primitive-0.3.1: Wrappers for primitive operations Source code Contents Index

Control.Monad.Primitive Portability non-portable Maintainer Roman Leshchinskiy <rl@cse.unsw.edu.au>

Description

Primitive state-transformer monads

Synopsis

class Monad m => PrimMonad m where type PrimState m primitive :: (State# (PrimState m) -> (#State# (PrimState m), a#)) -> m a internal :: m a -> State# (PrimState m) -> (#State# (PrimState m), a#) data RealWorld primitive_ :: PrimMonad m => (State# (PrimState m) -> State# (PrimState m)) -> m () primToPrim :: (PrimMonad m1, PrimMonad m2, PrimState m1 ~ PrimState m2) => m1 a -> m2 a primToIO :: (PrimMonad m, PrimState m ~ RealWorld) => m a -> IO a primToST :: PrimMonad m => m a -> ST (PrimState m) a unsafePrimToPrim :: (PrimMonad m1, PrimMonad m2) => m1 a -> m2 a unsafePrimToIO :: PrimMonad m => m a -> IO a unsafePrimToST :: PrimMonad m => m a -> ST s a unsafeInlinePrim :: PrimMonad m => m a -> a unsafeInlineIO :: IO a -> a unsafeInlineST :: ST s a -> a touch :: PrimMonad m => a -> m ()

Documentation

class Monad m => PrimMonad m where Source

Class of primitive state-transformer monads Associated Types type PrimState m Source State token type Methods primitive :: (State# (PrimState m) -> (#State# (PrimState m), a#)) -> m a Source Execute a primitive operation internal :: m a -> State# (PrimState m) -> (#State# (PrimState m), a#) Source Expose the internal structure of the monad Instances PrimMonad IO PrimMonad (ST s)

data RealWorld Source

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 Typeable RealWorld

primitive_ :: PrimMonad m => (State# (PrimState m) -> State# (PrimState m)) -> m () Source

Execute a primitive operation with no result

primToPrim :: (PrimMonad m1, PrimMonad m2, PrimState m1 ~ PrimState m2) => m1 a -> m2 a Source

Convert a PrimMonad to another monad with the same state token.

primToIO :: (PrimMonad m, PrimState m ~ RealWorld) => m a -> IO a Source

Convert a PrimMonad with a RealWorld state token to IO

primToST :: PrimMonad m => m a -> ST (PrimState m) a Source

Convert a PrimMonad to ST

unsafePrimToPrim :: (PrimMonad m1, PrimMonad m2) => m1 a -> m2 a Source

Convert a PrimMonad to another monad with a possibly different state token. This operation is highly unsafe!

unsafePrimToIO :: PrimMonad m => m a -> IO a Source

Convert any PrimMonad to IO. This operation is highly unsafe!

unsafePrimToST :: PrimMonad m => m a -> ST s a Source

Convert any PrimMonad to ST with an arbitrary state token. This operations is highly unsafe!

unsafeInlinePrim :: PrimMonad m => m a -> a Source

unsafeInlineIO :: IO a -> a Source

unsafeInlineST :: ST s a -> a Source

touch :: PrimMonad m => a -> m () Source

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