module Control.Concurrent.STM.Util where

import Control.Monad.IO.Class
import Control.Concurrent.STM

chanContents :: TChan x -> IO [x]
chanContents ch = do
        x  <- atomically $ do
            bempty <- isEmptyTChan ch
            if bempty
                then return Nothing
                else fmap Just $ readTChan ch
        maybe (return [])
              (\x -> do
                xs <- chanContents ch
                return (x:xs))
              x

ioWriteChan :: MonadIO m => TChan a -> a -> m ()
ioWriteChan c v = liftIO . atomically $ writeTChan c v