error

    Couldn't match expected type ‘IO () -> m a0’
                with actual type ‘IO ()’
    Relevant bindings include
      eioServer :: ServerState
                   -> Data.Pool.Pool Database.RethinkDB.Network.RethinkDBHandle
                   -> m ()
        (bound at Api/Lib/Chat.hs:80:1)
    The first argument of ($) takes one argument,
    but its type ‘IO ()’ has none
    In a stmt of a 'do' block:
      threadDelay 5000
      $ do { c <- next cursor;
             case c of {
               Nothing -> print "Nothing one"
               Just x -> do { ... } } }
    In the expression:
      do { userNameMVar <- liftIO STM.newEmptyTMVarIO;
           let forUserName m
                 = liftIO (STM.atomically (STM.tryReadTMVar userNameMVar))
                   >>= mapM_ m;
           cursor <- liftIO $ User.listRawChanges pool;
           threadDelay 5000
           $ do { c <- next cursor;
                  case c of {
                    Nothing -> ...
                    Just x -> ... } };
           .... }

Main.hs

cursor <- liftIO $ User.listRawChanges pool

threadDelay 5000 $ do
  c <- next cursor
  case c of
      Nothing -> print "Nothing"
      Just x -> do
          let u = resultToMaybe $ fromDatum x :: Maybe [SecureUser]
          case u of
              Nothing -> print "Nothing"
              Just users -> print users