com.tangosol.util
Class Tree.Crawler

java.lang.Object
  com.tangosol.util.Tree.Crawler

All Implemented Interfaces:

Cloneable, Enumeration

Enclosing class:

Tree

protected static class Tree.Crawler
extends Object
implements Enumeration, Cloneable

A red/black tree node iterator. Simple concept:

1. The node crawler knows what node it is on.
2. The node crawler knows how it got there (from above, below left, from itself (it just returned this nodes value), or from below right)
3. Using 1 and 2, the node crawler knows where to go next.
4. The result of 3 is that at the next node (see 1) the crawler knows how it got there (see 2).

The methods of this local class are not synchronized; the enclosing class is responsible for synchronization.

Author:

Cameron Purdy

Field Summary

protected static int	ABOVE
protected Tree.Node	current
protected int	fromdir
protected static int	LEFT
protected static Tree.Node	NIL NIL is the sentinal Node that is used instead of null, simplifying the implementation of the red/black tree.
protected static int	RIGHT
protected static int	SITTING

Constructor Summary

	Tree.Crawler(Tree.Node head) Crawler constructor.
protected	Tree.Crawler(Tree.Node head, int fromdir) Crawler constructor.

Method Summary

Object	clone() Make a shallow copy of the node crawler.
boolean	hasMoreElements() Tests if this enumeration contains more elements.
Object	nextElement() Returns the next element of this enumeration.
String	toString() Provide a string representation of this node's value.

Field Detail

NIL

protected static final Tree.Node NIL

NIL is the sentinal Node that is used instead of null, simplifying the implementation of the red/black tree.

ABOVE

protected static final int ABOVE

See Also:

Constant Field Values

LEFT

protected static final int LEFT

See Also:

Constant Field Values

SITTING

protected static final int SITTING

See Also:

Constant Field Values

RIGHT

protected static final int RIGHT

See Also:

Constant Field Values

current

protected Tree.Node current

fromdir

protected int fromdir

Constructor Detail

Tree.Crawler

public Tree.Crawler(Tree.Node head)

Crawler constructor.

Tree.Crawler

protected Tree.Crawler(Tree.Node head,
                       int fromdir)

Crawler constructor.

Method Detail

hasMoreElements

public boolean hasMoreElements()

Tests if this enumeration contains more elements.

Specified by:

hasMoreElements in interface Enumeration

nextElement

public Object nextElement()

Returns the next element of this enumeration.

Specified by:

nextElement in interface Enumeration

toString

public String toString()

Provide a string representation of this node's value.

clone

public Object clone()

Make a shallow copy of the node crawler.