<?php
/*
 * 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.doctrine-project.org>.
 */
 
namespace Doctrine\ORM\Query\AST;

/**
 * AssociationPathExpression ::= CollectionValuedPathExpression | SingleValuedAssociationPathExpression
 * SingleValuedPathExpression ::= StateFieldPathExpression | SingleValuedAssociationPathExpression
 * StateFieldPathExpression ::= SimpleStateFieldPathExpression | SimpleStateFieldAssociationPathExpression
 * SingleValuedAssociationPathExpression ::= IdentificationVariable "." SingleValuedAssociationField
 * CollectionValuedPathExpression ::= IdentificationVariable "." CollectionValuedAssociationField
 * StateField ::= {EmbeddedClassStateField "."}* SimpleStateField
 * SimpleStateFieldPathExpression ::= IdentificationVariable "." StateField
 * 
 * @since   2.0
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Jonathan Wage <jonwage@gmail.com>
 * @author  Roman Borschel <roman@code-factory.org>
 */
class PathExpression extends Node
{
    const TYPE_COLLECTION_VALUED_ASSOCIATION = 2;
    const TYPE_SINGLE_VALUED_ASSOCIATION = 4;
    const TYPE_STATE_FIELD = 8;
    
    public $type;
    public $expectedType;
    public $identificationVariable;
    public $field;
    
    public function __construct($expectedType, $identificationVariable, $field = null)
    {
        $this->expectedType = $expectedType;
        $this->identificationVariable = $identificationVariable;
        $this->field = $field;
    }
    
    public function dispatch($walker)
    {
        return $walker->walkPathExpression($this);
    }
}
