edu.uky.rch.ept.xmlSegmentTree
Class AbstractSegmentTreeVisitor

java.lang.Object
  edu.uky.rch.ept.xmlSegmentTree.AbstractSegmentTreeVisitor

All Implemented Interfaces:

SegmentTreeVisitor

Direct Known Subclasses:

SegmentTree.OutputVisitor, SegmentTree.TransformedOutputVisitor

public abstract class AbstractSegmentTreeVisitor

extends Object

implements SegmentTreeVisitor

Abstract class for traversing a segment tree. Contains default implementations of all the methods of SegmentTreeVisitor except beginElement() and endElement(). These default implementations do nothing; preLeft() and preRight() always return true. getData() always returns null.

Constructor Summary

AbstractSegmentTreeVisitor()

Method Summary

abstract void	beginElement(Element e) Called for each Element beginning at this node.
abstract void	endElement(Element e) Called for each Element ending at this node.
void	enter(Position left, Position right) Called as a node of the segment tree is entered.
void	finished() Called just before SegmentTree.traverse() returns.
Object	getData() Retrieve data computed by the traversal.
void	postLeft(Position left, Position mid, Position right) Called just after recursing to the left subtree.
void	postRight(Position left, Position mid, Position right) Called just after recursing to the right subtree.
boolean	preLeft(Position left, Position mid, Position right) Called just before recursing to the left subtree.
boolean	preRight(Position left, Position mid, Position right) Called just before recursing to the right subtree.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSegmentTreeVisitor

public AbstractSegmentTreeVisitor()

Method Detail

enter

public void enter(Position left,
                  Position right)
           throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called as a node of the segment tree is entered.

Specified by:

enter in interface SegmentTreeVisitor

Parameters:

left - the lower bound for this node.

right - the upper bound for this node.

Throws:

TraversalException - to end the traversal

preLeft

public boolean preLeft(Position left,
                       Position mid,
                       Position right)
                throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called just before recursing to the left subtree.

Specified by:

preLeft in interface SegmentTreeVisitor

Parameters:

left - the left bound for this node and the left subtree

mid - the right bound for the left subtree

right - the right bound for this node

Returns:

true if we should continue down the left subtree, false otherwise

Throws:

TraversalException - to end the traversal

postLeft

public void postLeft(Position left,
                     Position mid,
                     Position right)
              throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called just after recursing to the left subtree.

Specified by:

postLeft in interface SegmentTreeVisitor

Parameters:

left - the left bound for this node and the left subtree

mid - the right bound for the left subtree

right - the right bound for this node

Throws:

TraversalException - to end the traversal

beginElement

public abstract void beginElement(Element e)
                           throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called for each Element beginning at this node. Called first for tagged elements, in decreasing order of length, then for string elements, in decreasing order of length.

Specified by:

beginElement in interface SegmentTreeVisitor

Parameters:

e - the element.

Throws:

TraversalException - to end the traversal

endElement

public abstract void endElement(Element e)
                         throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called for each Element ending at this node. Called first for string elements, in increasing order of length, then for tagged elements, in increasing order of length.

Specified by:

endElement in interface SegmentTreeVisitor

Parameters:

e - the element.

Throws:

TraversalException - to end the traversal

preRight

public boolean preRight(Position left,
                        Position mid,
                        Position right)
                 throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called just before recursing to the right subtree.

Specified by:

preRight in interface SegmentTreeVisitor

Parameters:

left - the left bound for this node

mid - the left bound for the right subtree

right - the right bound for this node and the right subtree

Returns:

true if we should continue down the right subtree, false otherwise

Throws:

TraversalException - to end the traversal

postRight

public void postRight(Position left,
                      Position mid,
                      Position right)
               throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called just after recursing to the right subtree.

Specified by:

postRight in interface SegmentTreeVisitor

Parameters:

left - the left bound for this node

mid - the left bound for the right subtree

right - the right bound for this node and the right subtree

Throws:

TraversalException - to end the traversal

finished

public void finished()
              throws TraversalException

Description copied from interface: SegmentTreeVisitor

Called just before SegmentTree.traverse() returns.

Specified by:

finished in interface SegmentTreeVisitor

Throws:

TraversalException - to end the traversal

getData

public Object getData()

Description copied from interface: SegmentTreeVisitor

Retrieve data computed by the traversal. This method is not called by SegmentTree.traverse().

Specified by:

getData in interface SegmentTreeVisitor

Returns:

data computed during the traversal, possibly null.