Module Array
module Array:sig
..end
type'a
t ='a array
An alias for the type of arrays.
Array operations.
val length : 'a array -> int
Return the length (number of elements) of the given array.
val get : 'a array -> int -> 'a
Array.get a n
returns the element number n
of array a
.
The first element has number 0.
The last element has number Array.length a - 1
.
You can also write a.(n)
instead of Array.get a n
.
Raise Invalid_argument
if n
is outside the range 0 to (Array.length a - 1)
.
val set : 'a array -> int -> 'a -> unit
Array.set a n x
modifies array a
in place, replacing
element number n
with x
.
You can also write a.(n) <- x
instead of Array.set a n x
.
Raise Invalid_argument
if n
is outside the range 0 to Array.length a - 1
.
val make : int -> 'a -> 'a array
Array.make n x
returns a fresh array of length n
,
initialized with x
.
All the elements of this new array are initially
physically equal to x
(in the sense of the ==
predicate).
Consequently, if x
is mutable, it is shared among all elements
of the array, and modifying x
through one of the array entries
will modify all other entries at the same time.
Raise Invalid_argument
if n < 0
or n > Sys.max_array_length
.
If the value of x
is a floating-point number, then the maximum
size is only Sys.max_array_length / 2
.
val create : int -> 'a -> 'a array
val create_float : int -> float array
Array.create_float n
returns a fresh float array of length n
,
with uninitialized data.
- Since 4.03
val make_float : int -> float array
val init : int -> (int -> 'a) -> 'a array
Array.init n f
returns a fresh array of length n
,
with element number i
initialized to the result of f i
.
In other terms, Array.init n f
tabulates the results of f
applied to the integers 0
to n-1
.
Raise Invalid_argument
if n < 0
or n > Sys.max_array_length
.
If the return type of f
is float
, then the maximum
size is only Sys.max_array_length / 2
.
val make_matrix : int -> int -> 'a -> 'a array array
Array.make_matrix dimx dimy e
returns a two-dimensional array
(an array of arrays) with first dimension dimx
and
second dimension dimy
. All the elements of this new matrix
are initially physically equal to e
.
The element (x,y
) of a matrix m
is accessed
with the notation m.(x).(y)
.
Raise Invalid_argument
if dimx
or dimy
is negative or
greater than Sys.max_array_length
.
If the value of e
is a floating-point number, then the maximum
size is only Sys.max_array_length / 2
.
val create_matrix : int -> int -> 'a -> 'a array array
val append : 'a array -> 'a array -> 'a array
Array.append v1 v2
returns a fresh array containing the
concatenation of the arrays v1
and v2
.
Raise Invalid_argument
if
Array.length v1 + Array.length v2 > Sys.max_array_length
.
val concat : 'a array list -> 'a array
Same as Array.append
, but concatenates a list of arrays.
val sub : 'a array -> int -> int -> 'a array
Array.sub a start len
returns a fresh array of length len
,
containing the elements number start
to start + len - 1
of array a
.
Raise Invalid_argument
if start
and len
do not
designate a valid subarray of a
; that is, if
start < 0
, or len < 0
, or start + len > Array.length a
.
val copy : 'a array -> 'a array
Array.copy a
returns a copy of a
, that is, a fresh array
containing the same elements as a
.
val fill : 'a array -> int -> int -> 'a -> unit
Array.fill a ofs len x
modifies the array a
in place,
storing x
in elements number ofs
to ofs + len - 1
.
Raise Invalid_argument
if ofs
and len
do not
designate a valid subarray of a
.
val blit : 'a array -> int -> 'a array -> int -> int -> unit
Array.blit v1 o1 v2 o2 len
copies len
elements
from array v1
, starting at element number o1
, to array v2
,
starting at element number o2
. It works correctly even if
v1
and v2
are the same array, and the source and
destination chunks overlap.
Raise Invalid_argument
if o1
and len
do not
designate a valid subarray of v1
, or if o2
and len
do not
designate a valid subarray of v2
.
val to_list : 'a array -> 'a list
Array.to_list a
returns the list of all the elements of a
.
val of_list : 'a list -> 'a array
Array.of_list l
returns a fresh array containing the elements
of l
.
Raise Invalid_argument
if the length of l
is greater than
Sys.max_array_length
.
