sig
val set_chartype : string -> string option
val get_chartype : unit -> string
external is_alpha : char -> bool = "stew_is_alpha"
external is_space : char -> bool = "stew_is_space"
external is_number : char -> bool = "stew_is_number"
external is_lower : char -> bool = "stew_is_lower"
external is_upper : char -> bool = "stew_is_upper"
val is_alphanumeric : char -> bool
external is_punctation : char -> bool = "stew_is_punct"
external is_printable : char -> bool = "stew_is_print"
external is_graphical : char -> bool = "stew_is_graph"
external is_hexadecimal : char -> bool = "stew_is_xdigit"
external to_lower : char -> char = "stew_to_lower"
external to_upper : char -> char = "stew_to_upper"
end