interface Twig_NodeVisitorInterface

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
   *
   * @return 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
   *
   * @return 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();

}