Double Dispatch Example

• DirectoryNode node = new DirectoryNode(new File(".."));
  node.accept(new PrintVisitor());
  
• node is a DirectoryNode
• Polymorphism: node.accept calls DirectoryNode.accept
• That method calls v.visitDirectoryNode
• v is a PrintVisitor
• Polymorphism: calls PrintVisitor.visitDirectoryNode
• Two polymorphic calls determine
• • node type
  • visitor type