Re: polymorphic type in state of state monad

G'day all. On Tue, Mar 11, 2003 at 08:34:06AM +1300, Tom Pledger wrote:

If, on the other hand, you want to vary the state type *during* a single monadic computation, it gets messy. You could try one of the following.

Very often, you just want to vary the state type for some portion of the computation then go back to the original. In that case, a simpler solution is to stack a new state monad transformer (such as Control.Monad.State.StateT) on top of your existing state monad for the part where you need it. Cheers, Andrew Bromage