val is_empty : 'a t -> boolval singleton : key -> 'a -> 'a tval find_opt : key -> 'a t -> 'a optionval mapi : (key -> 'a -> 'a) -> 'a t -> 'a tval union : (key -> 'a -> 'a -> 'a option) -> 'a t -> 'a t -> 'a tval merge :
(key -> 'a option -> 'b option -> 'c option) ->
'a t ->
'b t ->
'c tval for_all : (key -> 'a -> bool) -> 'a t -> boolval iter : (key -> 'a -> unit) -> 'a t -> unitval fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'bval pp :
(Stdlib.Format.formatter -> 'a -> unit) ->
Stdlib.Format.formatter ->
'a t ->
unit