diff -r 6d109e3804ac -r 9a001a04b634 Twig-1.3.0/lib/Twig/NodeVisitorInterface.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Twig-1.3.0/lib/Twig/NodeVisitorInterface.php	Tue Oct 25 23:56:28 2011 +0200
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2009 Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Twig_NodeVisitorInterface is the interface the all node visitor classes must implement.
+ *
+ * @package    twig
+ * @author     Fabien Potencier <fabien@symfony.com>
+ */
+interface Twig_NodeVisitorInterface
+{
+    /**
+     * Called before child nodes are visited.
+     *
+     * @param Twig_NodeInterface $node The node to visit
+     * @param Twig_Environment   $env  The Twig environment instance
+     *
+     * @param Twig_NodeInterface The modified node
+     */
+    function enterNode(Twig_NodeInterface $node, Twig_Environment $env);
+
+    /**
+     * Called after child nodes are visited.
+     *
+     * @param Twig_NodeInterface $node The node to visit
+     * @param Twig_Environment   $env  The Twig environment instance
+     *
+     * @param Twig_NodeInterface The modified node
+     */
+    function leaveNode(Twig_NodeInterface $node, Twig_Environment $env);
+
+    /**
+     * Returns the priority for this visitor.
+     *
+     * Priority should be between -10 and 10 (0 is the default).
+     *
+     * @return integer The priority level
+     */
+    function getPriority();
+}