/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sparql.syntax;
import java.util.Iterator ;
import java.util.Set ;
import com.hp.hpl.jena.graph.Triple ;
import com.hp.hpl.jena.sparql.core.TriplePath ;
import com.hp.hpl.jena.sparql.core.Var ;
import com.hp.hpl.jena.sparql.core.VarExprList ;
import com.hp.hpl.jena.sparql.util.VarUtils ;
public class PatternVarsVisitor extends ElementVisitorBase
{
public Set<Var> acc ;
public PatternVarsVisitor(Set<Var> s) { acc = s ; }
@Override
public void visit(ElementTriplesBlock el)
{
for (Iterator<Triple> iter = el.patternElts() ; iter.hasNext() ; )
{
Triple t = iter.next() ;
VarUtils.addVarsFromTriple(acc, t) ;
}
}
@Override
public void visit(ElementPathBlock el)
{
for (Iterator<TriplePath> iter = el.patternElts() ; iter.hasNext() ; )
{
TriplePath tp = iter.next() ;
// If it's triple-izable, then use the triple.
if ( tp.isTriple() )
VarUtils.addVarsFromTriple(acc, tp.asTriple()) ;
else
VarUtils.addVarsFromTriplePath(acc, tp) ;
}
}
// Variables here are non-binding.
@Override public void visit(ElementExists el) { }
@Override public void visit(ElementNotExists el) { }
@Override public void visit(ElementMinus el) { }
@Override public void visit(ElementFilter el) { }
@Override
public void visit(ElementNamedGraph el)
{
VarUtils.addVar(acc, el.getGraphNameNode()) ;
}
@Override
public void visit(ElementSubQuery el)
{
el.getQuery().setResultVars() ;
VarExprList x = el.getQuery().getProject() ;
acc.addAll(x.getVars()) ;
// And any GROUP BY
x = el.getQuery().getGroupBy() ;
acc.addAll(x.getVars()) ;
}
@Override
public void visit(ElementAssign el)
{
acc.add(el.getVar()) ;
}
@Override
public void visit(ElementBind el)
{
acc.add(el.getVar()) ;
}
// @Override
// public void visit(ElementService el)
// {
// // Although if this isn't defined elsewhere the query won't work.
// VarUtils.addVar(acc, el.getServiceNode()) ;
// }
}