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/* -*- java -*- */
/**
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
{
/**
* Node for the list
*/
public class Node
{
/**
* Constructor
*
* @param value The value to store in the list
*/
private Node(T value)
{
this.value = value;
}
/**
* The value stored in the list by this node
*/
public T value;
/**
* The next node in the list
*/
public Node next = null;
£>if (( with_prev )); then
/**
* The previous node in the list
*/
public Node previous = null;
£>fi
}
£>if (( with_head )); then
/**
* The first node in the list
*/
public Node head = null;
£>fi
£>if (( with_tail )); then
/**
* The last node in the list
*/
public Node tail = null;
£>fi
£>if (( 1 - with_head )) && (( 1 - with_tail )); then
/**
* Creates the initial node in a circularly linked list
*
* @param value The value of the initial node
* @return The node that has been created and inserted
*/
public Node create(T value)
{
Node node = new Node(value);
£>(( with_prev )) &&
node.previous = node;
return node.next = node;
}
£>fi
£>if (( with_head )); then
/**
* Insert a value in the beginning of the list
*
* @param value The value to insert
* @return The node that has been created and inserted
*/
public Node insertBeginning(T value)
{
Node node = new Node(value);
node.next = this.head;
£>if (( with_prev )); then
if (node.next != null)
node.next.previous = node;
£>fi
£>if (( with_tail )); then
if (this.head == null)
this.tail = node;
£>fi
this.head = node;
return node;
}
/**
* Remove the node at the beginning of the list
*
* @return The node that has been removed
*/
public Node removeBeginning()
{
Node node = this.head;
if (node != null)
this.head = this.head.next;
£>if (( with_prev )); then
if (this.head != null)
this.head.previous = null;
£>fi
£>if (( with_tail )); then
if (this.tail == node)
this.tail = null;
£>fi
return node;
}
£>fi
/**
* Insert a value after a specified, reference, node
*
* @param value The value to insert
* @param predecessor The reference node
* @return The node that has been created and inserted
*/
public Node insertAfter(T value, Node predecessor)
{
Node node = new Node(value);
node.next = predecessor.next;
predecessor.next = node;
£>if (( with_prev )); then
node.previous = predecessor;
if (node.next != null)
node.next.previous = node;
£>fi
£>if (( with_tail )); then
if (this.tail == predecessor)
this.tail = node;
£>fi
return node;
}
/**
* Remove the node after a specified, reference, node
*
* @param predecessor The reference node
* @return The node that has been removed
*/
public Node removeAfter(Node predecessor)
{
Node node = predecessor.next;
if (node == null)
predecessor.next = node.next;
£>if (( with_prev )); then
else if (node.next != null)
node.next.previous = predecessor;
£>fi
£>if (( with_tail )); then
if (this.tail == node)
this.tail = predecessor;
£>fi
return node;
}
£>if (( with_prev )); then
/**
* Insert a value before a specified, reference, node
*
* @param value The value to insert
* @param successor The reference node
* @return The node that has been created and inserted
*/
public Node insertBefore(T value, Node successor)
{
Node node = new Node(value);
node.previous = successor.previous;
successor.previous = node;
node.next = successor;
if (node.previous != null)
node.previous.next = node;
£>if (( with_head )); then
if (this.head == successor)
this.head = node;
£>fi
return node;
}
/**
* Remove the node before a specified, reference, node
*
* @param successor The reference node
* @return The node that has been removed
*/
public Node removeBefore(Node successor)
{
Node node = successor.previous;
if (node == null)
successor.previous = node.previous;
else if (node.previous != null)
node.previous.next = successor;
£>if (( with_head )); then
if (this.head == node)
this.head = successor;
£>fi
return node;
}
/**
* Remove the node from the list
*
* @param node The node to remove
*/
public void remove(Node node)
{
if (node.previous != null)
node.previous.next = node.next;
£>if (( with_head )); then
else
this.head = node.next;
£>fi
if (node.next != null)
node.next.previous = node.previous;
£>if (( with_tail )); then
else
this.tail = node.previous;
£>fi
}
£>fi
£>if (( with_tail )); then
/**
* Insert a value in the end of the list
*
* @param value The value to insert
* @return The node that has been created and inserted
*/
public Node insertEnd(T value)
{
if (this.tail == null)
£>(( with_head )) &&
return insertBeginning(value);
£>(( with_head )) ||
return this.tail = new Node(value);
return insertAfter(value, this.tail);
}
£>if (( with_prev )); then
/**
* Remove the node at the end of the list
*
* @return The node that has been removed
*/
public Node removeEnd()
{
Node node = this.tail;
if (node != null)
(this.tail = node.previous).next = null;
return node;
}
£>fi
£>fi
}
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