trace.ml

module rec Value : sig
  type t =
    | Nil
    | Bool of bool
    | Float of float
    | String of string
    | Table of table
  and table = {
    id : int;
    table : t Table.t;
  }
  val hash : t -> int
  val equal : t -> t -> bool
  val make_table : unit -> table
end = struct
  type t =
    | Nil
    | Bool of bool
    | Float of float
    | String of string
    | Table of table
  and table = {
    id : int;
    table : t Table.t;
  }
  let hash = Hashtbl.hash
  let equal x y = match x, y with
    | Nil, Nil -> true
    | Bool x, Bool y -> x = y
    | Float x, Float y -> x = y
    | String x, String y -> x = y
    | Table x, Table y -> x == y
    | _, _ -> false

  let make_table =
    let count = ref 0 in
    fun () -> incr count; { id = !count; table = Table.create 4; }
end
and Table : Hashtbl.S with type key = Value.t = Hashtbl.Make (Value)