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/**
 * This file is part of the Nette Framework (https://nette.org)
 * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 */

declare(strict_types=1);

namespace Nette\Utils;

use Nette;


/**
 * Provides the base class for a generic list (items can be accessed by index).
 * @template T
 * @implements \IteratorAggregate&lt;int, T&gt;
 * @implements \ArrayAccess&lt;int, T&gt;
 */
class ArrayList implements \ArrayAccess, \Countable, \IteratorAggregate
{
	use Nette\SmartObject;

	/** @var mixed[] */
	private $list = [];


	/**
	 * Transforms array to ArrayList.
	 * @param  list&lt;T&gt;  $array
	 * @return static
	 */
	public static function from(array $array)
	{
		if (!Arrays::isList($array)) {
			throw new Nette\InvalidArgumentException('Array is not valid list.');
		}

		$obj = new static;
		$obj-&gt;list = $array;
		return $obj;
	}


	/**
	 * Returns an iterator over all items.
	 * @return \ArrayIterator&lt;int, T&gt;
	 */
	public function getIterator(): \ArrayIterator
	{
		return new \ArrayIterator($this-&gt;list);
	}


	/**
	 * Returns items count.
	 */
	public function count(): int
	{
		return count($this-&gt;list);
	}


	/**
	 * Replaces or appends a item.
	 * @param  int|null  $index
	 * @param  T  $value
	 * @throws Nette\OutOfRangeException
	 */
	public function offsetSet($index, $value): void
	{
		if ($index === null) {
			$this-&gt;list[] = $value;

		} elseif (!is_int($index) || $index &lt; 0 || $index &gt;= count($this-&gt;list)) {
			throw new Nette\OutOfRangeException('Offset invalid or out of range');

		} else {
			$this-&gt;list[$index] = $value;
		}
	}


	/**
	 * Returns a item.
	 * @param  int  $index
	 * @return T
	 * @throws Nette\OutOfRangeException
	 */
	#[\ReturnTypeWillChange]
	public function offsetGet($index)
	{
		if (!is_int($index) || $index &lt; 0 || $index &gt;= count($this-&gt;list)) {
			throw new Nette\OutOfRangeException('Offset invalid or out of range');
		}

		return $this-&gt;list[$index];
	}


	/**
	 * Determines whether a item exists.
	 * @param  int  $index
	 */
	public function offsetExists($index): bool
	{
		return is_int($index) &amp;&amp; $index &gt;= 0 &amp;&amp; $index &lt; count($this-&gt;list);
	}


	/**
	 * Removes the element at the specified position in this list.
	 * @param  int  $index
	 * @throws Nette\OutOfRangeException
	 */
	public function offsetUnset($index): void
	{
		if (!is_int($index) || $index &lt; 0 || $index &gt;= count($this-&gt;list)) {
			throw new Nette\OutOfRangeException('Offset invalid or out of range');
		}

		array_splice($this-&gt;list, $index, 1);
	}


	/**
	 * Prepends a item.
	 * @param  T  $value
	 */
	public function prepend($value): void
	{
		$first = array_slice($this-&gt;list, 0, 1);
		$this-&gt;offsetSet(0, $value);
		array_splice($this-&gt;list, 1, 0, $first);
	}
}
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