Source file ASN1_Bitstring.ml

type t = string

let to_int_list bs =
  let len = String.length bs in
  let rec f i res =
    if i >= len then List.rev res else f (i + 1) (Char.code bs.[i] :: res)
  in
  f 0 []
;;

let to_hex_string ?(sep = " ") bs =
  to_int_list bs |> List.map (fun v -> Printf.sprintf "%02X" v) |> String.concat sep
;;

let to_bit_list bs =
  let masks = [ 0x80; 0x40; 0x20; 0x10; 0x08; 0x04; 0x02; 0x01 ] in
  let octet_bits off octet =
    List.mapi (fun i m -> if octet land m > 0 then off + i else -1) masks
    |> List.filter (fun v -> v >= 0)
  in
  to_int_list bs |> List.mapi (fun i v -> octet_bits (i * 8) v) |> List.concat
;;

let to_string bs =
  let hex = to_hex_string bs in
  let bits = to_bit_list bs |> List.map (Printf.sprintf "%d") |> String.concat " " in
  if String.length bits > 0 then hex ^ " BITS(" ^ bits ^ ")" else hex
;;