How do functional language gui bindings work?

Do they typically use non functional aspects of the language (including mutable v开发者_如何学Pythonariables). Are there other strategies? Could you describe them?

Do they typically use non functional aspects of the language (including mutable variables)

Many do, yes. In case of haskell, which doesn't have mutable variables or functions with side-effects, they use the IO monad (which is haskell's way of encapsulating side-effects)-

Are there other strategies? Could you describe them?

Yes, there are. Look at functional reactive programming.