val create : ?initial_pos:pos -> unit -> t
add
, add_twice
and add_newline
must be called with strictly increasing offset
values.
val add : t -> offset:int -> unit
int is absolute offset of the position
val add_twice : t -> offset:int -> unit
val add_newline : t -> offset:int -> unit
int is absolute offset of the newline character
val reset : t -> pos -> unit