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|
{-# LANGUAGE MagicHash, UnboxedTuples, Rank2Types, FlexibleInstances,
MultiParamTypeClasses, UndecidableInstances, RecursiveDo #-}
{- |
Module : Control.Monad.ST.Trans
Copyright : Josef Svenningsson 2008-2010
(c) The University of Glasgow, 1994-2000
License : BSD
Maintainer : josef.svenningsson@gmail.com, Andreas Abel
Stability : stable
Portability : non-portable (GHC Extensions)
This module provides the implementation of the 'STT' type for those
occasions where it is needed in order to implement new liftings through
operations in other monads.
Warning! This monad transformer should not be used with monads that
can contain multiple answers, like the list monad. The reason is that
the will be duplicated across the different answers and this cause
Bad Things to happen (such as loss of referential transparency). Safe
monads include the monads State, Reader, Writer, Maybe and
combinations of their corresponding monad transformers.
-}
module Control.Monad.ST.Trans.Internal where
import GHC.Base
import GHC.ST hiding (liftST)
import qualified Control.Monad.Fail as MF
import Control.Monad.Fix
import Control.Monad.Trans
import Control.Monad.Error.Class
import Control.Monad.Reader.Class
import Control.Monad.State.Class
import Control.Monad.Writer.Class
#if __GLASGOW_HASKELL__ <= 708
import Control.Applicative
#endif
import Data.Array.ST
import Data.Array.Base
import GHC.Int (Int8, Int16, Int32, Int64)
import GHC.Word (Word8, Word16, Word32, Word64)
import GHC.Ptr (Ptr, FunPtr)
import GHC.Stable (StablePtr)
-- | 'STT' is the monad transformer providing polymorphic updateable references
newtype STT s m a = STT (State# s -> m (STTRet s a))
unSTT :: STT s m a -> (State# s -> m (STTRet s a))
unSTT (STT f) = f
-- | 'STTRet' is needed to encapsulate the unboxed state token that GHC passes
-- around. This type is essentially a pair, but an ordinary pair is not
-- not allowed to contain unboxed types.
data STTRet s a = STTRet (State# s) a
-- | Lifting the `ST` monad into `STT`. The library uses this function
-- extensively to be able to reuse functions from `ST`.
liftST :: Applicative m => ST s a -> STT s m a
liftST (ST f) = STT (\s -> let !(# s', a #) = f s in pure (STTRet s' a))
{-# INLINE liftST #-}
-- All instances have to go in this module because otherwise they
-- would be orphan instances.
instance (Monad m, Functor m) => Monad (STT s m) where
return = pure
STT m >>= k = STT $ \st ->
do ret <- m st
case ret of
STTRet new_st a ->
unSTT (k a) new_st
instance (MF.MonadFail m, Functor m) => MF.MonadFail (STT s m) where
fail msg = lift (fail msg)
instance (MonadIO m, Functor m) => MonadIO (STT s m) where
liftIO = lift . liftIO
instance MonadTrans (STT s) where
lift m = STT $ \st ->
do a <- m
return (STTRet st a)
liftSTT :: STT s m a -> State# s -> m (STTRet s a)
liftSTT (STT m) s = m s
instance (MonadFix m, Functor m) => MonadFix (STT s m) where
mfix k = STT $ \ s -> mdo
ans@(STTRet _ r) <- liftSTT (k r) s
return ans
instance Functor (STTRet s) where
fmap f (STTRet s a) = STTRet s (f a)
instance Functor m => Functor (STT s m) where
fmap f (STT g) = STT $ \s# -> (fmap . fmap) f (g s#)
instance (Monad m, Functor m) => Applicative (STT s m) where
pure a = STT $ \s# -> return (STTRet s# a)
(STT m) <*> (STT n) = STT $ \s1 ->
do (STTRet s2 f) <- m s1
(STTRet s3 x) <- n s2
return (STTRet s3 (f x))
instance (Monad m, Alternative m) => Alternative (STT s m) where
empty = STT $ \_ -> empty
STT m <|> STT n = STT $ \s# -> m s# <|> n s#
-- Instances of other monad classes
instance (MonadError e m, Functor m) => MonadError e (STT s m) where
throwError e = lift (throwError e)
catchError (STT m) f = STT $ \st -> catchError (m st)
(\e -> unSTT (f e) st)
instance (MonadReader r m, Functor m) => MonadReader r (STT s m) where
ask = lift ask
local f (STT m) = STT $ \st -> local f (m st)
instance (MonadState s m, Functor m) => MonadState s (STT s1 m) where
get = lift get
put s = lift (put s)
instance (MonadWriter w m, Functor m) => MonadWriter w (STT s m) where
tell w = lift (tell w)
listen (STT m)= STT $ \st1 -> do (STTRet st2 a, w) <- listen (m st1)
return (STTRet st2 (a,w))
pass (STT m) = STT $ \st1 -> pass (do (STTRet st2 (a,f)) <- m st1
return (STTRet st2 a, f))
-- MArray instances
instance (Applicative m, Monad m) => MArray (STArray s) e (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Bool (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Char (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Int (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Word (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) (Ptr a) (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) (FunPtr a) (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Float (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Double (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) (StablePtr a) (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Int8 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Int16 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Int32 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Int64 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Word8 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Word16 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Word32 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
instance (Applicative m, Monad m) => MArray (STUArray s) Word64 (STT s m) where
{-# INLINE getBounds #-}
getBounds arr = liftST (getBounds arr)
{-# INLINE getNumElements #-}
getNumElements arr = liftST (getNumElements arr)
{-# INLINE newArray #-}
newArray bnds e = liftST (newArray bnds e)
{-# INLINE newArray_ #-}
newArray_ arrBounds = liftST (newArray_ arrBounds)
{-# INLINE unsafeNewArray_ #-}
unsafeNewArray_ bnds = liftST (unsafeNewArray_ bnds)
{-# INLINE unsafeRead #-}
unsafeRead arr i = liftST (unsafeRead arr i)
{-# INLINE unsafeWrite #-}
unsafeWrite arr i e = liftST (unsafeWrite arr i e)
|
