Safe Haskell	Safe-Inferred
Language	Haskell2010

UnliftIO.IORef

Description

Unlifted Data.IORef.

Since: 0.1.0.0

Synopsis

data IORef a
newIORef :: MonadIO m => a -> m (IORef a)
readIORef :: MonadIO m => IORef a -> m a
writeIORef :: MonadIO m => IORef a -> a -> m ()
modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m ()
modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m ()
atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
atomicWriteIORef :: MonadIO m => IORef a -> a -> m ()
mkWeakIORef :: MonadUnliftIO m => IORef a -> m () -> m (Weak (IORef a))

Documentation

data IORef a #

A mutable variable in the IO monad.

>>> import Data.IORef
>>> r <- newIORef 0
>>> readIORef r
0
>>> writeIORef r 1
>>> readIORef r
1
>>> atomicWriteIORef r 2
>>> readIORef r
2
>>> modifyIORef' r (+ 1)
>>> readIORef r
3
>>> atomicModifyIORef' r (\a -> (a + 1, ()))
>>> readIORef r
4

Instances

Instances details

NFData1 IORef	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> IORef a -> () #
NFData (IORef a)	NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0
Instance details Defined in Control.DeepSeq Methods rnf :: IORef a -> () #
Eq (IORef a)	Pointer equality. Since: base-4.0.0.0
Instance details Defined in GHC.IORef Methods (==) :: IORef a -> IORef a -> Bool # (/=) :: IORef a -> IORef a -> Bool #