| Copyright | (c) Roman Leshchinskiy 2009 |
|---|---|
| License | BSD-style |
| Maintainer | Roman Leshchinskiy <rl@cse.unsw.edu.au> |
| Portability | non-portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Control.Monad.Primitive
Description
Primitive state-transformer monads.
Synopsis
- class Monad m => PrimMonad m where
- data RealWorld
- primitive_ :: PrimMonad m => ( State# ( PrimState m) -> State# ( PrimState m)) -> m ()
- class PrimMonad m => PrimBase m where
- class ( PrimMonad m, s ~ PrimState m) => MonadPrim s m
- class ( PrimBase m, MonadPrim s m) => MonadPrimBase s m
- liftPrim :: ( PrimBase m1, PrimMonad m2, PrimState m1 ~ PrimState m2) => m1 a -> m2 a
- primToPrim :: ( PrimBase m1, PrimMonad m2, PrimState m1 ~ PrimState m2) => m1 a -> m2 a
- primToIO :: ( PrimBase m, PrimState m ~ RealWorld ) => m a -> IO a
- primToST :: PrimBase m => m a -> ST ( PrimState m) a
- ioToPrim :: ( PrimMonad m, PrimState m ~ RealWorld ) => IO a -> m a
- stToPrim :: PrimMonad m => ST ( PrimState m) a -> m a
- unsafePrimToPrim :: ( PrimBase m1, PrimMonad m2) => m1 a -> m2 a
- unsafePrimToIO :: PrimBase m => m a -> IO a
- unsafePrimToST :: PrimBase m => m a -> ST s a
- unsafeIOToPrim :: PrimMonad m => IO a -> m a
- unsafeSTToPrim :: PrimMonad m => ST s a -> m a
- unsafeInlinePrim :: PrimBase m => m a -> a
- unsafeInlineIO :: IO a -> a
- unsafeInlineST :: ST s a -> a
- touch :: PrimMonad m => a -> m ()
- evalPrim :: forall a m. PrimMonad m => a -> m a
- unsafeInterleave :: PrimBase m => m a -> m a
- unsafeDupableInterleave :: PrimBase m => m a -> m a
- noDuplicate :: PrimMonad m => m ()
Documentation
class Monad m => PrimMonad m where Source #
Class of monads which can perform primitive state-transformer actions.
Methods
primitive :: ( State# ( PrimState m) -> (# State# ( PrimState m), a #)) -> m a Source #
Execute a primitive operation.
Instances
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#
.
primitive_ :: PrimMonad m => ( State# ( PrimState m) -> State# ( PrimState m)) -> m () Source #
Execute a primitive operation with no result.
class PrimMonad m => PrimBase m where Source #
Class of primitive monads for state-transformer actions.
Unlike
PrimMonad
, this typeclass requires that the
Monad
be fully
expressed as a state transformer, therefore disallowing other monad
transformers on top of the base
IO
or
ST
.
Since: 0.6.0.0
Methods
internal :: m a -> State# ( PrimState m) -> (# State# ( PrimState m), a #) Source #
Expose the internal structure of the monad.
class ( PrimMonad m, s ~ PrimState m) => MonadPrim s m Source #
class ( PrimBase m, MonadPrim s m) => MonadPrimBase s m Source #
PrimBase'
s state token type can be annoying to handle
in constraints. This typeclass lets users (visually) notice
PrimState
equality constraints less, by witnessing that
s ~
.
PrimState
m
Instances
| ( PrimBase m, MonadPrim s m) => MonadPrimBase s m Source # | |
|
Defined in Control.Monad.Primitive |
|
primToPrim :: ( PrimBase m1, PrimMonad m2, PrimState m1 ~ PrimState m2) => m1 a -> m2 a Source #
Convert a
PrimBase
to another monad with the same state token.
unsafePrimToPrim :: ( PrimBase m1, PrimMonad m2) => m1 a -> m2 a Source #
Convert a
PrimBase
to another monad with a possibly different state
token. This operation is highly unsafe!
unsafePrimToIO :: PrimBase m => m a -> IO a Source #
unsafePrimToST :: PrimBase m => m a -> ST s a Source #
unsafeIOToPrim :: PrimMonad m => IO a -> m a Source #
unsafeSTToPrim :: PrimMonad m => ST s a -> m a Source #
unsafeInlinePrim :: PrimBase m => m a -> a Source #
See
unsafeInlineIO
. This function is not recommended for the same
reasons.
unsafeInlineIO :: IO a -> a Source #
Generally, do not use this function. It is the same as
accursedUnutterablePerformIO
from
bytestring
and is well behaved under
narrow conditions. See the documentation of that function to get an idea
of when this is sound. In most cases
GHC.IO.Unsafe.unsafeDupablePerformIO
should be preferred.
unsafeInlineST :: ST s a -> a Source #
See
unsafeInlineIO
. This function is not recommended for the same
reasons. Prefer
runST
when
s
is free.
evalPrim :: forall a m. PrimMonad m => a -> m a Source #
Create an action to force a value; generalizes
evaluate
Since: 0.6.2.0
unsafeInterleave :: PrimBase m => m a -> m a Source #
unsafeDupableInterleave :: PrimBase m => m a -> m a Source #
noDuplicate :: PrimMonad m => m () Source #