base-4.3.1.0: Basic libraries

Portabilitynon-portable (uses Control.Monad.ST)
Stabilityexperimental
Maintainerlibraries@haskell.org

Data.STRef

Contents

Description

Mutable references in the (strict) ST monad.

Synopsis

STRefs

data STRef s a Source

a value of type STRef s a is a mutable variable in state thread s, containing a value of type a

Instances

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

Build a new STRef in the current state thread

readSTRef :: STRef s a -> ST s aSource

Read the value of an STRef

writeSTRef :: STRef s a -> a -> ST s ()Source

Write a new value into an STRef

modifySTRef :: STRef s a -> (a -> a) -> ST s ()Source

Mutate the contents of an STRef