/*
 * SubstringAfterFunction.java
 * Copyright (C) 2004 The Free Software Foundation
 * 
 * This file is part of GNU JAXP, a library.
 *
 * GNU JAXP is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * GNU JAXP 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library.  Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obliged to do so.  If you do not wish to do so, delete this
 * exception statement from your version. 
 */

package gnu.xml.xpath;

import java.util.List;
import org.w3c.dom.Node;

/**
 * The <code>substring-after</code> function returns the substring of the
 * first argument string that follows the first occurrence of the second
 * argument string in the first argument string, or the empty string if the
 * first argument string does not contain the second argument string. For
 * example, substring-after("1999/04/01","/") returns 04/01, and
 * substring-after("1999/04/01","19") returns 99/04/01.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
final class SubstringAfterFunction
  extends Expr
{

  final Expr arg1;
  final Expr arg2;

  SubstringAfterFunction(List args)
  {
    this((Expr) args.get(0), (Expr) args.get(1));
  }

  SubstringAfterFunction(Expr arg1, Expr arg2)
  {
    this.arg1 = arg1;
    this.arg2 = arg2;
  }

  public Object evaluate(Node context, int pos, int len)
  {
    Object val1 = arg1.evaluate(context, pos, len);
    Object val2 = arg2.evaluate(context, pos, len);
    String s1 = _string(context, val1);
    String s2 = _string(context, val2);
    int index = s1.indexOf(s2);
    return (index == -1) ? "" : s1.substring(index + s2.length());
  }

  public Expr clone(Object context)
  {
    return new SubstringAfterFunction(arg1.clone(context),
                                      arg2.clone(context));
  }

  public String toString()
  {
    return "substring-after(" + arg1 + "," + arg2 + ")";
  }
  
}
