Functor Weak.Make

module Make: functor (H : Hashtbl.HashedType) -> S  with type data = H.t

Functor building an implementation of the weak hash set structure. H.equal can't be the physical equality, since only shallow copies of the elements in the set are given to it.

Parameters:

H : Hashtbl.HashedType

type data

The type of the elements stored in the table.

type t

The type of tables that contain elements of type data. Note that weak hash sets cannot be marshaled using output_value or the functions of the Marshal module.

val create : int -> t

create n creates a new empty weak hash set, of initial size n. The table will grow as needed.

val clear : t -> unit

Remove all elements from the table.

val merge : t -> data -> data

merge t x returns an instance of x found in t if any, or else adds x to t and return x.

val add : t -> data -> unit

add t x adds x to t. If there is already an instance of x in t, it is unspecified which one will be returned by subsequent calls to find and merge.

val remove : t -> data -> unit

remove t x removes from t one instance of x. Does nothing if there is no instance of x in t.

val find : t -> data -> data

find t x returns an instance of x found in t.

Raises Not_found if there is no such element.

val find_opt : t -> data -> data option

find_opt t x returns an instance of x found in t or None if there is no such element.

Since 4.05

val find_all : t -> data -> data list

find_all t x returns a list of all the instances of x found in t.

val mem : t -> data -> bool

mem t x returns true if there is at least one instance of x in t, false otherwise.

val iter : (data -> unit) -> t -> unit

iter f t calls f on each element of t, in some unspecified order. It is not specified what happens if f tries to change t itself.

val fold : (data -> 'a -> 'a) -> t -> 'a -> 'a

fold f t init computes (f d1 (... (f dN init))) where d1 ... dN are the elements of t in some unspecified order. It is not specified what happens if f tries to change t itself.

val count : t -> int

Count the number of elements in the table. count t gives the same result as fold (fun _ n -> n+1) t 0 but does not delay the deallocation of the dead elements.

val stats : t -> int * int * int * int * int * int

Return statistics on the table. The numbers are, in order: table length, number of entries, sum of bucket lengths, smallest bucket length, median bucket length, biggest bucket length.