gistfile1.fs

type BinaryTree =
    |Node of obj * BinaryTree * BinaryTree
    |Empty
    member tree.Traverse f =
        match tree with
            |Node(data, l, r) -> 
                f data
                l.Traverse f
                r.Traverse f
            |Empty -> ()

let tree = Node("Node 1", Node("Node 2", Empty, Empty), Empty)
tree.Traverse (printfn "%A")

> 
"Node 1"
"Node 2"