containers

A modular, clean and powerful extension of the OCaml standard library
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Library containers
Module CCHash

Definitions

type hash = int

A hash value is a positive integer.

type 'a t = 'a -> hash

A hash function for values of type 'a.

val const : hash -> _ t

const h hashes any value into h. Use with caution!.

val const0 : _ t

Always return 0. Useful for ignoring elements. Example: Hash.(pair string const0) will map pairs ("a", 1) and ("a", 2) to the same hash, but not the same as ("b", 1).

  • since 1.5
val int : int t
val bool : bool t
val char : char t
val int32 : int32 t
val int64 : int64 t
val nativeint : nativeint t
val slice : string -> int -> int t

slice s i len state hashes the slice i, …, i+len-1 of s into state.

val bytes : bytes t

Hash a byte array.

  • since 3.5
val string : string t
val list : 'a t -> 'a list t
val array : 'a t -> 'a array t
val opt : 'a t -> 'a option t
val pair : 'a t -> 'b t -> ('a * 'b) t
val triple : 'a t -> 'b t -> 'c t -> ('a * 'b * 'c) t
val quad : 'a t -> 'b t -> 'c t -> 'd t -> ('a * 'b * 'c * 'd) t
val map : ( 'a -> 'b ) -> 'b t -> 'a t

map f h is the hasher that takes x, and uses h to hash f x.

For example:

module Str_set = Set.Make(String)

let hash_str_set : Str_set.t CCHash.t = CCHash.(map Str_set.to_seq @@ seq string)
  • since 3.5
val if_ : bool -> 'a t -> 'a t -> 'a t

Decide which hash function to use depending on the boolean.

val poly : 'a t

poly x is Hashtbl.hash x. The regular polymorphic hash function.

val list_comm : 'a t -> 'a list t

Commutative version of list. Lists that are equal up to permutation will have the same hash.

  • since 1.0
val array_comm : 'a t -> 'a array t

Commutative version of array. Arrays that are equal up to permutation will have the same hash.

  • since 1.0

Base hash combinators

val combine : 'a t -> hash -> 'a -> hash
val combine2 : hash -> hash -> hash
val combine3 : hash -> hash -> hash -> hash
val combine4 : hash -> hash -> hash -> hash -> hash
val combine5 : hash -> hash -> hash -> hash -> hash -> hash
  • since 2.1
val combine6 : hash -> hash -> hash -> hash -> hash -> hash -> hash
  • since 2.1

Iterators

type 'a iter = ( 'a -> unit ) -> unit
type 'a gen = unit -> 'a option
val seq : 'a t -> 'a Seq.t t
val iter : 'a t -> 'a iter t
val gen : 'a t -> 'a gen t