/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program 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; version 2 of the License.
This program 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
*/
/*
* Created on Jun 19, 2008
*/
package com.bigdata.bop;
/**
* A constant.
* <p>
* Note: {@link IConstant} does not implement {@link Comparable} for two
* reasons:
* <ol>
* <li>{@link Constant}s wrapping different data types are not comparable. Rigid
* schema data models such as SQL do not have this problem since columns have a
* single data type, but schema flexible object models and RDF both have runtime
* determination of the data type.</li>
* <li>The specifics of the ordering to be imposed are generally determined by a
* high level query language (SPARQL, XQUERY, SQL, etc). Thus even if this
* interface was {@link Comparable}, SORT operators generally must provide their
* own ordering semantics.</li>
* </ol>
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public interface IConstant<E> extends IVariableOrConstant<E> {
/**
* The hash code of the value that would be returned by
* {@link IVariableOrConstant#get()}
*/
int hashCode();
}