/*
 * $Header$
 * $Revision: 1261 $
 * $Date: 2006-11-30 10:49:27 -0800 (Thu, 30 Nov 2006) $
 *
 * ====================================================================
 *
 * 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: DefaultEqualsExpr.java 1261 2006-11-30 18:49:27Z elharo $
 */



package org.jaxen.expr;

import org.jaxen.function.NumberFunction;

class DefaultEqualsExpr extends DefaultEqualityExpr {
    
    /**
     * 
     */
    private static final long serialVersionUID = -8327599812627931648L;
    
  DefaultEqualsExpr( Expr lhs, Expr rhs )
    {
    super( lhs, rhs );
    }

  public String getOperator()
    {
    return "=";
    }

  public String toString()
    {
    return "[(DefaultEqualsExpr): " + getLHS() + ", " + getRHS() + "]";
    }
  
  protected boolean evaluateObjectObject( Object lhs, Object rhs )
    {
    if( eitherIsNumber( lhs, rhs ) )
      {
      if( NumberFunction.isNaN( (Double) lhs ) || NumberFunction.isNaN( (Double) rhs ) )
        {
        return false;
        }
      }
    
    return lhs.equals( rhs );
    }

}
