(************************************************************
   counter2.ml		Created      : Fri Aug  8 20:16:18 2003
  			Last modified: Fri Aug 08 21:01:34 2003
  Compile: ocamlc counter2.ml -o counter2 #
  FTP Directory: sources/ocaml #
  Reference: http://www002.upp.so-net.ne.jp/mamewo/sources/scheme/counter.scm
************************************************************)
(*  recursive な Variant 型で再帰型を模倣するのじゃ *)

type recursive_function = Rec of (unit -> (int * recursive_function))

let rec counter_new init = (init, Rec (fun () -> (counter_new (init + 1))))
let counter_value (v, _) = v
let counter_increment (_, Rec f) = f ()

let _ =
  print_int (counter_value (counter_increment (counter_increment (counter_increment (counter_new 1)))));
  print_newline ()