Iterators
val iter : ('a -> unit) -> 'a array -> unit
Array.iter f a
applies function f
in turn to all
the elements of a
. It is equivalent to
f a.(0); f a.(1); ...; f a.(Array.length a - 1); ()
.
val iteri : (int -> 'a -> unit) -> 'a array -> unit
Same as Array.iter
, but the
function is applied with the index of the element as first argument,
and the element itself as second argument.
val map : ('a -> 'b) -> 'a array -> 'b array
Array.map f a
applies function f
to all the elements of a
,
and builds an array with the results returned by f
:
[| f a.(0); f a.(1); ...; f a.(Array.length a - 1) |]
.
val mapi : (int -> 'a -> 'b) -> 'a array -> 'b array
Same as Array.map
, but the
function is applied to the index of the element as first argument,
and the element itself as second argument.
val fold_left : ('a -> 'b -> 'a) -> 'a -> 'b array -> 'a
Array.fold_left f x a
computes
f (... (f (f x a.(0)) a.(1)) ...) a.(n-1)
,
where n
is the length of the array a
.
val fold_right : ('b -> 'a -> 'a) -> 'b array -> 'a -> 'a
Array.fold_right f a x
computes
f a.(0) (f a.(1) ( ... (f a.(n-1) x) ...))
,
where n
is the length of the array a
.
Iterators on two arrays
val iter2 : ('a -> 'b -> unit) -> 'a array -> 'b array -> unit
Array.iter2 f a b
applies function f
to all the elements of a
and b
.
Raise Invalid_argument
if the arrays are not the same size.
- Since 4.03.0
val map2 : ('a -> 'b -> 'c) -> 'a array -> 'b array -> 'c array
Array.map2 f a b
applies function f
to all the elements of a
and b
, and builds an array with the results returned by f
:
[| f a.(0) b.(0); ...; f a.(Array.length a - 1) b.(Array.length b - 1)|]
.
Raise Invalid_argument
if the arrays are not the same size.
- Since 4.03.0
Array scanning
val for_all : ('a -> bool) -> 'a array -> bool
Array.for_all p [|a1; ...; an|]
checks if all elements of the array
satisfy the predicate p
. That is, it returns
(p a1) && (p a2) && ... && (p an)
.
- Since 4.03.0
val exists : ('a -> bool) -> 'a array -> bool
Array.exists p [|a1; ...; an|]
checks if at least one element of
the array satisfies the predicate p
. That is, it returns
(p a1) || (p a2) || ... || (p an)
.
- Since 4.03.0
val mem : 'a -> 'a array -> bool
mem a l
is true if and only if a
is structurally equal
to an element of l
(i.e. there is an x
in l
such that
compare a x = 0
).
- Since 4.03.0
val memq : 'a -> 'a array -> bool
Same as Array.mem
, but uses physical equality instead of structural
equality to compare elements.
- Since 4.03.0
Sorting
val sort : ('a -> 'a -> int) -> 'a array -> unit
Sort an array in increasing order according to a comparison
function. The comparison function must return 0 if its arguments
compare as equal, a positive integer if the first is greater,
and a negative integer if the first is smaller (see below for a
complete specification). For example, compare
is
a suitable comparison function. After calling Array.sort
, the
array is sorted in place in increasing order.
Array.sort
is guaranteed to run in constant heap space
and (at most) logarithmic stack space.
The current implementation uses Heap Sort. It runs in constant stack space.
Specification of the comparison function:
Let a
be the array and cmp
the comparison function. The following
must be true for all x
, y
, z
in a
:
-
cmp x y
> 0 if and only ifcmp y x
< 0 - if
cmp x y
>= 0 andcmp y z
>= 0 thencmp x z
>= 0
When Array.sort
returns, a
contains the same elements as before,
reordered in such a way that for all i and j valid indices of a
:
-
cmp a.(i) a.(j)
>= 0 if and only if i >= j
val stable_sort : ('a -> 'a -> int) -> 'a array -> unit
Same as Array.sort
, but the sorting algorithm is stable (i.e.
elements that compare equal are kept in their original order) and
not guaranteed to run in constant heap space.
The current implementation uses Merge Sort. It uses a temporary
array of length n/2
, where n
is the length of the array.
It is usually faster than the current implementation of Array.sort
.
val fast_sort : ('a -> 'a -> int) -> 'a array -> unit
Same as Array.sort
or Array.stable_sort
, whichever is faster
on typical input.
Iterators
val to_seq : 'a array -> 'a Seq.t
Iterate on the array, in increasing order. Modifications of the array during iteration will be reflected in the iterator.
- Since 4.07
val to_seqi : 'a array -> (int * 'a) Seq.t
Iterate on the array, in increasing order, yielding indices along elements. Modifications of the array during iteration will be reflected in the iterator.
- Since 4.07
val of_seq : 'a Seq.t -> 'a array
Create an array from the generator
- Since 4.07