{-# LANGUAGE
MultiParamTypeClasses,
FlexibleInstances,
UndecidableInstances
#-}
module Data.StateRef.Instances.Undecidable where
import Data.StateRef.Types
newtype UnsafeModifyRef sr = UnsafeModifyRef sr
instance ReadRef sr m a => ReadRef (UnsafeModifyRef sr) m a where
readReference :: UnsafeModifyRef sr -> m a
readReference (UnsafeModifyRef sr
sr) = sr -> m a
forall sr (m :: * -> *) a. ReadRef sr m a => sr -> m a
readReference sr
sr
instance WriteRef sr m a => WriteRef (UnsafeModifyRef sr) m a where
writeReference :: UnsafeModifyRef sr -> a -> m ()
writeReference (UnsafeModifyRef sr
sr) = sr -> a -> m ()
forall sr (m :: * -> *) a. WriteRef sr m a => sr -> a -> m ()
writeReference sr
sr
instance (Monad m, ReadRef sr m a, WriteRef sr m a) => ModifyRef (UnsafeModifyRef sr) m a where
atomicModifyReference :: UnsafeModifyRef sr -> (a -> (a, b)) -> m b
atomicModifyReference = UnsafeModifyRef sr -> (a -> (a, b)) -> m b
forall (m :: * -> *) sr t a b.
(Monad m, ReadRef sr m t, WriteRef sr m a) =>
sr -> (t -> (a, b)) -> m b
defaultAtomicModifyReference
modifyReference :: UnsafeModifyRef sr -> (a -> a) -> m ()
modifyReference = UnsafeModifyRef sr -> (a -> a) -> m ()
forall (m :: * -> *) sr t a.
(Monad m, ReadRef sr m t, WriteRef sr m a) =>
sr -> (t -> a) -> m ()
defaultModifyReference