(** Operations on positions produced by {!val:Sexpr.read_sexpr} *)

open Sexpr_type
open Lexing

(**/**)

type token = SYM of string | STR of string | NUM of int | LPAR | RPAR | EOF

(**/**)

(** Add position information to a message. *)
val error_msg : position -> string -> string

(** Add position information to a message and fail.
    @raise Failure always *)
val failwith_msg : position -> string -> 'a

(**/**)

val parse_err : position -> string -> 'a

val top : (lexbuf -> token) -> lexbuf -> position sexpr
val one : (lexbuf -> token) -> lexbuf -> position sexpr