/**
* Copyright (c) 2013, Institute of Information Systems (Sven Groppe and contributors of LUPOSDATE), University of Luebeck
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
*
*/
package lupos.engine.operators.singleinput.sort;
import java.util.Collection;
import lupos.datastructures.items.Variable;
import lupos.engine.operators.BasicOperator;
import lupos.engine.operators.singleinput.SingleInputOperator;
import lupos.engine.operators.singleinput.sort.comparator.ComparatorAST;
import lupos.engine.operators.singleinput.sort.comparator.ComparatorBindings;
/**
* This is almost an abstract class, but as it needs to be
* instantiated in operatorPipe it is not. Nevertheless it should not be
* instantiated, as no useful results will be created.
* DO ONLY USE EXTENDING CLASSES
*/
public class Sort extends SingleInputOperator {
protected ComparatorBindings comparator; // Comparator which compares in order to sort
public Sort() {
}
/**
* Contructor
*
* @param node
* the current sort node. From this node all other informations
* like variables to sort after will be extracted.
*/
public Sort(final lupos.sparql1_1.Node node) {
comparator = new ComparatorAST(node);
}
@Override
public void cloneFrom(final BasicOperator op) {
super.cloneFrom(op);
comparator = ((Sort) op).getComparator();
}
public ComparatorBindings getComparator() {
return comparator;
}
public void setComparator(ComparatorBindings comparator) {
this.comparator=comparator;
}
@Override
public String toString() {
return super.toString() + "\nSortcriterium:" + getSortCriterium();
}
public Collection<Variable> getSortCriterium() {
return getComparator().getSortCriterium();
}
}