val add : key:key -> data:'a -> 'a t -> 'a tval iter : f:(key:key -> data:'a -> unit) -> 'a t -> unitval map : f:('a -> 'b) -> 'a t -> 'b tval mapi : f:(key:key -> data:'a -> 'b) -> 'a t -> 'b tval filterv : f:('a -> bool) -> 'a t -> 'a tval filter : f:(key -> 'a -> bool) -> 'a t -> 'a tval fold : f:(key:key -> data:'a -> 'b -> 'b) -> 'a t -> init:'b -> 'bval compare : cmp:('a -> 'a -> int) -> 'a t -> 'a t -> intval equal : cmp:('a -> 'a -> bool) -> 'a t -> 'a t -> bool