/*
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.rules;
import java.util.Map;
import com.bigdata.bop.BOp;
import com.bigdata.bop.BOpBase;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IConstant;
import com.bigdata.bop.IVariable;
import com.bigdata.bop.constraint.BooleanValueExpression;
/**
* Rejects (x y z) iff x==z and y==owl:sameAs, where x, y, and z are variables.
*/
public class RejectAnythingSameAsItself extends BOpBase
implements BooleanValueExpression {
/**
*
*/
private static final long serialVersionUID = -44020295153412258L;
/**
* Required shallow copy constructor.
*/
public RejectAnythingSameAsItself(final BOp[] values,
final Map<String, Object> annotations) {
super(values, annotations);
}
/**
* Constructor required for {@link com.bigdata.bop.BOpUtility#deepCopy(FilterNode)}.
*/
public RejectAnythingSameAsItself(final RejectAnythingSameAsItself op) {
super(op);
}
/**
*
* @param s
* @param p
* @param o
* @param owlSameAs
*/
public RejectAnythingSameAsItself(final IVariable<Long> s,
final IVariable<Long> p, final IVariable<Long> o,
final IConstant<Long> owlSameAs) {
super(new BOp[] { s, p, o, owlSameAs }, null/*annotations*/);
if (s == null || p == null || o == null || owlSameAs == null)
throw new IllegalArgumentException();
}
@SuppressWarnings("unchecked")
public Boolean get(final IBindingSet bindingSet) {
// get binding for "x".
final IConstant<Long> s = bindingSet.get((IVariable<?>) get(0)/* s */);
if (s == null)
return true; // not yet bound.
// get binding for "y".
final IConstant<Long> p = bindingSet.get((IVariable<?>) get(1)/* p */);
if (p == null)
return true; // not yet bound.
// get binding for "z".
final IConstant<Long> o = bindingSet.get((IVariable<?>) get(2)/* o */);
if (o == null)
return true; // not yet bound.
if (s.equals(o) && p.equals(get(3)/* owlSameAs */)) {
// reject this case.
return false;
}
return true;
}
}