001    /**
002     * =========================================
003     * LibFormula : a free Java formula library
004     * =========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/libformula/
007     *
008     * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     *
026     * ------------
027     * $Id: ExtendedComparator.java 2716 2007-04-01 13:51:58Z taqua $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.typing;
032    
033    /**
034     * A comparator, that offers type support. Unlike the plain Java-Comparator,
035     * this class is able to compare
036     *
037     * @author Thomas Morgner
038     */
039    public interface ExtendedComparator
040    {
041      public boolean isEqual(final Type type1,
042                             final Object value1,
043                             final Type type2,
044                             final Object value2);
045    
046      /**
047       * Returns null, if the types are not comparable and are not convertible at
048       * all.
049       *
050       * @param type1
051       * @param value1
052       * @param type2
053       * @param value2
054       * @return
055       */
056      public Integer compare(final Type type1,
057                             final Object value1,
058                             final Type type2,
059                             final Object value2);
060    }