method range_from_range_in_file ~left ~right =
let from_display = self#mode_from_display (buffer#get_text ()) in
let (left, right) =
let left =
Cam_misc.utf8_string_length
(self#mode_to_display
(String.sub from_display 0 left))
in
let right =
Cam_misc.utf8_string_length
(self#mode_to_display
(String.sub from_display 0 right))
in
(left, right)
in
(left, right)