`sig
val from_gen : char Gen.t -> Sedlexing.lexbuf
val from_channel : Stdlib.in_channel -> Sedlexing.lexbuf
val from_string : string -> Sedlexing.lexbuf
val lexeme : Sedlexing.lexbuf -> string
val sub_lexeme : Sedlexing.lexbuf -> int -> int -> string
module Helper :
sig
val width : char -> int
val check_two : int -> int -> int
val check_three : int -> int -> int -> int
val check_four : int -> int -> int -> int -> int
end
end`