56 lines
1.8 KiB
PHP
56 lines
1.8 KiB
PHP
<?php
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/*
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* $Id$
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This software consists of voluntary contributions made by many individuals
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* and is licensed under the LGPL. For more information, see
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* <http://www.phpdoctrine.org>.
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*/
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/**
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* Doctrine_Null
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*
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* Simple empty class representing a null value.
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* Used for extra fast null value testing with isset() rather than array_key_exists().
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*
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* @package Doctrine
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* @subpackage Null
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* @license http://www.opensource.org/licenses/lgpl-license.php LGPL
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* @link www.phpdoctrine.org
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* @since 1.0
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* @version $Revision$
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* @author Konsta Vesterinen <kvesteri@cc.hut.fi>
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*/
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// static initializer
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Doctrine_Null::$INSTANCE = new Doctrine_Null();
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final class Doctrine_Null
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{
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public static $INSTANCE;
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public function __construct() {}
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public static function getInstance()
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{
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return self::$INSTANCE;
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}
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public function exists()
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{
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return false;
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}
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public function __toString()
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{
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return '';
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}
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} |