Comparable.php

<?php

/*
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the MIT license. For more information, see
 * <http://www.doctrine-project.org>.
 */
namespace Doctrine\Common;


/**
 * Comparable interface that allows to compare two value objects to each other for similarity.
 *
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.com
 * @since       2.2
 * @author      Benjamin Eberlei <kontakt@beberlei.de>
 * @author      Guilherme Blanco <guilhermeblanco@hotmail.com>
 */
interface Comparable {

  /**
   * Compare the current object to the passed $other.
   *
   * Returns 0 if they are semantically equal, 1 if the other object
   * is less than the current one, or -1 if its more than the current one.
   *
   * This method should not check for identity using ===, only for semantical equality for example
   * when two different DateTime instances point to the exact same Date + TZ.
   *
   * @param mixed $other
   *
   * @return int
   */
  public function compareTo($other);

}