Every node has one and only one primary node type.
This data includes the node type, title, teaser, body, creator, and creation time.
The matched function is like our prior visitor functions but takes a node type to search for at the beginning.
Of course, not all node types have all these properties.
The everything-is-a-node abstraction loses some value because of the number of node types that exist, and because of the lack of uniformity present in their access methods.
The default is displayed in Figure 3; it gives you the ability to fold subelements, edit both bodies and attributes, and differentiate node types.
