Hello, Haskellers! I'm relatively new to haskell and due to my strong imperative background, it's really a pain to learn haskell. But I'm really indulged in it. :) Now I think I understand the basics of Haskell very well, such as the type system and monad. And for those data-flow kind of applications, I can easily structure the problem in a functional way and sketch out an intuitive picture of the computation. But for simulation kind-of problems, in which I think OO really fits the best, what's the haskell way to structure such problems? I once thought maybe I can use the State monad to simulate objects. But it's really hard for me to implement, because I think State monad is used to simulate a global shared state, is it right? Then what's the best way to simulate private states or just instead how to solve simulation problems such as a physical engine using the haskell way? Best regards. Eric