streamly-0.1.0: examples/parallel-loops.hs

import Control.Applicative ((<|>))
import Control.Concurrent (myThreadId, threadDelay)
import Control.Monad.IO.Class (liftIO)
import System.IO (stdout, hSetBuffering, BufferMode(LineBuffering))
import System.Random (randomIO)
import Streamly

main = runStreamT $ do
    liftIO $ hSetBuffering stdout LineBuffering
    x <- loop "A" <|> loop "B"
    liftIO $ myThreadId >>= putStr . show
             >> putStr " "
             >> print x

    where

    loop name = do
        liftIO $ threadDelay 1000000
        rnd <- liftIO (randomIO :: IO Int)
        return (name, rnd) <|> loop name