Module `CCArray`

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 = Stdlib.Random.State.t -> 'a
type 'a printer = Stdlib.Format.formatter -> 'a -> unit

Arrays

include module type of CCShimsArray_

include Stdlib.Array

type 'a t = 'a array

val length : 'a array -> int
val get : 'a array -> int -> 'a
val set : 'a array -> int -> 'a -> unit
val make : int -> 'a -> 'a array
val create : int -> 'a -> 'a array
val create_float : int -> float array

val make_float : int -> float array
val init : int -> (int -> 'a) -> 'a array
val make_matrix : int -> int -> 'a -> 'a array array
val create_matrix : int -> int -> 'a -> 'a array array
val append : 'a array -> 'a array -> 'a array
val concat : 'a array list -> 'a array
val sub : 'a array -> int -> int -> 'a array
val copy : 'a array -> 'a array
val fill : 'a array -> int -> int -> 'a -> unit
val blit : 'a array -> int -> 'a array -> int -> int -> unit
val to_list : 'a array -> 'a list
val of_list : 'a list -> 'a array
val iter : ('a -> unit) -> 'a array -> unit
val iteri : (int -> 'a -> unit) -> 'a array -> unit
val map : ('a -> 'b) -> 'a array -> 'b array
val mapi : (int -> 'a -> 'b) -> 'a array -> 'b array
val fold_left : ('a -> 'b -> 'a) -> 'a -> 'b array -> 'a
val fold_right : ('b -> 'a -> 'a) -> 'b array -> 'a -> 'a
val iter2 : ('a -> 'b -> unit) -> 'a array -> 'b array -> unit
val map2 : ('a -> 'b -> 'c) -> 'a array -> 'b array -> 'c array
val for_all : ('a -> bool) -> 'a array -> bool
val exists : ('a -> bool) -> 'a array -> bool
val mem : 'a -> 'a array -> bool
val memq : 'a -> 'a array -> bool
val sort : ('a -> 'a -> int) -> 'a array -> unit
val stable_sort : ('a -> 'a -> int) -> 'a array -> unit
val fast_sort : ('a -> 'a -> int) -> 'a array -> unit
val to_seq : 'a array -> 'a Stdlib.Seq.t
val to_seqi : 'a array -> (int * 'a) Stdlib.Seq.t
val of_seq : 'a Stdlib.Seq.t -> 'a array

val unsafe_get : 'a array -> int -> 'a
val unsafe_set : 'a array -> int -> 'a -> unit

module Floatarray = Stdlib__array.Floatarray

type 'a t = 'a array: The type for arrays

val empty : 'a t: empty is the empty array, physically equal to ||.

val equal : 'a equal -> 'a t equal: equal eq a1 a2 is true if the lengths of a1 and a2 are the same and if their corresponding elements test equal, using eq.

val compare : 'a ord -> 'a t ord: compare cmp a1 a2 compares arrays a1 and a2 using the function comparison cmp.

val swap : 'a t -> int -> int -> unit

swap a i j swaps elements at indices i and j.

since: 1.4

val get : 'a t -> int -> 'a

get a n returns the element number n of array a. The first element has number 0. The last element has number length a - 1. You can also write a.(n) instead of get a n.

Raise Invalid_argument "index out of bounds" if n is outside the range 0 to (length a - 1).

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

set a n x modifies array a in place, replacing element number n with x. You can also write a.(n) <- x instead of set a n x.

Raise Invalid_argument "index out of bounds" if n is outside the range 0 to length a - 1.

val length : _ t -> int: length a returns the length (number of elements) of the given array a.

val fold : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a: fold f init a computes f (... (f (f init a.(0)) a.(1)) ...) a.(n-1), where n is the length of the array a.

val foldi : ('a -> int -> 'b -> 'a) -> 'a -> 'b t -> 'a: foldi f init a is just like fold, but it also passes in the index of each element as the second argument to the folded function f.

