lrs
Class EmptyNode

java.lang.Object
  lrs.ANode
      lrs.EmptyNode

 class EmptyNode
extends ANode

Represents the empty state of a mutable list LRStruct. Uses the Singleton pattern.

Since:

10/09/01

Author:

Dung X. Nguyen Copyright 2001 - All rights reserved.

Field Summary

(package private) static EmptyNode

Singleton Singleton Pattern.

Constructor Summary

private

EmptyNode()

Method Summary

(package private) java.lang.Object	execute(IAlgo algo, java.lang.Object inp, LRStruct owner) Calls the IAlgo visitor's empty case.
(package private) java.lang.Object	getFirst(LRStruct owner) Throws java.util.NoSuchElementException.
(package private) LRStruct	getRest(LRStruct owner) Throws java.util.NoSuchElementException.
(package private) LRStruct	insertFront(java.lang.Object dat, LRStruct owner) The owner becomes non-empty and has dat as its first element.
(package private) java.lang.Object	removeFront(LRStruct owner) Throws java.util.NoSuchElementException.
(package private) LRStruct	setFirst(java.lang.Object dat, LRStruct owner) Throws java.util.NoSuchElementException.
(package private) LRStruct	setRest(LRStruct tail, LRStruct owner) Throws java.util.NoSuchElementException.

Methods inherited from class lrs.ANode

toString

Methods inherited from class java.lang.Object

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

Field Detail

Singleton

static final EmptyNode Singleton

Singleton Pattern.

Constructor Detail

EmptyNode

private EmptyNode()

Method Detail

getRest

LRStruct getRest(LRStruct owner)

Throws java.util.NoSuchElementException.

Specified by:

getRest in class ANode

Parameters:

owner - the LRStruct referencing this ANode.

Returns:

the rest LRStruct of owner.

getFirst

java.lang.Object getFirst(LRStruct owner)

Throws java.util.NoSuchElementException.

Specified by:

getFirst in class ANode

Parameters:

owner - the LRStruct referencing this ANode.

Returns:

the rest LRStruct of owner.

setRest

LRStruct setRest(LRStruct tail,
                 LRStruct owner)

Throws java.util.NoSuchElementException.

Specified by:

setRest in class ANode

Parameters:

tail - the new rest for the owner LRStruct.

owner - the LRS referencing this ANode.

Returns:

LRStruct owner

setFirst

LRStruct setFirst(java.lang.Object dat,
                  LRStruct owner)

Throws java.util.NoSuchElementException.

Specified by:

setFirst in class ANode

owner - the LRS referencing this ANode.

Returns:

LRStruct owner

insertFront

LRStruct insertFront(java.lang.Object dat,
                     LRStruct owner)

The owner becomes non-empty and has dat as its first element.

Specified by:

insertFront in class ANode

Parameters:

dat - the object to be inserted at the front.

owner - the LRS referencing this ANode.

Returns:

LRStruct owner

removeFront

java.lang.Object removeFront(LRStruct owner)

Throws java.util.NoSuchElementException.

Specified by:

removeFront in class ANode

Parameters:

owner - the LRS referencing this ANode.

Returns:

the front data of the LRStruct owner.

execute

java.lang.Object execute(IAlgo algo,
                         java.lang.Object inp,
                         LRStruct owner)

Calls the IAlgo visitor's empty case.

Specified by:

execute in class ANode

Parameters:

algo - the visitor algorithm to be executed.

inp - the input needed by the algorithm.

owner - the LRStruct referencing this ANode.