com.rabbitmq.jms.parse

Class ParseTreeTraverser

java.lang.Object

com.rabbitmq.jms.parse.ParseTreeTraverser

public abstract class ParseTreeTraverser
extends java.lang.Object

This traverser class encapsulates two methods of traversing a tree, calling a Visitor for each subtree of a ParseTree<Node>.

Each subtree can be visited in ‘pre-order’ as well asO in ‘post-order’. ‘Pre-order’ visits each subtree before any of its child subtrees, and ‘post-order’ visits each subtree after visiting its child subtrees.

traverse(ParseTree, Visitor) visits each subtree twice: combining ‘pre-order’ and ‘post-order’ traversal in one pass.

The Visitor contract returns a boolean flag from its visit methods which these traversal algorithms interpret as immediate abort: no further visits will be made after the first returns false. Each traversal method returns true if all the tree is visited, and false if any visit aborted.

Method Summary

Modifier and Type	Method and Description
static <Node> boolean	traverse(ParseTree<Node> tree, Visitor<Node> visitor) Visits each subtree in both ‘pre-order’ and ‘post-order’, in one pass.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

traverse

public static <Node> boolean traverse(ParseTree<Node> tree,
                                      Visitor<Node> visitor)

Visits each subtree in both ‘pre-order’ and ‘post-order’, in one pass. Each subtree is visited before (by calling Visitor.visitBefore(Object, Object[])) and after (by calling Visitor.visitAfter(Object, Object[])) all of its child subtrees are visited.

Parameters:

tree - the tree all of whose subtrees are to be visited

visitor - the Visitor whose Visitor.visitBefore(Object, Object[]) and Visitor.visitAfter(Object, Object[]) methods are passed each subtree’s node and child nodes.

Returns:

true if the traversal completed, false if it was aborted prematurely