/**
* 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.rif.model;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.items.Item;
import lupos.datastructures.items.literal.Literal;
import lupos.datastructures.items.literal.URILiteral;
import lupos.rif.IExpression;
import lupos.rif.IRuleVisitor;
import lupos.rif.RIFException;
import lupos.rif.builtin.Argument;
import lupos.rif.builtin.RIFBuiltinFactory;
import com.google.common.collect.Multimap;
public class External extends Uniterm {
private Object cachedResult;
private boolean doBind = false;
public External() {
super();
}
public External(Uniterm from) {
this();
this.termName = from.termName;
this.termName.setParent(this);
this.termParams.addAll(from.termParams);
for (IExpression expr : termParams)
expr.setParent(this);
}
@Override
public String getLabel() {
return "External: " + super.getLabel();
}
public <R, A> R accept(IRuleVisitor<R, A> visitor, A arg) throws RIFException {
return visitor.visit(this, arg);
}
public Object evaluate(Bindings binding) {
return evaluate(binding, null);
}
public Object evaluate(Bindings binding, Object optionalResult) {
return evaluate(binding, optionalResult, null);
}
public Object evaluate(Bindings binding, Object optionalResult, Multimap<IExpression, IExpression> equalities) {
final URILiteral name = (URILiteral) ((Constant) termName).getLiteral();
// Definiert?
if (!RIFBuiltinFactory.isDefined(name))
throw new RIFException("Builtin " + name.toString()
+ " not defined!");
// Bindung notwendig?
// if (!doBind
// && !(Sets
// .intersection(getVariables(), binding.getVariableSet())
// .size() != binding.getVariableSet().size()))
// doBind = true;
if (cachedResult == null) {
final List<Item> params = new ArrayList<Item>();
for (IExpression expr : termParams)
params.add((Item) expr.evaluate(binding, null, equalities));
final Argument arg = RIFBuiltinFactory.createArgument(binding,
(Literal) optionalResult, params.toArray(new Item[] {}));
if (getVariables().isEmpty())
return (cachedResult = RIFBuiltinFactory.callBuiltin(name, arg));
else
return RIFBuiltinFactory.callBuiltin(name, arg);
} else
return cachedResult;
}
public boolean isBound(RuleVariable var, Collection<RuleVariable> boundVars) {
if (getVariables().contains(var)
&& !boundVars.contains(var)
&& (RIFBuiltinFactory
.canBind((URILiteral) ((Constant) termName)
.getLiteral()))
|| RIFBuiltinFactory
.isIterable((URILiteral) ((Constant) termName)
.getLiteral())) {
boundVars.add(var);
return true;
} else
return false;
}
public boolean isPossibleAssignment() {
return false;
}
@Override
public boolean equalsDataStructure(final Object triple) {
return false;
}
@Override
public boolean equals(Object obj) {
if (obj != null && obj instanceof External) {
final External pred = (External) obj;
if (!pred.termName.equals(termName))
return false;
if (pred.termParams.size() != termParams.size())
return false;
for (int i = 0; i < termParams.size(); i++) {
if (!termParams.get(i).equals(pred.termParams.get(i)))
return false;
}
return true;
} else
return false;
}
@Override
public int hashCode() {
return toString().hashCode();
}
}