| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 1999 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 1999, Lotus |
| * Development Corporation., http://www.lotus.com. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.xml.utils; |
| |
| import java.util.EmptyStackException; |
| |
| /** |
| * <meta name="usage" content="internal"/> |
| * Simple stack for boolean values. |
| */ |
| public final class BoolStack implements Cloneable |
| { |
| |
| /** Array of boolean values */ |
| private boolean m_values[]; |
| |
| /** Array size allocated */ |
| private int m_allocatedSize; |
| |
| /** Index into the array of booleans */ |
| private int m_index; |
| |
| /** |
| * Default constructor. Note that the default |
| * block size is very small, for small lists. |
| */ |
| public BoolStack() |
| { |
| this(32); |
| } |
| |
| /** |
| * Construct a IntVector, using the given block size. |
| * |
| * @param size array size to allocate |
| */ |
| public BoolStack(int size) |
| { |
| |
| m_allocatedSize = size; |
| m_values = new boolean[size]; |
| m_index = -1; |
| } |
| |
| /** |
| * Get the length of the list. |
| * |
| * @return Current length of the list |
| */ |
| public final int size() |
| { |
| return m_index + 1; |
| } |
| |
| /** |
| * Pushes an item onto the top of this stack. |
| * |
| * |
| * @param val the boolean to be pushed onto this stack. |
| * @return the <code>item</code> argument. |
| */ |
| public final boolean push(boolean val) |
| { |
| |
| if (m_index == m_allocatedSize - 1) |
| grow(); |
| |
| return (m_values[++m_index] = val); |
| } |
| |
| /** |
| * Removes the object at the top of this stack and returns that |
| * object as the value of this function. |
| * |
| * @return The object at the top of this stack. |
| * @throws EmptyStackException if this stack is empty. |
| */ |
| public final boolean pop() |
| { |
| return m_values[m_index--]; |
| } |
| |
| /** |
| * Removes the object at the top of this stack and returns the |
| * next object at the top as the value of this function. |
| * |
| * |
| * @return Next object to the top or false if none there |
| */ |
| public final boolean popAndTop() |
| { |
| |
| m_index--; |
| |
| return (m_index >= 0) ? m_values[m_index] : false; |
| } |
| |
| /** |
| * Set the item at the top of this stack |
| * |
| * |
| * @param b Object to set at the top of this stack |
| */ |
| public final void setTop(boolean b) |
| { |
| m_values[m_index] = b; |
| } |
| |
| /** |
| * Looks at the object at the top of this stack without removing it |
| * from the stack. |
| * |
| * @return the object at the top of this stack. |
| * @throws EmptyStackException if this stack is empty. |
| */ |
| public final boolean peek() |
| { |
| return m_values[m_index]; |
| } |
| |
| /** |
| * Looks at the object at the top of this stack without removing it |
| * from the stack. If the stack is empty, it returns false. |
| * |
| * @return the object at the top of this stack. |
| */ |
| public final boolean peekOrFalse() |
| { |
| return (m_index > -1) ? m_values[m_index] : false; |
| } |
| |
| /** |
| * Looks at the object at the top of this stack without removing it |
| * from the stack. If the stack is empty, it returns true. |
| * |
| * @return the object at the top of this stack. |
| */ |
| public final boolean peekOrTrue() |
| { |
| return (m_index > -1) ? m_values[m_index] : true; |
| } |
| |
| /** |
| * Tests if this stack is empty. |
| * |
| * @return <code>true</code> if this stack is empty; |
| * <code>false</code> otherwise. |
| */ |
| public boolean isEmpty() |
| { |
| return (m_index == -1); |
| } |
| |
| /** |
| * Grows the size of the stack |
| * |
| */ |
| private void grow() |
| { |
| |
| m_allocatedSize *= 2; |
| |
| boolean newVector[] = new boolean[m_allocatedSize]; |
| |
| System.arraycopy(m_values, 0, newVector, 0, m_index + 1); |
| |
| m_values = newVector; |
| } |
| |
| public Object clone() |
| throws CloneNotSupportedException |
| { |
| return super.clone(); |
| } |
| |
| } |