<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 3.0.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\Database;
/**
* An interface used by Expression objects.
*/
interface ExpressionInterface
{
/**
* Converts the Node into a SQL string fragment.
*
* @param \Cake\Database\ValueBinder $generator Placeholder generator object
* @return string
*/
public function sql(ValueBinder $generator);
/**
* Iterates over each part of the expression recursively for every
* level of the expressions tree and executes the $visitor callable
* passing as first parameter the instance of the expression currently
* being iterated.
*
* @param callable $visitor The callable to apply to all nodes.
* @return void
*/
public function traverse(callable $visitor);
}