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doc/containers/CCArrayLabels/index.html
Module CCArrayLabels
Source
Array utils
Fast internal iterator.
Arrays
include module type of CCShimsArrayLabels_
include module type of ArrayLabels with module Floatarray = Array.Floatarray
An alias for the type of arrays.
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.
create_float n
returns a fresh float array of length n
, with uninitialized data.
init n ~f
returns a fresh array of length n
, with element number i
initialized to the result of f i
. In other terms, init n ~f
tabulates the results of f
applied to the integers 0
to n-1
.
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)
.
append v1 v2
returns a fresh array containing the concatenation of the arrays v1
and v2
.
sub a ~pos ~len
returns a fresh array of length len
, containing the elements number pos
to pos + len - 1
of array a
.
copy a
returns a copy of a
, that is, a fresh array containing the same elements as a
.
fill a ~pos ~len x
modifies the array a
in place, storing x
in elements number pos
to pos + len - 1
.
to_list a
returns the list of all the elements of a
.
of_list l
returns a fresh array containing the elements of l
.
Iterators
Same as map
, but the function is applied to the index of the element as first argument, and the element itself as second argument.
fold_left ~f ~init a
computes f (... (f (f init a.(0)) a.(1)) ...) a.(n-1)
, where n
is the length of the array a
.
fold_right ~f a ~init
computes f a.(0) (f a.(1) ( ... (f a.(n-1) init) ...))
, where n
is the length of the array a
.
Iterators on two arrays
Array scanning
mem a ~set
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
).
Same as mem
, but uses physical equality instead of structural equality to compare list elements.
find_opt ~f a
returns the first element of the array a
that satisfies the predicate f
, or None
if there is no value that satisfies f
in the array a
.
Arrays of pairs
split [|(a1,b1); ...; (an,bn)|]
is ([|a1; ...; an|], [|b1; ...; bn|])
.
combine [|a1; ...; an|] [|b1; ...; bn|]
is [|(a1,b1); ...; (an,bn)|]
. Raise Invalid_argument
if the two arrays have different lengths.
Sorting
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, Stdlib.compare
is a suitable comparison function. After calling sort
, the array is sorted in place in increasing order. 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 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
Same as 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 sort
.
Same as sort
or stable_sort
, whichever is faster on typical input.
Arrays and Sequences
Iterate on the array, in increasing order, yielding indices along elements. Modifications of the array during iteration will be reflected in the sequence.
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
.
compare cmp a1 a2
compares arrays a1
and a2
using the function comparison cmp
.
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)
.
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
.
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
.
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
.
fold_while ~f ~init a
folds left on array a
until a stop condition via ('a, `Stop)
is indicated by the accumulator.
fold_map ~f ~init a
is a fold_left
-like function, but it also maps the array to another array.
scan_left ~f ~init a
returns the array [|~init; ~f ~init x0; ~f (~f ~init a.(0)) a.(1); …|]
.
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); ()
.
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.
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
.
sorted ~f a
makes a copy of a
and sorts it with ~f
.
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
.
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)
.
find_map ~f a
returns Some y
if there is an element x
such that ~f x = Some y
. Otherwise returns None
.
find_map_i ~f a
is like find_map
, but the index of the element is also passed to the predicate function ~f
.
find_idx ~f a
returns Some (i,x)
where x
is the i
-th element of a
, and ~f x
holds. Otherwise returns None
.
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).
lookup_exn ~cmp ~key a
is like lookup
, but
val bsearch :
cmp:('a -> 'a -> int) ->
key:'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).
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)
.
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)
.
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)
.
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)
.
fold2 ~f ~init a b
fold on two arrays a
and b
stepwise. It computes ~f (... (~f ~init a1 b1)...) an bn
.
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); ()
.
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).
random_choose a rs
randomly chooses an element of a
.
to_string ~sep item_to_string a
print a
to a string using sep
as a separator between elements of a
.
to_iter a
returns an iter
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 iterator.
to_std_seq a
returns a Seq.t
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.
IO
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 ", ").
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 ", ").
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) |]
.
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)|]
.
filter ~f a
filters elements out of the array a
. Only the elements satisfying the given predicate ~f
will be kept.
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.
All combinaisons of tuples from the two arrays are passed to the function
flat_map ~f a
transforms each element of a
into an array, then flattens.
except_idx a i
removes the element of a
at given index i
, and returns the list of the other elements.
x -- y
creates an array containing integers in the range x .. y
. Bounds included.
x --^ y
creates an array containing integers in the range x .. y
. Right bound excluded.
Generic Functions
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
.
Infix Operators
It is convenient to openCCArray.Infix
to access the infix operators without cluttering the scope too much.
Let operators on OCaml >= 4.08.0, nothing otherwise