1: <?php
 2: namespace Pharborist;
 3: 
 4: /**
 5:  * A node tree visitor.
 6:  */
 7: interface VisitorInterface {
 8:   /**
 9:    * Called when visiting node.
10:    *
11:    * @param Node $node
12:    *   Node being visited.
13:    */
14:   public function visit(Node $node);
15: 
16:   /**
17:    * Called when completed visiting a parent node.
18:    *
19:    * @param ParentNode $node
20:    *   Parent node being visited.
21:    */
22:   public function visitEnd(ParentNode $node);
23: }
24: