Modulebase-4.20.2.0Haskell2010

GHC.STRef

References in the ST monad.

datadata STRef s a

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

Example1 expression

>>> :{runST (do    ref <- newSTRef "hello"    x <- readSTRef ref    writeSTRef ref (x ++ "world")    readSTRef ref ):}"helloworld"

Instances1Eq

Eq (STRef s a)Defined in ghc-internal-9.1003.0 · GHC.Internal.STRef
Pointer equality.

valuenewSTRef :: a -> ST s (STRef s a)

Build a new STRef in the current state thread

valuereadSTRef :: STRef s a -> ST s a

Read the value of an STRef

valuewriteSTRef :: STRef s a -> a -> ST s ()

Write a new value into an STRef