Funkcije iteratorja
*******************

.[perex]{data-version:4.0.4}
[api:Nette\Utils\Iterables] je statični razred s funkcijami za delo z iteratorji. Njegova ustreznica za polja je [Nette\Utils\Arrays |arrays].


Namestitev:

```shell
composer require nette/utils
```

Vsi primeri predvidevajo vzpostavitev vzdevka:

```php
use Nette\Utils\Iterables;
```


contains(iterable $iterable, $value): bool .[method]
----------------------------------------------------

Preizkusi prisotnost vrednosti v iteratorju. Uporablja strogo primerjavo (`===`).

```php
Iterables::contains(new ArrayIterator([1, 2, 3]), 1);    // true
Iterables::contains(new ArrayIterator([1, 2, 3]), '1');  // false
```


containsKey(iterable $iterable, $value): bool .[method]
-------------------------------------------------------

Preizkusi prisotnost ključa v iteratorju. Uporablja strogo primerjavo (`===`).

```php
Iterables::containsKey(new ArrayIterator([1, 2, 3]), 0);  // true
Iterables::containsKey(new ArrayIterator([1, 2, 3]), 4);  // false
```


every(iterable $iterable, callable $predicate): bool .[method]
--------------------------------------------------------------

Preizkusi, ali vsi elementi iteratorja prestanejo test, implementiran v `$predicate` s podpisom `function ($value, $key, iterable $iterable): bool`.

```php
$iterator = new ArrayIterator([1, 30, 39, 29, 10, 13]);
$isBelowThreshold = fn($value) => $value < 40;
$res = Iterables::every($iterator, $isBelowThreshold); // true
```

Glej [some( |#some()]).


filter(iterable $iterable, callable $predicate): Generator .[method]
--------------------------------------------------------------------

Iterator, ki filtrira elemente v skladu s predikatom. Predikat ima podpis `function ($value, $key, iterable $iterable): bool`. Ohranja prvotne ključe.

```php
$iterator = new ArrayIterator([1, 2, 3]);
$iterator = Iterables::filter($iterator, fn($v) => $v < 3);
// 1, 2
```


first(iterable $iterable, ?callable $predicate=null, ?callable $else=null): mixed .[method]
-------------------------------------------------------------------------------------------

Vrne prvi element (ki ustreza predikatu, če je določen). Če takega elementa ni, vrne rezultat klica `$else` ali nič.
Parameter `$predicate` ima podpis `function ($value, $key, iterable $iterable): bool`.

```php
Iterables::first(new ArrayIterator([1, 2, 3]));                   // 1
Iterables::first(new ArrayIterator([1, 2, 3]), fn($v) => $v > 2); // 3
Iterables::first(new ArrayIterator([]));                          // null
Iterables::first(new ArrayIterator([]), else: fn() => false);     // false
```


firstKey(iterable $iterable, ?callable $predicate=null, ?callable $else=null): mixed .[method]
----------------------------------------------------------------------------------------------

Vrne ključ prvega elementa (ki ustreza predikatu, če je določen). Če takega elementa ni, vrne rezultat klica `$else` ali nič. Predikat ima podpis `function ($value, $key, iterable $iterable): bool`.

```php
Iterables::firstKey(new ArrayIterator([1, 2, 3]));                   // 0
Iterables::firstKey(new ArrayIterator([1, 2, 3]), fn($v) => $v > 2); // 2
Iterables::firstKey(new ArrayIterator(['a' => 1, 'b' => 2]));        // 'a'
Iterables::firstKey(new ArrayIterator([]));                          // null
```


map(iterable $iterable, callable $transformer): array .[method]
---------------------------------------------------------------

Iterator, ki preoblikuje vrednosti s klicem `$transformer`. Ima podpis `function ($value, $key, iterable $iterable): bool`. Ohrani prvotne ključe.

```php
$iterator = new ArrayIterator([1, 2, 3]);
$iterator = Iterables::map($iterator, fn($v) => $v * 2);
// 2, 4, 6
```


some(iterable $iterable, callable $predicate): bool .[method]
-------------------------------------------------------------

Preizkusi, ali vsaj en element iteratorja izpolnjuje test, implementiran v `$predicate` s podpisom `function ($value, $key, iterable $iterable): bool`.

```php
$iterator = new ArrayIterator([1, 30, 39, 29, 10, 13]);
$isEven = fn($value) => $value % 2 === 0;
$res = Iterables::some($iterator, $isEven); // true
```

Glej [every( |#every()]).