Data.OpenWitness.ST

This is an approximate re-implementation of Control.Monad.ST and Data.STRef using open witnesses.

The ST Monad

type ST s = StateT (WitnessDict (OpenWitness s)) (OW s)

runST :: (forall s. ST s a) -> a

fixST :: (a -> ST s a) -> ST s a

Converting ST to OW and IO

stToOW :: ST s a -> OW s a

data RealWorld

The s type for running OW in IO.

stToIO :: ST RealWorld a -> IO a

STRefs

type STRef s = OpenWitness s

newSTRef :: a -> ST s (STRef s a)

readSTRef :: STRef s a -> ST s a

writeSTRef :: forall s a. STRef s a -> a -> ST s ()

modifySTRef :: forall s a. STRef s a -> (a -> a) -> ST s ()