ocaml_4.04_tail_call_tree_parse.ml

type 'a tree =
| Leaf of 'a
| Node of 'a * 'a tree * 'a tree;;

let t = Node (6, (Node (7, (Leaf 1), (Leaf 2))), (Node (8, (Leaf 3), (Leaf 4))));;

let rec parse t =
  let rec parse_trees trees acc = match trees with
  | [] -> acc
  | (Leaf i) :: tl -> parse_trees tl (i + acc)
  | (Node (i, l, r)) :: tl -> parse_trees (l :: r :: tl) (acc + i)
  in
  parse_trees [t] 0;;