Direct Haskell translations of the concurrency examples at http://blog.drewolson.org/blog/2013/07/04/clojure-core-dot-async-and-go-a-code-comparison/

ConcurrencyExamples.hs

module ConcurrencyExamples where

import Control.Concurrent
import Control.Concurrent.STM
import Control.Monad
import Control.Applicative
import System.Random

example1 :: IO ()
example1 = do
    forM_ [0..9] $ \i -> forkIO $ do
        threadDelay =<< randomRIO (0, 1000000)
        print i

    threadDelay 2000000

example2 :: IO ()
example2 = do
    c <- newChan
    forM_ [0..9] $ \i -> forkIO $ do
        threadDelay =<< randomRIO (0, 1000000)
        writeChan c i

    replicateM_ 10 $ print =<< readChan c

example3 :: IO ()
example3 = do
    c <- newTChanIO

    forkIO $ do
        threadDelay =<< randomRIO (0, 1000000)
        atomically $ writeTChan c ()

    timeout <- newEmptyTMVarIO
    forkIO $ do
        threadDelay 500000
        atomically $ putTMVar timeout ()

    join . atomically
        $   putStrLn "Got a value!" <$ readTChan c
        <|> putStrLn "Timeout!"     <$ takeTMVar timeout