST m) (f r s)
{-# INLINE withRWST #-}
instance (Functor m) => Functor (RWST r w s m) where
fmap f m = RWST $ \ r s ->
fmap (\ (a, s', w) -> (f a, s', w)) $ runRWST m r s
{-# INLINE fmap #-}
instance (Monoid w, Functor m, Monad m) => Applicative (RWST r w s m) where
pure a = RWST $ \ _ s -> return (a, s, mempty)
{-# INLINE pure #-}
RWST mf <*> RWST mx = RWST $ \ r s -> do
(f, s', w) <- mf r s
(x, s'',w') <- mx r s'
return (f x, s'', w `mappend` w')
{-# INLINE (<*>) #-}
instance (Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m) where
empty = RWST $ \ _ _ -> mzero
{-# INLINE empty #-}
RWST m <|> RWST n = RWST $ \ r s -> m r s `mplus` n r s
{-# INLINE (<|>) #-}
instance (Monoid w, Monad m) => Monad (RWST r w s m) where
#if !(MIN_VERSION_base(4,8,0))
return a = RWST $ \ _ s -> return (a, s, mempty)
{-# INLINE return #-}
#endif
m >>= k = RWST $ \ r s -> do
(a, s', w) <- runRWST m r s
(b, s'',w') <- runRWST (k a) r s'
return (b, s'', w `mappend` w')
{-# INLINE (>>=) #-}
fail msg = RWST $ \ _ _ -> fail msg
{-# INLINE fail #-}
#if MIN_VERSION_base(4,9,0)
instance (Monoid w, Fail.MonadFail m) => Fail.MonadFail (RWST r w s m) where
fail msg = RWST $ \ _ _ -> Fail.fail msg
{-# INLINE fail #-}
#endif
instance (Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) where
mzero = RWST $ \ _ _ -> mzero
{-# INLINE mzero #-}
RWST m `mplus` RWST n = RWST $ \ r s -> m r s `mplus` n r s
{-# INLINE mplus #-}
instance (Monoid w, MonadFix m) => MonadFix (RWST r w s m) where
mfix f = RWST $ \ r s -> mfix $ \ ~(a, _, _) -> runRWST (f a) r s
{-# INLINE mfix #-}
instance (Monoid w) => MonadTrans (RWST r w s) where
lift m = RWST $ \ _ s -> do
a <- m
return (a, s, mempty)
{-# INLINE lift #-}
instance (Monoid w, MonadIO m) => MonadIO (RWST r w s m) where
liftIO = lift . liftIO
{-# INLINE liftIO #-}
reader :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
reader = asks
{-# INLINE reader #-}
ask :: (Monoid w, Monad m) => RWST r w s m r
ask = RWST $ \ r s -> return (r, s, mempty)
{-# INLINE ask #-}
local :: (r -> r) -> RWST r w s m a -> RWST r w s m a
local f m = RWST $ \ r s -> runRWST m (f r) s
{-# INLINE local #-}
asks :: (Monoid w, Monad m) => (r -> a) -> RWST r w s m a
asks f = RWST $ \ r s -> return (f r, s, mempty)
{-# INLINE asks #-}
writer :: (Monad m) => (a, w) -> RWST r w s m a
writer (a, w) = RWST $ \ _ s -> return (a, s, w)
{-# INLINE writer #-}
tell :: (Monad m) => w -> RWST r w s m ()
tell w = RWST $ \ _ s -> return ((),s,w)
{-# INLINE tell #-}
listen :: (Monad m) => RWST r w s m a -> RWST r w s m (a, w)
listen m = RWST $ \ r s -> do
(a, s', w) <- runRWST m r s
return ((a, w), s', w)
{-# INLINE listen #-}
listens :: (Monad m) => (w -> b) -> RWST r w s m a -> RWST r w s m (a, b)
listens f m = RWST $ \ r s -> do
(a, s', w) <- runRWST m r s
return ((a, f w), s', w)
{-# INLINE listens #-}
pass :: (Monad m) => RWST r w s m (a, w -> w) -> RWST r w s m a
pass m = RWST $ \ r s -> do
((a, f), s', w) <- runRWST m r s
return (a, s', f w)
{-# INLINE pass #-}
censor :: (Monad m) => (w -> w) -> RWST r w s m a -> RWST r w s m a
censor f m = RWST $ \ r s -> do
(a, s', w) <- runRWST m r s
return (a, s', f w)
{-# INLINE censor #-}
state :: (Monoid w, Monad m) => (s -> (a,s)) -> RWST r w s m a
state f = RWST $ \ _ s -> case f s of (a,s') -> return (a, s', mempty)
{-# INLINE state #-}
get :: (Monoid w, Monad m) => RWST r w s m s
get = RWST $ \ _ s -> return (s, s, mempty)
{-# INLINE get #-}
put :: (Monoid w, Monad m) => s -> RWST r w s m ()
put s = RWST $ \ _ _ -> return ((), s, mempty)
{-# INLINE put #-}
modify :: (Monoid w, Monad m) => (s -> s) -> RWST r w s m ()
modify f = RWST $ \ _ s -> return ((), f s, mempty)
{-# INLINE modify #-}
gets :: (Monoid w, Monad m) => (s -> a) -> RWST r w s m a
gets f = RWST $ \ _ s -> return (f s, s, mempty)
{-# INLINE gets #-}
liftCallCC :: (Monoid w) =>
CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
liftCallCC callCC f = RWST $ \ r s ->
callCC $ \ c ->
runRWST (f (\ a -> RWST $ \ _ _ -> c (a, s, mempty))) r s
{-# INLINE liftCallCC #-}
liftCallCC' :: (Monoid w) =>
CallCC m (a,s,w) (b,s,w) -> CallCC (RWST r w s m) a b
liftCallCC' callCC f = RWST $ \ r s ->
callCC $ \ c ->
runRWST (f (\ a -> RWST $ \ _ s' -> c (a, s', mempty))) r s
{-# INLINE liftCallCC' #-}
liftCatch :: Catch e m (a,s,w) -> Catch e (RWST r w s m) a
liftCatch catchE m h =
RWST $ \ r s -> runRWST m r s `catchE` \ e -> runRWST (h e) r s
{-# INLINE liftCatch #-}