as reported by Eric C. Newton.
the order during a postorder walk, because it is called _after_
the walk has occurred.) The ASTVisitor modifies the visitor
argument by adding a visit method to the visitor; this method can
- be used to visit a particular child node. If the visitor method
- returns a true value, the ASTVisitor will not traverse the child
- nodes.
+ be used to visit a particular child node.
XXX The interface for controlling the preorder walk needs to be
re-considered. The current interface is convenient for visitors