package containers

  1. Overview
  2. Docs
package containers
Legend:
Library
Module
Module type
Parameter
Class
Class type

Array utils

type 'a sequence = ('a -> unit) -> unit
type 'a klist = unit -> [ `Nil | `Cons of 'a * 'a klist ]
type 'a gen = unit -> 'a option
type 'a equal = 'a -> 'a -> bool
type 'a ord = 'a -> 'a -> int
type 'a random_gen = Random.State.t -> 'a

Abstract Signature

module type S = sig ... end

Arrays

type 'a t = 'a array
include S with type 'a t := 'a t
val empty : 'a t
val equal : 'a equal -> 'a t equal
val compare : 'a ord -> 'a t ord
val get : 'a t -> int -> 'a
val get_safe : 'a t -> int -> 'a option

get_safe a i returns Some a.(i) if i is a valid index

  • since 0.18
val set : 'a t -> int -> 'a -> unit
val length : _ t -> int
val fold : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a
val foldi : ('a -> int -> 'b -> 'a) -> 'a -> 'b t -> 'a

Fold left on array, with index

val fold_while : ('a -> 'b -> 'a * [ `Stop | `Continue ]) -> 'a -> 'b t -> 'a

Fold left on array until a stop condition via ('a, `Stop) is indicated by the accumulator

  • since 0.8
val iter : ('a -> unit) -> 'a t -> unit
val iteri : (int -> 'a -> unit) -> 'a t -> unit
val blit : 'a t -> int -> 'a t -> int -> int -> unit

blit from i into j len copies len elements from the first array to the second. See Array.blit.

val reverse_in_place : 'a t -> unit

Reverse the array in place

val sorted : ('a -> 'a -> int) -> 'a t -> 'a array

sorted cmp a makes a copy of a and sorts it with cmp.

  • since 0.21
val sort_indices : ('a -> 'a -> int) -> 'a t -> int array

sort_indices cmp a returns a new array b, with the same length as a, such that b.(i) is the index of the i-th element of a in sort cmp a. In other words, map (fun i -> a.(i)) (sort_indices a) = sorted cmp a. a is not modified.

  • since 0.21
val sort_ranking : ('a -> 'a -> int) -> 'a t -> int array

sort_ranking cmp a returns a new array b, with the same length as a, such that b.(i) is the position in sorted cmp a of the i-th element of a. a is not modified.

In other words, map (fun i -> (sorted cmp a).(i)) (sort_ranking cmp a) = a.

Without duplicates, we also have lookup_exn a.(i) (sorted a) = (sorted_ranking a).(i)

  • since 0.21
val find : ('a -> 'b option) -> 'a t -> 'b option

find f a returns Some y if there is an element x such that f x = Some y, else it returns None

val findi : (int -> 'a -> 'b option) -> 'a t -> 'b option

Like find, but also pass the index to the predicate function.

  • since 0.3.4
val find_idx : ('a -> bool) -> 'a t -> (int * 'a) option

find_idx p x returns Some (i,x) where x is the i-th element of l, and p x holds. Otherwise returns None

  • since 0.3.4
val lookup : ?cmp:'a ord -> 'a -> 'a t -> int option

Lookup the index of some value in a sorted array.

  • returns

    None if the key is not present, or Some i (i the index of the key) otherwise

val lookup_exn : ?cmp:'a ord -> 'a -> 'a t -> int

Same as lookup_exn, but

  • raises Not_found

    if the key is not present

val bsearch : ?cmp:('a -> 'a -> int) -> 'a -> 'a t -> [ `All_lower | `All_bigger | `Just_after of int | `Empty | `At of int ]

bsearch ?cmp x arr finds the index of the object x in the array arr, provided arr is sorted using cmp. If the array is not sorted, the result is not specified (may raise Invalid_argument).

Complexity: O(log n) where n is the length of the array (dichotomic search).

