Data.STRef

Mutable references in the (strict) ST monad.

STRefs

data STRef s a

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

Instances

Typeable2 STRef

Eq (STRef s a)

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

Build a new STRef in the current state thread

readSTRef :: STRef s a -> ST s a

Read the value of an STRef

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

Write a new value into an STRef

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

Mutate the contents of an STRef