-module Array = ArrayLabels
-module List = ListLabels
-
-module type TREE = sig
+module type S = sig
type ('k, 'v) t
val empty : ('k, 'v) t
val to_dot : ('k, 'v) t -> k_to_string:('k -> string) -> string
end
-
-module BinaryTree : TREE = struct
- type ('k, 'v) t =
- | Node of 'k * 'v * ('k, 'v) t * ('k, 'v) t
- | Leaf
-
- let empty = Leaf
-
- let rec set t ~k ~v =
- match t with
- | Leaf -> Node (k, v, Leaf, Leaf)
- | Node (k', v', l, r) when k < k' -> Node (k', v', set l ~k ~v, r)
- | Node (k', v', l, r) when k > k' -> Node (k', v', l, set r ~k ~v)
- | Node (k, _, l, r) -> Node (k, v, l, r)
-
- let rec get t ~k =
- match t with
- | Leaf -> None
- | Node (k', _, l, _) when k < k' -> get l ~k
- | Node (k', _, _, r) when k > k' -> get r ~k
- | Node (_, v, _, _) -> Some v
-
- let rec member t ~k =
- match t with
- | Leaf -> false
- | Node (k', _, l, _) when k < k' -> member l ~k
- | Node (k', _, _, r) when k > k' -> member r ~k
- | Node _ -> true
-
- let to_edges t =
- let rec to_edges_from k1 t =
- match t with
- | Leaf -> []
- | Node (k2, _, l, r) ->
- (k1, k2) :: ((to_edges_from k2 l) @ (to_edges_from k2 r))
- in
- match t with
- | Leaf -> []
- | Node (k, _, l, r) -> (to_edges_from k l) @ (to_edges_from k r)
-
- let to_dot t ~k_to_string =
- let (edges, _) =
- List.fold_left (to_edges t)
- ~init:("", "\n")
- ~f:(fun (edges, sep) (k1, k2) ->
- let k1, k2 = k_to_string k1, k_to_string k2 in
- (Printf.sprintf "%s%s%S -> %S;\n" edges sep k1 k2, "")
- )
- in
- "digraph G {" ^ edges ^ "}"
-end
-
-let () =
- let tree_a = BinaryTree.empty in
- let tree_a = BinaryTree.set tree_a ~k:"k1" ~v:"v1" in
- let tree_a = BinaryTree.set tree_a ~k:"k2" ~v:"v2" in
- assert (BinaryTree.member tree_a ~k:"k1");
- assert (BinaryTree.member tree_a ~k:"k2");
- assert (Some "v1" = BinaryTree.get tree_a ~k:"k1");
- assert (Some "v2" = BinaryTree.get tree_a ~k:"k2");
- let tree_b =
- Array.fold_left (Sys.argv)
- ~init:BinaryTree.empty
- ~f:(fun t k -> BinaryTree.set t ~k ~v:())
- in
- print_endline (BinaryTree.to_dot tree_b ~k_to_string:(fun x -> x))