open CCCanonical_sexp

module T = (val Containers_testlib.make ~__FILE__ ())
include T;;

let csexp_bijective s = to_string s |> parse_string = Ok s;;

eq ~printer:CCFormat.(to_string (Dump.result pp)) (Ok (`List [`Atom ""])) (parse_string {|(0:)|});;
eq ~printer:CCFormat.(to_string (Dump.result pp)) (Ok (`List [`Atom "a"; `Atom "b "])) (parse_string {|(1:a2:b )|});;

t @@ fun () -> csexp_bijective (`List [`Atom ""]);;

let sexp_gen =
  let mkatom a = `Atom a and mklist l = `List l in
  let atom = Q.Gen.(map mkatom (string_size ~gen:char (1 -- 30))) in
  let gen = Q.Gen.(
    sized (fix
      (fun self n st -> match n with
      | 0 -> atom st
      | _ ->
        frequency
          [ 1, atom
          ; 2, map mklist (list_size (0 -- 10) (self (n/10)))
          ] st
      )
  )) in
  let rec small = function
    | `Atom s -> String.length s
    |  `List l -> List.fold_left (fun n x->n+small x) 0 l
  and print = function
    | `Atom s -> Printf.sprintf "`Atom \"%s\"" s
    | `List l -> "`List " ^ Q.Print.list print l
  and shrink = function
    | `Atom s -> Q.Iter.map mkatom (Q.Shrink.string s)
    | `List l -> Q.Iter.map mklist (Q.Shrink.list ~shrink l)
  in
  Q.make ~print ~small ~shrink gen ;;

q ~count:100 sexp_gen csexp_bijective ;;

t @@ fun () -> let s1 =
    `List (CCList.init 100_000
      (fun i -> `List [`Atom "-"; `Atom (string_of_int i); `Atom ")(\n]"])) in
  let str = to_string s1 in
  (match parse_string str with
    | Ok s2 -> assert_equal s1 s2
    | Error e -> assert_failure e);
  true;;