/*
* JacORB - a free Java ORB
*
* Copyright (C) The JacORB project, 1997-2006.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.jacorb.util;
import java.util.EmptyStackException;
import java.util.LinkedList;
/**
* unsynchronized implementation of a stack (LIFO queue)
*
* @see java.util.Stack
* @author Alphonse Bendt
* @version $Id: Stack.java,v 1.1 2006-06-29 15:15:58 alphonse.bendt Exp $
*/
public class Stack
{
private final LinkedList elements = new LinkedList();
public boolean empty()
{
return elements.isEmpty();
}
public Object push(Object element)
{
elements.add(element);
return element;
}
public Object pop()
{
if (empty())
{
throw new EmptyStackException();
}
return elements.removeLast();
}
public Object peek()
{
if (empty())
{
throw new EmptyStackException();
}
return elements.getLast();
}
public int search(Object value)
{
final int result;
if (empty())
{
result = -1;
}
else
{
result = elements.size() - elements.lastIndexOf(value);
}
return result;
}
}