Data.Mutable.PRef

Use ByteArrays containing one element for mutable references.

This is similar to URefs, but avoids the overhead of storing the length of the Vector, which we statically know will always be 1. This allows it to be a bit faster.

Motivated by: http://stackoverflow.com/questions/27261813/why-is-my-little-stref-int-require-allocating-gigabytes and ArrayRef.

Types

data PRef s a

A primitive ByteArray reference, supporting any monad.

Instances

Prim a => MutableRef (PRef s a)

MutableContainer (PRef s a)

type RefElement (PRef s a) = a

type MCState (PRef s a) = s

type IOPRef = PRef (PrimState IO)

A primitive ByteArray IO reference.

Functions

asPRef :: PRef s a -> PRef s a

class MutableContainer c => MutableRef c where

Associated Types

type RefElement c

Methods

newRef :: (PrimMonad m, PrimState m ~ MCState c) => RefElement c -> m c

readRef :: (PrimMonad m, PrimState m ~ MCState c) => c -> m (RefElement c)

writeRef :: (PrimMonad m, PrimState m ~ MCState c) => c -> RefElement c -> m ()

modifyRef :: (PrimMonad m, PrimState m ~ MCState c) => c -> (RefElement c -> RefElement c) -> m ()

modifyRef' :: (PrimMonad m, PrimState m ~ MCState c) => c -> (RefElement c -> RefElement c) -> m ()

Instances

MutableRef (IORef a)

MutableRef (STRef s a)

MutableRef (MutVar s a)

Unbox a => MutableRef (URef s a)

Prim a => MutableRef (PRef s a)

MutableRef (VRef s a)

Storable a => MutableRef (SRef s a)