module type S = sig .. end
type key
type +'a t
val is_empty : 'a t -> bool
val mem : key -> 'a t -> bool
val add : key:key ->
data:'a -> 'a t -> 'a t
val singleton : key -> 'a -> 'a t
val remove : key -> 'a t -> 'a t
val merge : f:(key -> 'a option -> 'b option -> 'c option) ->
'a t -> 'b t -> 'c t
val compare : cmp:('a -> 'a -> int) ->
'a t -> 'a t -> int
val equal : cmp:('a -> 'a -> bool) ->
'a t -> 'a t -> bool
val iter : f:(key:key -> data:'a -> unit) ->
'a t -> unit
val fold : f:(key:key -> data:'a -> 'b -> 'b) ->
'a t -> init:'b -> 'b
val for_all : f:(key -> 'a -> bool) -> 'a t -> bool
val exists : f:(key -> 'a -> bool) -> 'a t -> bool
val filter : f:(key -> 'a -> bool) ->
'a t -> 'a t
val partition : f:(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 max_binding : 'a t -> key * 'a
val choose : 'a t -> key * 'a
val split : key ->
'a t ->
'a t * 'a option * 'a t
val find : key -> 'a t -> 'a
val map : f:('a -> 'b) -> 'a t -> 'b t
val mapi : f:(key -> 'a -> 'b) ->
'a t -> 'b t