purescript-refs

This module defines functions for working with mutable value references.

Note: Control.Monad.ST provides a safe alternative to Ref when mutation is restricted to a local scope.

Installation

spago install refs

Example

importEffect.RefasRef
main = do-- initialize a new Ref with the value 0
ref <-Ref.new 0-- read from it and check it
curr1 <-Ref.read ref
assertEqual { actual: curr1, expected: 0 }
-- write over the ref with 1Ref.write 1 ref
-- now it is 1 when we read out the value
curr2 <-Ref.read ref
assertEqual { actual: curr2, expected: 1 }
-- modify it by adding 1 to the current stateRef.modify_ (\s -> s + 1) ref
-- now it is 2 when we read out the value
curr3 <-Ref.read ref
assertEqual { actual: curr3, expected: 2 }

See tests to see usages.

Documentation

Module documentation is published on Pursuit.