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

fold_while f init a folds left on array a until a stop condition via ('a, `Stop) is indicated by the accumulator.

since: 0.8

val fold_map : ('acc -> 'a -> 'acc * 'b) -> 'acc -> 'a t -> 'acc * 'b t

fold_map f init a is a fold_left-like function, but it also maps the array to another array.

since: 1.2, but only

since: 2.1 with labels

val scan_left : ('acc -> 'a -> 'acc) -> 'acc -> 'a t -> 'acc t

scan_left f init a returns the array [|init; f init x0; f (f init a.(0)) a.(1); …|] .

since: 1.2, but only

since: 2.1 with labels

val iter : ('a -> unit) -> 'a t -> unit: iter f a applies function f in turn to all elements of a. It is equivalent to f a.(0); f a.(1); ...; f a.(length a - 1); ().

val iteri : (int -> 'a -> unit) -> 'a t -> unit: iteri f a is like iter, but the function f is applied with the index of the element as first argument, and the element itself as second argument.

val blit : 'a t -> int -> 'a t -> int -> int -> unit

blit a1 o1 a2 o2 len copies len elements from array a1, starting at element number o1, to array a2, starting at element number o2. It works correctly even if a1 and a2 are the same array, and the source and destination chunks overlap.

Raise Invalid_argument "CCArray.blit" if o1 and len do not designate a valid subarray of a1, or if o2 and len do not designate a valid subarray of a2.

val reverse_in_place : 'a t -> unit: reverse_in_place a reverses the array a in place.

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

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

since: 1.0

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

sort_indices f a returns a new array b, with the same length as a, such that b.(i) is the index at which the i-th element of sorted f a appears in a. a is not modified.

In other words, map (fun i -> a.(i)) (sort_indices f a) = sorted f a. sort_indices yields the inverse permutation of sort_ranking.

since: 1.0

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

sort_ranking f a returns a new array b, with the same length as a, such that b.(i) is the index at which the i-th element of a appears in sorted f a. a is not modified.

In other words, map (fun i -> (sorted f a).(i)) (sort_ranking f a) = a. sort_ranking yields the inverse permutation of sort_indices.

In the absence of duplicate elements in a, we also have lookup_exn a.(i) (sorted a) = (sorted_ranking a).(i).

since: 1.0

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

find_map f a returns Some y if there is an element x such that f x = Some y. Otherwise returns None.

since: 1.3, but only

since: 2.1 with labels

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

find f a is an alias to find_map.

deprecated: since 1.3, use find_map instead. The version with labels is

deprecated: since 2.1, use find_map instead.

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

find_map_i f a is like find_map, but the index of the element is also passed to the predicate function f.

since: 1.3, but only

since: 2.1 with labels

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

findi f a is an alias to find_map_i.

since: 0.3.4

deprecated: since 1.3, use find_map instead. The version with labels is

deprecated: since 2.1, use find_map instead.

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

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

since: 0.3.4

val lookup : cmp:'a ord -> 'a -> 'a t -> int option

lookup ~cmp key a lookups the index of some key key in a sorted array a. Undefined behavior if the array a is not sorted wrt ~cmp. Complexity: O(log (n)) (dichotomic search).

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

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

lookup_exn ~cmp key a is like lookup, but

raises Not_found: if the key 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 key a finds the index of the object key in the array a, provided a 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 a (dichotomic search).

returns

`At i if cmp a.(i) key = 0 (for some i).
`All_lower if all elements of a are lower than key.
`All_bigger if all elements of a are bigger than key.
`Just_after i if a.(i) < key < a.(i+1).
`Empty if the array a 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: for_all f [|a1; ...; an|] is true if all elements of the array satisfy the predicate f. That is, it returns (f a1) && (f a2) && ... && (f an).

val for_all2 : ('a -> 'b -> bool) -> 'a t -> 'b t -> bool

for_all2 f [|a1; ...; an|] [|b1; ...; bn|] is true if each pair of elements ai bi satisfies the predicate f. That is, it returns (f a1 b1) && (f a2 b2) && ... && (f an bn).

raises Invalid_argument: if arrays have distinct lengths. Allow different types.

since: 0.20

val exists : ('a -> bool) -> 'a t -> bool: exists f [|a1; ...; an|] is true if at least one element of the array satisfies the predicate f. That is, it returns (f a1) || (f a2) || ... || (f an).

