Why Haskell helps with reusability

ApplicationSpecific.hs

-- First, I made it application specific
attemptConnect :: Int -> TWInfo -> Manager -> APIRequest apiName responseType -> ResourceT IO (ResumableSource (ResourceT IO) StreamingAPI)
attemptConnect delay twInfo mgr = do
    ms <- streamShowStatus twInfo mgr (statusesFilter accountName [accountID])
    case ms of
      Just s -> return s
      Nothing -> do
        liftIO $ putStrLn ("FAILED, delaying for " <> show delay <> "s")
        liftIO $ threadDelay (delay * 1000 * 1000)
        attemptConnect (delay*2) twInfo mgr
        
-- retries with a delay, can be used for any monadic action that returns (Maybe a)
-- will keep trying until it gets a value
-- EXAMPLE: 
-- retryWithDelay 60 (*2) $ streamShowStatus twInfo mgr (statusFilter accountName [accountID])
retryWithDelay :: MonadIO m => Int -> (Int -> Int) -> m (Maybe a) -> m a
retryWithDelay delay grow action = do
    ma <- action
    case ma of
      Just a -> return a
      Nothing -> do
        liftIO $ putStrLn ("FAILED, delaying for " <> show delay <> "s")
        liftIO $ threadDelay (delay * 1000 * 1000)
        retryWithDelay (grow delay) grow action