Hello,

I am facing a little problem here. Let's say that I have a tree :

type 'a Node =
|Leaf of 'a
|Node of ('a Node * 'a * 'a Node)
|Empty

and I would like to visit it using a 'walk' function written in CPS:

let rec walk tree k =
match tree with
|Empty -> k Empty
|Leaf x -> k (Leaf x)
|Node (l, x, r) -> let k1 nl nr = k (Node (nl, x, nr))
let k2 nl = walk r (k1 nl)
walk l k2

Now, my question is: is it possible to re-write 'walk' using the continuation workflow so that recursive calls to 'walk' are still in tail position. I have tried but I do not see clearly any solution.

Thank you

Regards

J-C