Reactive Banana as Library

Main.hs

module Main where

import           Control.Concurrent  (forkIO, threadDelay)
import           Control.Monad       (forever)
import           Data.Time           (getCurrentTime)
import           Reactive.Banana

main = do
    (clock, clockSink) <- newAddHandler
    forkIO $ forever $ getCurrentTime >>= clockSink >> sleep

    (int,    intSink)    <- newAddHandler
    forkIO $ mapM_ ((>> sleep) . intSink) [1..]

    time0 <- getCurrentTime

    library $ do
        clockB <- fromChanges time0 clock
        intB  <- fromChanges 0     int
        return $ liftA2 (\s t -> show s ++ " " ++ show t) clockB intB
  where
     sleep = threadDelay (10^6)

library subnet = do
    network <- compile $ do
        stringE <- changes =<< subnet
        reactimate $ print <$> stringE
    actuate network