val option_map : ('a -> 'a) -> 'a option -> 'a optionval list_map : ('a -> 'a) -> 'a list -> 'a listval pair_map : ('a -> 'a) -> ('b -> 'b) -> ('a * 'b) -> 'a * 'bclass virtual path : object ... endclass virtual paths : object ... endclass virtual module_ : object ... endclass virtual value : object ... endclass virtual class_ : object ... endclass virtual method_ : object ... endclass virtual unit : object ... endclass virtual page : object ... endclass virtual types : object ... end