(******************************************************************************)
(*  ocaml-fileutils: files and filenames common operations                    *)
(*                                                                            *)
(*  Copyright (C) 2003-2014, Sylvain Le Gall                                  *)
(*                                                                            *)
(*  This library is free software; you can redistribute it and/or modify it   *)
(*  under the terms of the GNU Lesser General Public License as published by  *)
(*  the Free Software Foundation; either version 2.1 of the License, or (at   *)
(*  your option) any later version, with the OCaml static compilation         *)
(*  exception.                                                                *)
(*                                                                            *)
(*  This library is distributed in the hope that it will be useful, but       *)
(*  WITHOUT ANY WARRANTY; without even the implied warranty of                *)
(*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the file         *)
(*  COPYING for more details.                                                 *)
(*                                                                            *)
(*  You should have received a copy of the GNU Lesser General Public License  *)
(*  along with this library; if not, write to the Free Software Foundation,   *)
(*  Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA             *)
(******************************************************************************)

(** Manipulate path extension
  *)

let get fn =
  let start_pos =
    (String.rindex fn '.') + 1
  in
  let fn_len =
    String.length fn
  in
    if start_pos = fn_len then
      ""
    else
      String.sub fn start_pos (fn_len - start_pos)


let check fn ext =
  try
    (get fn) = ext
  with Not_found ->
    false


let chop fn =
  try
    let end_pos =
      String.rindex fn '.'
    in
      if end_pos = 0 then
        ""
      else
        String.sub fn 0 end_pos
  with Not_found ->
    fn


let add fn ext =
  fn ^ "." ^ ext


let replace fn ext =
  add (chop fn) ext