/*

  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/saxpath/Axis.java,v 1.8 2006/03/30 13:56:36 elharo Exp $

  * $Revision: 1.8 $

  * $Date: 2006/03/30 13:56:36 $

  *

  * ====================================================================

  *

  * Copyright 2000-2002 bob mcwhirter & James Strachan.

  * All rights reserved.

  *

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are

  * met:

  * 

  *   * Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  * 

  *   * 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.

  * 

  *   * Neither the name of the Jaxen Project nor the names of its

  *     contributors may be used to endorse or promote products derived 

  *     from this software without specific prior written permission.

  * 

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

  * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER

  * OR 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 Jaxen Project and was originally

  * created by bob mcwhirter <bob@werken.com> and

  * James Strachan <jstrachan@apache.org>.  For more information on the

  * Jaxen Project, please see <http://www.jaxen.org/>.

  *

  * $Id: Axis.java,v 1.8 2006/03/30 13:56:36 elharo Exp $

  */

 package org.jaxen.saxpath;

 import org.jaxen.JaxenRuntimeException;

 /**

  * 

  * Internal SAXPath class that contains constants representing 

  * XPath operators to avoid a lot of string comparisons. 

  */

 public class Axis

 {

     private Axis() {}

     // XXX Ultimately these should use the type-safe enum pattern instead

     /** Marker for an invalid axis */

     public final static int INVALID_AXIS       =  0;

     /** The <code>child</code> axis */

     public final static int CHILD              =  1;

     /** The <code>descendant</code> axis */

     public final static int DESCENDANT         =  2;

     /** The <code>parent</code> axis */

     public final static int PARENT             =  3;

     /** The <code>ancestor</code> axis */

     public final static int ANCESTOR           =  4;

     /** The <code>following-sibling</code> axis */

     public final static int FOLLOWING_SIBLING  =  5;

     /** The <code>preceding-sibling</code> axis */

     public final static int PRECEDING_SIBLING  =  6;

     /** The <code>following</code> axis */

     public final static int FOLLOWING          =  7;

     /** The <code>preceding</code> axis */

     public final static int PRECEDING          =  8;

     /** The <code>attribute</code> axis */

     public final static int ATTRIBUTE          =  9;

     /** The <code>namespace</code> axis */

     public final static int NAMESPACE          = 10;

     /** The <code>self</code> axis */

     public final static int SELF               = 11;

     /** The <code>descendant-or-self</code> axis */

     public final static int DESCENDANT_OR_SELF = 12;

     /** The <code>ancestor-or-self</code> axis */

     public final static int ANCESTOR_OR_SELF   = 13;

     /**

      * <p>

      * Returns the name of the axis.

      * </p>

      * 

      * @param axisNum the axis code

      * @return the name of the axis such as might be used in an XPath expression

      * @throws JaxenRuntimeException if the number does not represent one of the 13

      *     XPath axes

      */

     public static String lookup(int axisNum)

     {

         switch ( axisNum )

         {

             case CHILD:

                 return "child";

             case DESCENDANT:

                 return "descendant";

             case PARENT:

                 return "parent";

             case ANCESTOR:

                 return "ancestor";

             case FOLLOWING_SIBLING:

                 return "following-sibling";

             case PRECEDING_SIBLING:

                 return "preceding-sibling";

             case FOLLOWING:

                 return "following";

             case PRECEDING:

                 return "preceding";

             case ATTRIBUTE:

                 return "attribute";

             case NAMESPACE:

                 return "namespace";

             case SELF:

                 return "self";

             case DESCENDANT_OR_SELF:

                 return "descendant-or-self";

             case ANCESTOR_OR_SELF:

                 return "ancestor-or-self";

         }

         throw new JaxenRuntimeException("Illegal Axis Number");

     }

     /**

      * <p>

      * Returns the code for an axis given its name.

      * </p>

      * 

      * @param axisName the name of the axis: child, parent, descendant, descendant-or-self, etc.

      * @return the axis code

      */

     public static int lookup(String axisName)

     {

         // XXX All these equals calls are a small HotSpot;

         // Need to replace this with a static HashMap

         if ( "child".equals( axisName ) )

         {

             return CHILD;

         }

         if ( "descendant".equals( axisName ) )

         {

             return DESCENDANT;

         }

         if ( "parent".equals( axisName ) )

         {

             return PARENT;

         }

         if ( "ancestor".equals( axisName ) )

         {

             return ANCESTOR;

         }

         if ( "following-sibling".equals( axisName ) )

         {

             return FOLLOWING_SIBLING;

         }

         if ( "preceding-sibling".equals( axisName ) )

         {

             return PRECEDING_SIBLING;

         }

         if ( "following".equals( axisName ) )

         {

             return FOLLOWING;

         }

         if ( "preceding".equals( axisName ) )

         {

             return PRECEDING;

         }

         if ( "attribute".equals( axisName ) )

         {

             return ATTRIBUTE;

         }

         if ( "namespace".equals( axisName ) )

         {

             return NAMESPACE;

         }

         if ( "self".equals( axisName ) )

         {

             return SELF;

         }

         if ( "descendant-or-self".equals( axisName ) )

         {

             return DESCENDANT_OR_SELF;

         }

         if ( "ancestor-or-self".equals( axisName ) )

         {

             return ANCESTOR_OR_SELF;

         }

         return INVALID_AXIS;

     }

 }