Copyright	(c) 2016 Stephen Diehl (c) 2016-2018 Serokell (c) 2018-2023 Kowainik
License	MIT
Maintainer	Kowainik <xrom.xkov@gmail.com>
Stability	Stable
Portability	Portable
Safe Haskell	Safe
Language	Haskell2010

Relude.Lifted.IORef

Description

Lifted reexports from Data.IORef module.

Synopsis

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

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 #

atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b Source #

Lifted version of atomicModifyIORef.

>>> ref <- newIORef 42
>>> atomicModifyIORef ref (\a -> (a, a + 3))
45
>>> readIORef ref
42

To avoid space-leaks, see atomicModifyIORef' for stricter updates
If you are not interested in the return value, see atomicModifyIORef_

atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b Source #

Lifted version of atomicModifyIORef'.

>>> ref <- newIORef 42
>>> atomicModifyIORef' ref (\a -> (a, a + 3))
45
>>> readIORef ref
42

For lazier updates, see atomicModifyIORef
If you are not interested in the return value, see atomicModifyIORef'_

atomicModifyIORef_ :: MonadIO m => IORef a -> (a -> a) -> m () Source #

Version of atomicModifyIORef that discards return value. Useful when you want to update IORef but not interested in the returning result.

>>> ref <- newIORef 42
>>> atomicModifyIORef_ ref (`div` 2)
>>> readIORef ref
21

Since: 0.7.0.0

atomicModifyIORef'_ :: MonadIO m => IORef a -> (a -> a) -> m () Source #

Version of atomicModifyIORef' that discards return value. Useful when you want to update IORef but not interested in the returning result.

>>> ref <- newIORef 42
>>> atomicModifyIORef'_ ref (`div` 2)
>>> readIORef ref
21

Since: 0.7.0.0

atomicWriteIORef :: MonadIO m => IORef a -> a -> m () Source #

Lifted version of atomicWriteIORef.

>>> ref <- newIORef 42
>>> atomicWriteIORef ref 45
>>> readIORef ref
45

modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m () Source #

Lifted version of modifyIORef.

>>> ref <- newIORef 42
>>> modifyIORef ref (\a -> a + 6)
>>> readIORef ref
48

To avoid space-leaks, see modifyIORef' for stricter updates
For atomic updates, see atomicModifyIORef

modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m () Source #

Lifted version of modifyIORef'.

>>> ref <- newIORef 42
>>> modifyIORef' ref (\a -> a + 3)
>>> readIORef ref
45

For lazier updates, see modifyIORef
For atomic updates, see atomicModifyIORef'

newIORef :: MonadIO m => a -> m (IORef a) Source #

Lifted version of newIORef.

>>> ref <- newIORef False
>>> :t ref
ref :: IORef Bool

readIORef :: MonadIO m => IORef a -> m a Source #

Lifted version of readIORef.

>>> ref <- newIORef 42
>>> readIORef ref
42

writeIORef :: MonadIO m => IORef a -> a -> m () Source #

Lifted version of writeIORef.

>>> ref <- newIORef 42
>>> writeIORef ref 43
>>> readIORef ref
43