location.ml

type location =
  | Location of Lexing.position * Lexing.position (** delimited location *)
  | Nowhere (** no location *)

type 'a t = { data : 'a ; loc : location }

let nowhere = Nowhere

let make loc1 loc2 = Location (loc1, loc2)

let of_lex lex =
  Location (Lexing.lexeme_start_p lex, Lexing.lexeme_end_p lex)

let locate ?(loc=Nowhere) x = { data = x; loc = loc }

let print loc ppf =
  match loc with
  | Nowhere ->
      Format.fprintf ppf "unknown location"
  | Location (begin_pos, end_pos) ->
      let begin_char = begin_pos.Lexing.pos_cnum - begin_pos.Lexing.pos_bol in
      let end_char = end_pos.Lexing.pos_cnum - begin_pos.Lexing.pos_bol in
      let begin_line = begin_pos.Lexing.pos_lnum in
      let filename = begin_pos.Lexing.pos_fname in

      if String.length filename != 0 then
        Format.fprintf ppf "file %S, line %d, charaters %d-%d" filename begin_line begin_char end_char
      else
        Format.fprintf ppf "line %d, characters %d-%d" (begin_line - 1) begin_char end_char