brs
Class EmptyNode<T>

java.lang.Object
  brs.ANode<T>
      brs.EmptyNode<T>

 class EmptyNode<T>
extends ANode<T>

Represents the empty state of a BiTree. Uses the singleton pattern to model the uniqueness of "emptiness".

Since:

03/11/02

Constructor Summary

EmptyNode()

Method Summary

(package private) <R,P> R	execute(BiTree<T> owner, IVisitor<T,R,P> algo, P... inp) Calls algo's emptyCase () method to execute the algorithm algo.
(package private) BiTree<T>	getLeftSubTree(BiTree<T> owner) Throws java.util.NoSuchElementException.
(package private) BiTree<T>	getRightSubTree(BiTree<T> owner) Throws java.util.NoSuchElementException.
(package private) T	getRootDat(BiTree<T> owner) Throws java.util.NoSuchElementException.
(package private) void	insertRoot(BiTree<T> owner, T dat) Asks the owner tree to set the root node to a new DatNode containing dat, resulting in a state change from empty to non-empty.
(package private) T	remRoot(BiTree<T> owner) Throws java.util.NoSuchElementException.
(package private) void	setLeftSubTree(BiTree<T> owner, BiTree<T> biTree) Throws java.util.NoSuchElementException.
(package private) void	setRightSubTree(BiTree<T> owner, BiTree<T> biTree) Throws java.util.NoSuchElementException.
(package private) void	setRootDat(BiTree<T> owner, T dat) Throws java.util.NoSuchElementException.

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyNode

EmptyNode()

Method Detail

getRootDat

T getRootDat(BiTree<T> owner)

Throws java.util.NoSuchElementException.

Specified by:

getRootDat in class ANode<T>

Parameters:

owner - the BiTree holding this EmptyNode.

Returns:

the data element of this node if it exists.

setRootDat

void setRootDat(BiTree<T> owner,
                T dat)

Throws java.util.NoSuchElementException.

Specified by:

setRootDat in class ANode<T>

Parameters:

dat - a data Object.

owner - the BiTree holding this EmptyNode.

getLeftSubTree

BiTree<T> getLeftSubTree(BiTree<T> owner)

Throws java.util.NoSuchElementException.

Specified by:

getLeftSubTree in class ANode<T>

Parameters:

owner - the BiTree holding this EmptyNode.

Returns:

the left subtree of this node if it exists.

getRightSubTree

BiTree<T> getRightSubTree(BiTree<T> owner)

Throws java.util.NoSuchElementException.

Specified by:

getRightSubTree in class ANode<T>

Parameters:

owner - the BiTree holding this EmptyNode.

Returns:

the right subtree of this node if it exists.

setLeftSubTree

void setLeftSubTree(BiTree<T> owner,
                    BiTree<T> biTree)

Throws java.util.NoSuchElementException.

Specified by:

setLeftSubTree in class ANode<T>

Parameters:

biTree - a given BiTree.

owner - the BiTree holding this EmptyNode.

setRightSubTree

void setRightSubTree(BiTree<T> owner,
                     BiTree<T> biTree)

Throws java.util.NoSuchElementException.

Specified by:

setRightSubTree in class ANode<T>

Parameters:

biTree - a given BiTree.

owner - the BiTree holding this EmptyNode.

insertRoot

void insertRoot(BiTree<T> owner,
                T dat)

Asks the owner tree to set the root node to a new DatNode containing dat, resulting in a state change from empty to non-empty.

Specified by:

insertRoot in class ANode<T>

Parameters:

dat - a given data Object.

owner - the context of this state.

remRoot

T remRoot(BiTree<T> owner)

Throws java.util.NoSuchElementException.

Specified by:

remRoot in class ANode<T>

Parameters:

owner - the BiTree holding this EmptyNode.

execute

<R,P> R execute(BiTree<T> owner,
                IVisitor<T,R,P> algo,
                P... inp)

Calls algo's emptyCase () method to execute the algorithm algo.

Specified by:

execute in class ANode<T>

Parameters:

owner - the BiTree holding this EmptyNode.

algo - the visiting algorithm

inp - the vararg input algo needs.

Returns:

the output for the emptyCase() of algo.