Moduleeffectful-2.7.1.0GHC2021

Effectful.Prim.IORef

Lifted Data.IORef.

Note: it requires Prim because MutVar from the primitive library is a generalization of IORef.

2 types
10 values

Packageeffectful-2.7.1.0
Exports12
LanguageGHC2021
LicenceBSD-3-Clause
SourceIORef.hs

Effect

1 declaration

datadata Prim (a :: Type -> Type) b

Provide the ability to perform primitive state-transformer actions.

Instances2DispatchOf, StaticRep

type DispatchOf Prim = 'Static 'WithSideEffectsDefined in effectful-core-2.7.1.2 · Effectful.Internal.Monad
data StaticRep Prim
- Prim
Defined in effectful-core-2.7.1.2 · Effectful.Internal.Monad

Handlers

valuerunPrim :: (HasCallStack, IOE :> es) => Eff (Prim ': es) a -> Eff es a

Run an Eff computation with primitive state-transformer actions.

IORef

10 declarations

newtypenewtype IORef a

A mutable variable in the IO monad.

Example11 expressions

>>> import GHC.Internal.Data.IORef>>> r <- newIORef 0>>> readIORef r0>>> writeIORef r 1>>> readIORef r1>>> atomicWriteIORef r 2>>> readIORef r2>>> modifyIORef' r (+ 1)>>> readIORef r3>>> atomicModifyIORef' r (\a -> (a + 1, ()))>>> readIORef r4

See also STRef and MVar.

Instances3NFData1, Eq, NFData

NFData1 IORefDefined in deepseq-1.5.2.0 · Control.DeepSeq
Eq (IORef a)Defined in ghc-internal-10.0.0 · GHC.Internal.IORef
Pointer equality.
NFData (IORef a)Defined in deepseq-1.5.2.0 · Control.DeepSeq
NOTE: Only strict in the reference and not the referenced value.