PriorityArray.php

<?php

/**
 * Priority Array
 *
 * @since 1.3
 */
class PriorityArray implements \IteratorAggregate, \ArrayAccess, \Serializable, \Countable {

	/*** Properties ***********************************************************/

	/**
	 * Elements List
	 *
	 * @var array
	 * @since 1.3
	 */
	protected $e6s = array();

	/**
	 * Priorities List.
	 *
	 * @var array
	 * @since 1.3
	 */
	protected $p8s = array();

	/**
	 * Is Sorted? (Flag)
	 *
	 * @var bool
	 * @since 1.3
	 */
	private $is_sorted = false;


	/*** Methods **************************************************************/

	/**
	 * @return void
	 * @since 1.3
	 */
	public function offsetSet( $index, $value, $priority = 10 ) {

		$this->p8s[ $index ] = (int) $priority;
		$this->e6s[ $index ] = $value;
		$this->is_sorted = false;

	}

	/**
	 * @return bool
	 * @since 1.3
	 */
	public function offsetExists( $index ) {
		return isset( $this->e6s[ $index ] );
	}

	/**
	 * @return void
	 * @since 1.3
	 */
	public function offsetUnset( $index ) {

		unset( $this->p8s[ $index ] );
		unset( $this->e6s[ $index ] );

	}

	/**
	 * @return mixed
	 * @since 1.3
	 */
	public function offsetGet( $index ) {

		if ( $this->offsetExists( $index ) ) {
			return $this->e6s[ $index ];
		}

	}

	/**
	 * @return ArrayIterator
	 * @since 1.3
	 */
	public function getIterator() {

		$this->maybeSort(); // Sort the array.
		return new \ArrayIterator( $this->e6s );

	}

	/**
	 * @return void
	 * @since 1.3
	 */
	public function unserialize( $data ) {
		$this->e6s = unserialize( $data );
	}

	/**
	 * @return string
	 * @since 1.3
	 */
	public function serialize() {
		return serialize( $this->e6s );
	}

	/**
	 * @return bool
	 * @since 1.3
	 */
	public function maybeSort() {

		if ( ! $this->is_sorted ) {

			$p8s = (array) $this->p8s;

			$this->is_sorted = uksort( $this->e6s,

				function( $a, $b ) use ( &$p8s ) {

					$p1 = (int) $p8s[ $a ];
					$p2 = (int) $p8s[ $b ];

					if ( $p1 === $p2 ) {
						return 0;
					}

					return ( $p1 < $p2 ) ? +1 : -1;

				}

			);

		}

		return $this->is_sorted;

	}

	/**
	 * @return int
	 * @since 1.3
	 */
	public function count() {
		return count( $this->e6s );
	}

}