Hello haskell-cafe, just another interesting discussion in russian forum raised such idea: we all say that monads are the haskell way to do i/o. is it true? may be, uniqueness types, just like in Clean and Mercury, are real way, and monads are only the way to write programs that use uniqueness types easier? so, IO monad is like any other monad - it simplifies writing of complex code, but by itself it don't solve any problems. all code that can be written with monads can also be written using ordinal function calls. we know it for IO monad too - in ghc, we can use low-level representation of IO type and write imperative code without use of any monad operators -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com