dumbo/vendor/doctrine/common/lib/Doctrine/Common/Comparable.php

<?php
/*
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 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * 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.
 *
 * @link   www.doctrine-project.org
 * @since  2.2
 * @author Benjamin Eberlei <kontakt@beberlei.de>
 * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
 */
interface Comparable
{
    /**
     * Compares 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);
}