module Rdf_utf8:sig
..end
val utf8_nb_bytes_of_char : char -> int
val utf8_index_of_char : string -> int -> int
val utf8_char_of_index : string -> int -> int
val utf8_string_length : string -> int
val utf8_char_of_code : int -> string
http://en.wikipedia.org/wiki/UTF-8
.