[greener_grass]

Is there are correct way around?

    St -> (a, St)

vs

    St -> (St, a)

I've found both in the wild and it can be very confusing!

[chuckadams]

The order doesn’t matter as long as you’re consistent, but Control.Monad.State uses the first, and you’ll have a bad time (in Haskell anyway) if you’re not compatible with that.

[RandomThoughts3]

It’s the same thing. Order doesn’t matter in the tuple. Just use a bind which is in line with the signature of the type you want to use.