(** The reader's output: syntax, before any typing or macro expansion.

    Deliberately dumb. [true], [false] and [nil] are ordinary symbols here and
    are resolved later; the reader knows nothing about special forms. *)

type t = {
  v   : value;
  loc : Loc.t;
}

and value =
  | Sym   of string        (* foo  rl/draw-fps  .pos  + *)
  | Kw    of string        (* :space  :else                    (leading : dropped) *)
  | Int   of int64         (* 42  -1  0xE6B800FF *)
  | Float of float         (* 0.05 *)
  | Str   of string        (* "SAND" *)
  | Byte  of int           (* \space  \0  \(                   (0..255) *)
  | List  of t list        (* (f x) *)
  | Vec   of t list        (* [1 2 3]  and every binding/type bracket *)
  | Map   of t list        (* {:key v}  in value position, {K V} in type position *)

let make v loc = { v; loc }

let rec to_string f =
  let seq l = String.concat " " (List.map to_string l) in
  match f.v with
  | Sym s   -> s
  | Kw s    -> ":" ^ s
  | Int i   -> Int64.to_string i
  | Float x -> Printf.sprintf "%g" x
  | Str s   -> Printf.sprintf "%S" s
  | Byte b  ->
    (match Char.chr b with
     | ' '  -> "\\space"
     | '\t' -> "\\tab"
     | '\n' -> "\\newline"
     | c    -> Printf.sprintf "\\%c" c)
  | List l  -> "(" ^ seq l ^ ")"
  | Vec l   -> "[" ^ seq l ^ "]"
  | Map l   -> "{" ^ seq l ^ "}"