<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * 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 LGPL. For more information, see
 * <http://www.phpdoctrine.org>.
 */

namespace Doctrine\ORM\Query\Parser;

/**
 * FromClause ::= "FROM" IdentificationVariableDeclaration {"," IdentificationVariableDeclaration}
 *
 * @author      Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author      Janne Vanhala <jpvanhal@cc.hut.fi>
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        http://www.phpdoctrine.org
 * @since       1.0
 * @version     $Revision$
 */
class FromClause extends \Doctrine\ORM\Query\ParserRule
{
    protected $_AST = null;
    
    public function syntax()
    {
        // FromClause ::= "FROM" IdentificationVariableDeclaration {"," IdentificationVariableDeclaration}
        $this->_AST = $this->AST('FromClause');
        
        $this->_parser->match(\Doctrine\ORM\Query\Token::T_FROM);

        $this->_AST->addIdentificationVariableDeclaration(
            $this->parse('IdentificationVariableDeclaration')
        );

        while ($this->_isNextToken(',')) {
            $this->_parser->match(',');

            $this->_AST->addIdentificationVariableDeclaration(
                $this->parse('IdentificationVariableDeclaration')
            );
        }
        
        // Return AST node
        return $this->_AST;
    }
}