val to_string : t -> stringval pair : ('a -> t) -> ('b -> t) -> ('a * 'b) -> tval list : ('a -> t) -> 'a list -> tval option : ('a -> t) -> 'a option -> tval record : (string * t) list -> tval cstr : string -> t list -> tval cstr_record : string -> (string * t) list -> tval cstr_list : string -> ('a -> t) -> 'a list -> tval register_exn_converter : extension_constructor -> (exn -> t) -> unit