open Arg


let input_file : string option ref = ref None
let output_file : string option ref = ref None
let queries = ref []


let set_string_option r s = r := Some s (*pas compris*)

let specs = align [
 
  "-d", String (set_string_option input_file),
        " specify the input document file [default stdin]";
  "--doc", String (set_string_option input_file), " ";
  "-o", String (set_string_option output_file),
        " specify the output file [default stdout]";
  "--out", String (set_string_option output_file), " ";
]

let usage_msg =
  Printf.sprintf "usage: %s [options] query [query ... query]" Sys.argv.(0)

let usage () = usage specs usage_msg

let parse () =
  parse specs (fun q -> queries := q :: !queries ) usage_msg;
  match !queries with
    [] -> raise (Arg.Bad "missing query")
  | l -> queries := List.rev l