structure
Class DoublyLinkedListIterator

java.lang.Object
  structure.AbstractIterator
      structure.DoublyLinkedListIterator

All Implemented Interfaces:

java.util.Enumeration, java.util.Iterator

public class DoublyLinkedListIterator
extends AbstractIterator

A private iterator for traversing a doubly linked list.

Field Summary

protected DoublyLinkedNode	current Reference to the current node in the list.
protected DoublyLinkedNode	head Reference to head of the list.
protected DoublyLinkedNode	tail Sign of the end of the list.

Constructor Summary

DoublyLinkedListIterator(DoublyLinkedNode h)
Construct an iterator over a doubly linked list hanging from head.

DoublyLinkedListIterator(DoublyLinkedNode headDummy, DoublyLinkedNode tailDummy)

Method Summary

java.lang.Object	get() Get reference to value that is current.
boolean	hasNext() Determine if there are more elements to be considered.
java.lang.Object	next() Returns reference to the current element, then increments iterator.
void	reset() Reset the iterator to the head of the list.

Methods inherited from class structure.AbstractIterator

hasMoreElements, nextElement, remove, value

Methods inherited from class java.lang.Object

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

Field Detail

head

protected DoublyLinkedNode head

Reference to head of the list.

tail

protected DoublyLinkedNode tail

Sign of the end of the list.

current

protected DoublyLinkedNode current

Reference to the current node in the list.

Constructor Detail

DoublyLinkedListIterator

public DoublyLinkedListIterator(DoublyLinkedNode h)

Construct an iterator over a doubly linked list hanging from head.

Parameters:

h - The head of the list to be traversed.

Postcondition:

constructs an iterator rooted at list head, h

DoublyLinkedListIterator

public DoublyLinkedListIterator(DoublyLinkedNode headDummy,
                                DoublyLinkedNode tailDummy)

Method Detail

reset

public void reset()

Reset the iterator to the head of the list.

Specified by:

reset in class AbstractIterator

Postcondition:

resets iterator to list head

hasNext

public boolean hasNext()

Determine if there are more elements to be considered.

Specified by:

hasNext in interface java.util.Iterator

Specified by:

hasNext in class AbstractIterator

Returns:

True iff there are more elements to be considered.

See Also:

AbstractIterator.hasMoreElements()

Postcondition:

returns true iff current element is valid

next

public java.lang.Object next()

Returns reference to the current element, then increments iterator.

Specified by:

next in interface java.util.Iterator

Specified by:

next in class AbstractIterator

Returns:

Reference to element that was current before increment.

See Also:

AbstractIterator.hasMoreElements(), AbstractIterator.value()

Postcondition:

returns current element and increments iterator

get

public java.lang.Object get()

Get reference to value that is current.

Specified by:

get in class AbstractIterator

Returns:

A reference to the value that is current.

Precondition:

hasNext

Postcondition:

returns current element