[Haskell-cafe] question about interruptable state runner

Hello. I'm writing a small tcp server with that can handle connections and answer by rules writen in a small script that can be interpreted by server. For this purpose I've written an interpreter that has type ErrorT MyError (StateT ScriptState IO) so I can call "native" IO function in that script, and define new one. I can run this script with runState (runErrorT (...)) oldState. But there is one problem: in script i should be able to call functions that will stop script interpretation and wait for some server event. To continue interpretation. Can smb give an advice what is the best way to do it? -- Best regards Alexander V Vershilov