{-# LANGUAGE Unsafe #-}
{-# LANGUAGE NoImplicitPrelude, MagicHash, UnboxedTuples, RankNTypes #-}
{-# OPTIONS_HADDOCK not-home #-}
module GHC.ST (
ST(..), STret(..), STRep,
runST,
liftST, unsafeInterleaveST, unsafeDupableInterleaveST
) where
import GHC.Base
import GHC.Show
default ()
newtype ST s a = ST (STRep s a)
type STRep s a = State# s -> (# State# s, a #)
instance Functor (ST s) where
fmap :: forall a b. (a -> b) -> ST s a -> ST s b
fmap a -> b
f (ST STRep s a
m) = STRep s b -> ST s b
forall s a. STRep s a -> ST s a
ST (STRep s b -> ST s b) -> STRep s b -> ST s b
forall a b. (a -> b) -> a -> b
$ \ State# s
s ->
case (STRep s a
m State# s
s) of { (# State# s
new_s, a
r #) ->
(# State# s
new_s, a -> b
f a
r #) }
instance Applicative (ST s) where
{-# INLINE pure #-}
{-# INLINE (*>) #-}
pure :: forall a. a -> ST s a
pure a
x = STRep s a -> ST s a
forall s a. STRep s a -> ST s a
ST (\ State# s
s -> (# State# s
s, a
x #))
ST s a
m *> :: forall a b. ST s a -> ST s b -> ST s b
*> ST s b
k = ST s a
m ST s a -> (a -> ST s b) -> ST s b
forall a b. ST s a -> (a -> ST s b) -> ST s b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \ a
_ -> ST s b
k
<*> :: forall a b. ST s (a -> b) -> ST s a -> ST s b
(<*>) = ST s (a -> b) -> ST s a -> ST s b
forall (m :: * -> *) a b. Monad m => m (a -> b) -> m a -> m b
ap
liftA2 :: forall a b c. (a -> b -> c) -> ST s a -> ST s b -> ST s c
liftA2 = (a -> b -> c) -> ST s a -> ST s b -> ST s c
forall (m :: * -> *) a1 a2 r.
Monad m =>
(a1 -> a2 -> r) -> m a1 -> m a2 -> m r
liftM2
instance Monad (ST s) where
{-# INLINE (>>=) #-}
>> :: forall a b. ST s a -> ST s b -> ST s b
(>>) = ST s a -> ST s b -> ST s b
forall a b. ST s a -> ST s b -> ST s b
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
(*>)
(ST STRep s a
m) >>= :: forall a b. ST s a -> (a -> ST s b) -> ST s b
>>= a -> ST s b
k
= STRep s b -> ST s b
forall s a. STRep s a -> ST s a
ST (\ State# s
s ->
case (STRep s a
m State# s
s) of { (# State# s
new_s, a
r #) ->
case (a -> ST s b
k a
r) of { ST STRep s b
k2 ->
(STRep s b
k2 State# s
new_s) }})
instance Semigroup a => Semigroup (ST s a) where
<> :: ST s a -> ST s a -> ST s a
(<>) = (a -> a -> a) -> ST s a -> ST s a -> ST s a
forall a b c. (a -> b -> c) -> ST s a -> ST s b -> ST s c
forall (f :: * -> *) a b c.
Applicative f =>
(a -> b -> c) -> f a -> f b -> f c
liftA2 a -> a -> a
forall a. Semigroup a => a -> a -> a
(<>)
instance Monoid a => Monoid (ST s a) where
mempty :: ST s a
mempty = a -> ST s a
forall a. a -> ST s a
forall (f :: * -> *) a. Applicative f => a -> f a
pure a
forall a. Monoid a => a
mempty
data STret s a = STret (State# s) a
liftST :: ST s a -> State# s -> STret s a
liftST :: forall s a. ST s a -> State# s -> STret s a
liftST (ST STRep s a
m) = \State# s
s -> case STRep s a
m State# s
s of (# State# s
s', a
r #) -> State# s -> a -> STret s a
forall s a. State# s -> a -> STret s a
STret State# s
s' a
r
noDuplicateST :: ST s ()
noDuplicateST :: forall s. ST s ()
noDuplicateST = STRep s () -> ST s ()
forall s a. STRep s a -> ST s a
ST (STRep s () -> ST s ()) -> STRep s () -> ST s ()
forall a b. (a -> b) -> a -> b
$ \State# s
s -> (# State# s -> State# s
forall d. State# d -> State# d
noDuplicate# State# s
s, () #)
{-# INLINE unsafeInterleaveST #-}
unsafeInterleaveST :: ST s a -> ST s a
unsafeInterleaveST :: forall s a. ST s a -> ST s a
unsafeInterleaveST ST s a
m = ST s a -> ST s a
forall s a. ST s a -> ST s a
unsafeDupableInterleaveST (ST s ()
forall s. ST s ()
noDuplicateST ST s () -> ST s a -> ST s a
forall a b. ST s a -> ST s b -> ST s b
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> ST s a
m)
{-# NOINLINE unsafeDupableInterleaveST #-}
unsafeDupableInterleaveST :: ST s a -> ST s a
unsafeDupableInterleaveST :: forall s a. ST s a -> ST s a
unsafeDupableInterleaveST (ST STRep s a
m) = STRep s a -> ST s a
forall s a. STRep s a -> ST s a
ST ( \ State# s
s ->
let
r :: a
r = case STRep s a
m State# s
s of (# State# s
_, a
res #) -> a
res
in
(# State# s
s, a
r #)
)
instance Show (ST s a) where
showsPrec :: Int -> ST s a -> ShowS
showsPrec Int
_ ST s a
_ = String -> ShowS
showString String
"<<ST action>>"
showList :: [ST s a] -> ShowS
showList = (ST s a -> ShowS) -> [ST s a] -> ShowS
forall a. (a -> ShowS) -> [a] -> ShowS
showList__ (Int -> ST s a -> ShowS
forall a. Show a => Int -> a -> ShowS
showsPrec Int
0)
{-# INLINE runST #-}
runST :: (forall s. ST s a) -> a
runST :: forall a. (forall s. ST s a) -> a
runST (ST STRep RealWorld a
st_rep) = case STRep RealWorld a -> (# State# RealWorld, a #)
forall o. (State# RealWorld -> o) -> o
runRW# STRep RealWorld a
st_rep of (# State# RealWorld
_, a
a #) -> a
a