/*
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;
/**
* Abstraction models either a constant or an unbound variable.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public interface IVariableOrConstant<E> extends IValueExpression<E> {
/**
* Return <code>true</code> iff this is a variable.
*/
boolean isVar();
/**
* Return <code>true</code> iff this is a constant.
*/
boolean isConstant();
/**
* Return <code>true</code> if this is the same variable or if both values
* are {@link Constant} whose values are the same.
*/
boolean equals(IVariableOrConstant<E> o);
/**
* Return the bound value.
*
* @throws UnsupportedOperationException
* if this is a variable.
*/
E get();
/**
* Return the name of a variable.
*
* @throws UnsupportedOperationException
* if this is not a variable.
*/
String getName();
}