• since 4.12.0:

module type S = sig type key type +!'a t val empty : 'a t val is_empty : 'a t -> bool val mem : key -> 'a t -> bool val add : key -> 'a -> 'a t -> 'a t val update : key -> ('a option -> 'a option) -> 'a t -> 'a t val singleton : key -> 'a -> 'a t val remove : key -> 'a t -> 'a t val merge : (key -> 'a option -> 'b option -> 'c option) -> 'a t -> 'b t -> 'c t val union : (key -> 'a -> 'a -> 'a option) -> 'a t -> 'a t -> 'a t val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool val iter : (key -> 'a -> unit) -> 'a t -> unit val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b val for_all : (key -> 'a -> bool) -> 'a t -> bool val exists : (key -> 'a -> bool) -> 'a t -> bool val filter : (key -> 'a -> bool) -> 'a t -> 'a t val filter_map : (key -> 'a -> 'b option) -> 'a t -> 'b t val partition : (key -> 'a -> bool) -> 'a t -> ('a t * 'a t) val cardinal : 'a t -> int val bindings : 'a t -> (key * 'a) list val min_binding : 'a t -> (key * 'a) val min_binding_opt : 'a t -> (key * 'a) option val max_binding : 'a t -> (key * 'a) val max_binding_opt : 'a t -> (key * 'a) option val choose : 'a t -> (key * 'a) val choose_opt : 'a t -> (key * 'a) option val split : key -> 'a t -> ('a t * 'a option * 'a t) val find : key -> 'a t -> 'a val find_opt : key -> 'a t -> 'a option val find_first : (key -> bool) -> 'a t -> (key * 'a) val find_first_opt : (key -> bool) -> 'a t -> (key * 'a) option val find_last : (key -> bool) -> 'a t -> (key * 'a) val find_last_opt : (key -> bool) -> 'a t -> (key * 'a) option val map : ('a -> 'b) -> 'a t -> 'b t val mapi : (key -> 'a -> 'b) -> 'a t -> 'b t val to_seq : 'a t -> (key * 'a) Seq.t val to_rev_seq : 'a t -> (key * 'a) Seq.t val to_seq_from : key -> 'a t -> (key * 'a) Seq.t val add_seq : (key * 'a) Seq.t -> 'a t -> 'a t val of_seq : (key * 'a) Seq.t -> 'a t end

• since 4.12.0: module Make = Map.Make