open Import

(* A functional stack. *)
type 'a t = 'a List.t

let empty = []
let push v t = v :: t
let pop = function [] -> None | x :: ts -> Some (x, ts)
let peek = function [] -> None | x :: _ -> Some x
let pp pp ppf = Fmt.lst pp ppf
let to_list v = v

let jsont e_jsont =
  let stack_of_list lst = List.fold_left (fun acc v -> push v acc) empty lst in
  Jsont.map (Jsont.list e_jsont) ~dec:stack_of_list ~enc:to_list