/**
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
*/
package com.bigdata.rdf.sparql.ast;
import java.util.Map;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IValueExpression;
import com.bigdata.rdf.internal.IV;
/**
* An {@link IValueExpressionNode} paired with a flag to indicating an ascending
* or descending sort order.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class OrderByExpr extends ASTBase implements
IValueExpressionNodeContainer {
/**
*
*/
private static final long serialVersionUID = 1L;
interface Annotations extends ASTBase.Annotations {
String ASCENDING = "ascending";
boolean DEFAULT_ASCENDING = true;
}
/**
* Constructor required for {@link com.bigdata.bop.BOpUtility#deepCopy(FilterNode)}.
*/
public OrderByExpr(OrderByExpr op) {
super(op);
}
/**
* Required shallow copy constructor.
*/
public OrderByExpr(BOp[] args, Map<String, Object> annotations) {
super(args, annotations);
}
public OrderByExpr(final IValueExpressionNode ve, final boolean ascending) {
super(new BOp[] { (BOp) ve }, null/* anns */);
setAscending(ascending);
}
final public boolean isAscending() {
return getProperty(Annotations.ASCENDING, Annotations.DEFAULT_ASCENDING);
}
final public void setAscending(boolean ascending) {
setProperty(Annotations.ASCENDING, ascending);
}
public IValueExpressionNode getValueExpressionNode() {
return (IValueExpressionNode) get(0);
}
public IValueExpression<? extends IV> getValueExpression() {
return getValueExpressionNode().getValueExpression();
}
// public String toString() {
//
// final StringBuilder sb = new StringBuilder();
//
// final boolean ascending = isAscending();
//
// if (!ascending) {
//
// sb.append("desc(");
//
// }
//
// sb.append(getValueExpressionNode().toString());
//
// if (!ascending) {
//
// sb.append(")");
//
// }
//
// return sb.toString();
//
// }
}