  • returns
    • `At i if cmp arr.(i) x = 0 (for some i)
    • `All_lower if all elements of arr are lower than x
    • `All_bigger if all elements of arr are bigger than x
    • `Just_after i if arr.(i) < x < arr.(i+1)
    • `Empty if the array is empty
  • raises Invalid_argument

    if the array is found to be unsorted w.r.t cmp

  • since 0.13
val for_all : ('a -> bool) -> 'a t -> bool
val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool

Forall on pairs of arrays.

  • raises Invalid_argument

    if they have distinct lengths allow different types

    @since 0.20

val exists : ('a -> bool) -> 'a t -> bool
val exists2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool

Exists on pairs of arrays.

  • raises Invalid_argument

    if they have distinct lengths allow different types

    @since 0.20

val fold2 : ('acc -> 'a -> 'b -> 'acc) -> 'acc -> 'a t -> 'b t -> 'acc

Fold on two arrays stepwise.

  • raises Invalid_argument

    if they have distinct lengths

  • since 0.20
val iter2 : ('a -> 'b -> unit) -> 'a t -> 'b t -> unit

Iterate on two arrays stepwise.

  • raises Invalid_argument

    if they have distinct lengths

  • since 0.20
val shuffle : 'a t -> unit

Shuffle randomly the array, in place

val shuffle_with : Random.State.t -> 'a t -> unit

Like shuffle but using a specialized random state

val random_choose : 'a t -> 'a random_gen

Choose an element randomly.

  • raises Not_found

    if the array/slice is empty

val to_seq : 'a t -> 'a sequence
val to_gen : 'a t -> 'a gen
val to_klist : 'a t -> 'a klist

IO

val pp : ?sep:string -> (Buffer.t -> 'a -> unit) -> Buffer.t -> 'a t -> unit

Print an array of items with printing function

val pp_i : ?sep:string -> (Buffer.t -> int -> 'a -> unit) -> Buffer.t -> 'a t -> unit

Print an array, giving the printing function both index and item

val print : ?sep:string -> (Format.formatter -> 'a -> unit) -> Format.formatter -> 'a t -> unit

Print an array of items with printing function

val map : ('a -> 'b) -> 'a t -> 'b t
val map2 : ('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t

Map on two arrays stepwise.

  • raises Invalid_argument

    if they have distinct lengths

  • since 0.20
val rev : 'a t -> 'a t

Copy + reverse in place

  • since 0.20
val filter : ('a -> bool) -> 'a t -> 'a t

Filter elements out of the array. Only the elements satisfying the given predicate will be kept.

val filter_map : ('a -> 'b option) -> 'a t -> 'b t

Map each element into another value, or discard it

val flat_map : ('a -> 'b t) -> 'a t -> 'b array

Transform each element into an array, then flatten

val (>>=) : 'a t -> ('a -> 'b t) -> 'b t

Infix version of flat_map

val (>>|) : 'a t -> ('a -> 'b) -> 'b t

Infix version of map

  • since 0.8
val (>|=) : 'a t -> ('a -> 'b) -> 'b t

Infix version of map

  • since 0.8
val except_idx : 'a t -> int -> 'a list

Remove given index, obtaining the list of the other elements

val (--) : int -> int -> int t

Range array

val (--^) : int -> int -> int t

Range array, excluding right bound

  • since 0.17
val random : 'a random_gen -> 'a t random_gen
val random_non_empty : 'a random_gen -> 'a t random_gen
val random_len : int -> 'a random_gen -> 'a t random_gen

Slices

A slice is a part of an array, that requires no copying and shares its storage with the original array.

All indexing in a slice is relative to the beginning of a slice, not to the underlying array (meaning a slice is effectively like a regular array)

module Sub : sig ... end

Generic Functions

module type MONO_ARRAY = sig ... end
val sort_generic : (module MONO_ARRAY with type elt = 'elt and type t = 'arr) -> ?cmp:('elt -> 'elt -> int) -> 'arr -> unit

Sort the array, without allocating (eats stack space though). Performance might be lower than Array.sort.

  • since 0.14