Control.Prim.Monad

Documentation

type RW = RealWorld

A shorter synonym for the magical RealWorld

data RealWorld :: Type

RealWorld is deeply magical. It is primitive, but it is not unlifted (hence ptrArg). We never manipulate values of type RealWorld; it's only used in the type system, to parameterise State#.

Instances

MonadPrim RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# RealWorld -> (#State# RealWorld, a#)) -> IO a

MonadUnliftPrim RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

withRunInPrimBase :: MonadPrimBase RealWorld n => ((forall a. IO a -> n a) -> n b) -> IO b

MonadPrimBase RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

primBase :: IO a -> State# RealWorld -> (#State# RealWorld, a#)

class MonadThrow m => MonadPrim s m | m -> s where

Methods

prim :: (State# s -> (#State# s, a#)) -> m a

Construct a primitive action

Instances

MonadPrim RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# RealWorld -> (#State# RealWorld, a#)) -> IO a

MonadPrim s m => MonadPrim s (MaybeT m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> MaybeT m a

MonadPrim s (ST s)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> ST s a

MonadPrim s m => MonadPrim s (SelectT r m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> SelectT r m a

(Monoid w, MonadPrim s m) => MonadPrim s (AccumT w m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> AccumT w m a

(Monoid w, MonadPrim s m) => MonadPrim s (WriterT w m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> WriterT w m a

(Monoid w, MonadPrim s m) => MonadPrim s (WriterT w m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> WriterT w m a

MonadPrim s m => MonadPrim s (StateT st m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> StateT st m a

MonadPrim s m => MonadPrim s (StateT st m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> StateT st m a

MonadPrim s m => MonadPrim s (IdentityT m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> IdentityT m a

MonadPrim s m => MonadPrim s (ExceptT e m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> ExceptT e m a

MonadPrim s m => MonadPrim s (ReaderT r m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> ReaderT r m a

MonadPrim s m => MonadPrim s (ContT r m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> ContT r m a

(Monoid w, MonadPrim s m) => MonadPrim s (RWST r w st m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> RWST r w st m a

(Monoid w, MonadPrim s m) => MonadPrim s (RWST r w st m)

Defined in Control.Prim.Monad.Internal

Methods

prim :: (State# s -> (#State# s, a#)) -> RWST r w st m a

class MonadUnliftPrim s m => MonadPrimBase s m where

Methods

primBase :: m a -> State# s -> (#State# s, a#)

Unwrap a primitive action

Instances

MonadPrimBase RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

primBase :: IO a -> State# RealWorld -> (#State# RealWorld, a#)

MonadPrimBase s (ST s)

Defined in Control.Prim.Monad.Internal

Methods

primBase :: ST s a -> State# s -> (#State# s, a#)

MonadPrimBase s m => MonadPrimBase s (IdentityT m)

Defined in Control.Prim.Monad.Internal

Methods

primBase :: IdentityT m a -> State# s -> (#State# s, a#)

class MonadPrim s m => MonadUnliftPrim s m where

Methods

withRunInPrimBase :: MonadPrimBase s n => ((forall a. m a -> n a) -> n b) -> m b

Instances

MonadUnliftPrim RealWorld IO

Defined in Control.Prim.Monad.Internal

Methods

withRunInPrimBase :: MonadPrimBase RealWorld n => ((forall a. IO a -> n a) -> n b) -> IO b

MonadUnliftPrim s (ST s)

Defined in Control.Prim.Monad.Internal

Methods

withRunInPrimBase :: MonadPrimBase s n => ((forall a. ST s a -> n a) -> n b) -> ST s b

MonadUnliftPrim s m => MonadUnliftPrim s (IdentityT m)

Defined in Control.Prim.Monad.Internal

Methods

withRunInPrimBase :: MonadPrimBase s n => ((forall a. IdentityT m a -> n a) -> n b) -> IdentityT m b

MonadUnliftPrim s m => MonadUnliftPrim s (ReaderT r m)

Defined in Control.Prim.Monad.Internal

Methods

withRunInPrimBase :: MonadPrimBase s n => ((forall a. ReaderT r m a -> n a) -> n b) -> ReaderT r m b

prim_ :: MonadPrim s m => (State# s -> State# s) -> m ()

Construct a primitive action that does not return anything.

primBase_ :: MonadPrimBase s m => m () -> State# s -> State# s

runInPrimBase :: forall s m a b. MonadUnliftPrim s m => m a -> ((State# s -> (#State# s, a#)) -> State# s -> (#State# s, b#)) -> m b

liftPrimIO :: MonadPrim RW m => IO a -> m a

Lift an IO action to MonadPrim with the RealWorld state token. Type restricted synonym for liftPrimBase

liftPrimST :: MonadPrim s m => ST s a -> m a

Lift an ST action to MonadPrim with the same state token. Type restricted synonym for liftPrimBase

liftPrimBase :: (MonadPrimBase s n, MonadPrim s m) => n a -> m a

Lift an action from the MonadPrimBase to another MonadPrim with the same state token.

primBaseToIO :: MonadPrimBase RealWorld m => m a -> IO a

Restrict a MonadPrimBase action that works with RealWorld to IO.

primBaseToST :: MonadPrimBase s m => m a -> ST s a

Restrict a MonadPrimBase action that works in ST.

touch :: MonadPrim s m => a -> m ()

This is an action that ensures that the value is still available and garbage collector has not cleaned it up.

Make sure not to use it after some computation that doesn't return, like after forever for example, otherwise touch will simply be removed by ghc and bad things will happen. If you have a case like that, make sure to use withAlivePrimBase or withAliveUnliftPrim instead.

Since: 0.1.0

seqPrim :: MonadPrim s m => a -> m a

An action that evaluates a value to weak head normal form. Same as evaluate, except it works in a MonadPrim

Since: 0.1.0

withAlivePrimBase

Arguments

:: (MonadPrimBase s n, MonadPrim s m)

=> a

The value to preserve

-> n b

Action to run in which the value will be preserved

-> m b

Similar to touch. See withAlive# for more info.

Since: 0.1.0

withAliveUnliftPrim

Arguments

:: MonadUnliftPrim s m

=> a

The value to preserve

-> m b

Action to run in which the value will be preserved

-> m b

Similar to touch. See withAlive# for more info.

Since: 0.1.0

showsType :: Typeable t => proxy t -> ShowS

Helper function that converts a type into a string

Re-export

module Control.Monad