Any node has exactly one attribute of type 1. That attribute is a cardinal stored as a little endian byte vector. The attribute is 0 (i.e. the empty byte vector) if the node has no left, right, or url attributes. Otherwise, the attribute is 1 (i.e. a byte vector of length 1 whose sole byte has value 1).
Attributes of type 1 are referred to as 'node type' attributes. A node whose node type attribute is empty is referred to as a 'leaf' node, and other nodes are referred to as 'proper' nodes. Proper nodes must have a left and a right attribute but needs not have url attributes.
Copyright © 2009 Klaus Grue, GRD-2009-10-01