Modulebasement-0.0.16Haskell2010

Basement.Monad

Allow to run operation in ST and IO, without having to distinguinsh between the two. Most operations exposes the bare nuts and bolts of how IO and ST actually works, and relatively easy to shoot yourself in the foot

this is highly similar to the Control.Monad.Primitive in the primitive package

2 classes
6 values

Packagebasement-0.0.16
Exports8
LanguageHaskell2010
LicenceBSD-3-Clause
SourceMonad.hs

classclass (Functor m, Applicative m, Monad m) => PrimMonad (m :: Type -> Type) where

Primitive monad that can handle mutation.

For example: IO and ST.

Associated types

type family PrimState (m :: Type -> Type)
type of state token associated with the PrimMonad m
type family PrimVar (m :: Type -> Type) :: Type -> Type
type of variable associated with the PrimMonad m

Methods

primitive :: (State# (PrimState m) -> (# State# (PrimState m), a #)) -> m a
Unwrap the State# token to pass to a function a primitive function that returns an unboxed state and a value.
primThrow :: Exception e => e -> m a
Throw Exception in the primitive monad
unPrimMonad :: m a -> State# (PrimState m) -> (# State# (PrimState m), a #)
Run a Prim monad from a dedicated state#
primVarNew :: a -> m (PrimVar m a)
Build a new variable in the Prim Monad
primVarRead :: PrimVar m a -> m a
Read the variable in the Prim Monad
primVarWrite :: PrimVar m a -> a -> m ()
Write the variable in the Prim Monad

Instances2PrimMonad

PrimMonad IODefined in basement-0.0.16 · Basement.Monad
PrimMonad (ST s)Defined in basement-0.0.16 · Basement.Monad

classclass Monad m => MonadFailure (m :: Type -> Type) where

Monad that can represent failure

Similar to MonadFail but with a parametrized Failure linked to the Monad

Associated types

type family Failure (m :: Type -> Type)
The associated type with the MonadFailure, representing what failure can be encoded in this monad

Methods

mFail :: Failure m -> m ()
Raise a Failure through a monad.

Instances3MonadFailure

MonadFailure MaybeDefined in basement-0.0.16 · Basement.Monad
MonadFailure (Either a)Defined in basement-0.0.16 · Basement.Monad
Monad state => MonadFailure (Builder collection mutCollection step state err)Defined in basement-0.0.16 · Basement.MutableBuilder

valueunPrimMonad_

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

just like unwrapPrimMonad but throw away the result and return just the new State#

valueunsafePrimCast :: (PrimMonad m1, PrimMonad m2) => m1 a -> m2 a

Convert a prim monad to another prim monad.

The net effect is that it coerce the state repr to another, so the runtime representation should be the same, otherwise hilary ensues.

valueunsafePrimToST :: PrimMonad prim => prim a -> ST s a

Convert any prim monad to an ST monad

valueunsafePrimToIO :: PrimMonad prim => prim a -> IO a

Convert any prim monad to an IO monad

valueunsafePrimFromIO :: PrimMonad prim => IO a -> prim a

Convert any IO monad to a prim monad

valueprimTouch :: PrimMonad m => a -> m ()

Touch primitive lifted to any prim monad