SList.Skip
These iterators ignore the default values in the list.
val iter : ( 'a -> unit ) -> 'a t -> unit
val map : ( 'a -> 'b ) -> 'a t -> 'b t
val fold : ( 'a -> 'b -> 'a ) -> 'a -> 'b t -> 'a
val for_all : ( 'a -> bool ) -> 'a t -> bool
val exists : ( 'a -> bool ) -> 'a t -> bool