[Ur] stateful structure?

[Gergely Buday]

Marc Weber wrote:

> Then you return new state. Because passing state is annoying Haskell
> introduces the State monad. So all you have to do is rewrite the state
> monad in Ur. the init function is then called something like
> "runWithState f initialState"

Adam, is it possible to write a new monad in Ur now? I vaguely
remember that now only the transaction and the signal monad is
supported.

- Gergely