Module type `CCPersistentHashtbl.S`

type key
type 'a t

val empty : unit -> 'a t: Empty table. The table will be allocated at the first binding.

val create : int -> 'a t: Create a new hashtable, with the given initial capacity.

val is_empty : 'a t -> bool: Is the table empty?

val find : 'a t -> key -> 'a

Find the value for this key, or fails.

raises Not_found: if the key is not present in the table.

val get_exn : key -> 'a t -> 'a: Synonym to find with flipped arguments.

val get : key -> 'a t -> 'a option: Safe version of get_exn.

val mem : 'a t -> key -> bool: Is the key bound?

val length : _ t -> int: Number of bindings.

val add : 'a t -> key -> 'a -> 'a t

Add the binding to the table, returning a new table. The old binding for this key, if it exists, is shadowed and will be restored upon remove tbl k.

since: 0.14

val replace : 'a t -> key -> 'a -> 'a t: Add the binding to the table, returning a new table. This erases the current binding for key, if any.

val update : 'a t -> key -> ('a option -> 'a option) -> 'a t: update tbl key f calls f None if key doesn't belong in tbl, f (Some v) if key -> v otherwise; If f returns None then key is removed, else it returns Some v' and key -> v' is added.

val remove : 'a t -> key -> 'a t: Remove the key.

val copy : 'a t -> 'a t: Fresh copy of the table; the underlying structure is not shared anymore, so using both tables alternatively will be efficient.

val merge : f:(key -> [ `Left of 'a | `Right of 'b | `Both of 'a * 'b ] -> 'c option) -> 'a t -> 'b t -> 'c t: Merge two tables together into a new table. The function's argument correspond to values associated with the key (if present); if the function returns None the key will not appear in the result.

val iter : 'a t -> (key -> 'a -> unit) -> unit: Iterate over bindings.

val fold : ('b -> key -> 'a -> 'b) -> 'b -> 'a t -> 'b: Fold over bindings.

val map : (key -> 'a -> 'b) -> 'a t -> 'b t: Map all values.

val filter : (key -> 'a -> bool) -> 'a t -> 'a t
val filter_map : (key -> 'a -> 'b option) -> 'a t -> 'b t
val for_all : (key -> 'a -> bool) -> 'a t -> bool
val exists : (key -> 'a -> bool) -> 'a t -> bool

Conversions

val of_seq : (key * 'a) sequence -> 'a t: Add (replace) bindings from the sequence to the table.

val of_list : (key * 'a) list -> 'a t
val add_seq : 'a t -> (key * 'a) sequence -> 'a t
val add_list : 'a t -> (key * 'a) list -> 'a t
val to_seq : 'a t -> (key * 'a) sequence: Iter of the bindings of the table.

val to_list : 'a t -> (key * 'a) list

Misc

val equal : 'a equal -> 'a t equal

val pp : ?⁠sep:string -> ?⁠arrow:string -> key printer -> 'a printer -> 'a t printer

val stats : _ t -> Stdlib.Hashtbl.statistics

Statistics on the internal table.

since: 0.14