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

exists2 f [|a1; ...; an|] [|b1; ...; bn|] is true if any pair of elements ai bi satisfies the predicate f. That is, it returns (f a1 b1) || (f a2 b2) || ... || (f an bn).

raises Invalid_argument: if arrays have distinct lengths. Allow different types.

since: 0.20

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

fold2 f init a b fold on two arrays a and b stepwise. It computes f (... (f init a1 b1)...) an bn.

raises Invalid_argument: if a and b have distinct lengths.

since: 0.20

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

iter2 f a b iterates on the two arrays a and b stepwise. It is equivalent to f a0 b0; ...; f a.(length a - 1) b.(length b - 1); ().

raises Invalid_argument: if a and b have distinct lengths.

since: 0.20

val shuffle : 'a t -> unit: shuffle a randomly shuffles the array a, in place.

val shuffle_with : Stdlib.Random.State.t -> 'a t -> unit: shuffle_with rs a randomly shuffles the array a (like shuffle) but a specialized random state rs is used to control the random numbers being produced during shuffling (for reproducibility).

val random_choose : 'a t -> 'a random_gen

random_choose a rs randomly chooses an element of a.

raises Not_found: if the array/slice is empty.

val to_seq : 'a t -> 'a sequence: to_seq a returns a sequence of the elements of an array a. The input array a is shared with the sequence and modification of it will result in modification of the sequence.

val to_gen : 'a t -> 'a gen: to_gen a returns a gen of the elements of an array a.

val to_klist : 'a t -> 'a klist: to_klist returns a klist of the elements of an array a.

IO

val pp : ?⁠sep:string -> 'a printer -> 'a t printer: pp ~sep pp_item ppf a formats the array a on ppf. Each element is formatted with pp_item and elements are separated by sep (defaults to ", ").

val pp_i : ?⁠sep:string -> (int -> 'a printer) -> 'a t printer: pp_i ~sep pp_item ppf a prints the array a on ppf. The printing function pp_item is giving both index and element. Elements are separated by sep (defaults to ", ").

val map : ('a -> 'b) -> 'a t -> 'b t: map f a applies function f to all elements of a, and builds an array with the results returned by f: [| f a.(0); f a.(1); ...; f a.(length a - 1) |].

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

map2 f a b applies function f to all elements of a and b, and builds an array with the results returned by f: [| f a.(0) b.(0); ...; f a.(length a - 1) b.(length b - 1)|].

raises Invalid_argument: if a and b have distinct lengths.

since: 0.20

val rev : 'a t -> 'a t

rev a copies the array a and reverses it in place.

since: 0.20

val filter : ('a -> bool) -> 'a t -> 'a t: filter f a filters elements out of the array a. Only the elements satisfying the given predicate f will be kept.

val filter_map : ('a -> 'b option) -> 'a t -> 'b t: filter_map f [|a1; ...; an|] calls (f a1) ... (f an) and returns an array b consisting of all elements bi such as f ai = Some bi. When f returns None, the corresponding element of a is discarded.

val flat_map : ('a -> 'b t) -> 'a t -> 'b array: flat_map f a transforms each element of a into an array, then flattens.

val (>>=) : 'a t -> ('a -> 'b t) -> 'b t: a >>= f is the infix version of flat_map.

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

a >>| f is the infix version of map.

since: 0.8

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

a >|= f is the infix version of map.

since: 0.8

val except_idx : 'a t -> int -> 'a list: except_idx a i removes the element of a at given index i, and returns the list of the other elements.

val (--) : int -> int -> int t: x -- y creates an array containing integers in the range x .. y. Bounds included.

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

x --^ y creates an array containing integers in the range x .. y. Right bound excluded.

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

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_generic (module M) ~cmp a sorts the array a, without allocating (eats stack space though). Performance might be lower than Array.sort.

since: 0.14