MVar example

MVar.hs

import Control.Concurrent
import Control.Concurrent.MVar

main :: IO ()
main = do
  -- create an empty mvar
  m <- newEmptyMVar
  
  -- get another thread to put a value in it
  forkIO $ putMVar m "A value"
  
  -- take the value
  x <- takeMVar m
  
  putStrLn x