| /* |
| * 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 org.apache.jena.sparql.syntax; |
| |
| import java.util.Collection ; |
| import java.util.LinkedHashSet ; |
| |
| import org.apache.jena.sparql.core.Var ; |
| |
| /** Get the variables potentially bound by an element. |
| * All mentioned variables except those in MINUS and FILTER (and hence NOT EXISTS) |
| * The work is done by PatternVarsVisitor. |
| */ |
| public class PatternVars |
| { |
| public static Collection<Var> vars(Element element) { return vars(new LinkedHashSet<Var>(), element) ; } |
| |
| public static Collection<Var> vars(Collection<Var> s, Element element) |
| { |
| PatternVarsVisitor v = new PatternVarsVisitor(s) ; |
| vars(element, v) ; |
| return s ; |
| } |
| |
| public static void vars(Element element, PatternVarsVisitor visitor) |
| { |
| ElementWalker.EltWalker walker = new WalkerSkipMinus(visitor) ; |
| ElementWalker.walk$(element, walker) ; |
| } |
| |
| public static class WalkerSkipMinus extends ElementWalker.EltWalker |
| { |
| protected WalkerSkipMinus(ElementVisitor visitor) |
| { |
| super(visitor, null, null) ; |
| } |
| |
| @Override |
| public void visit(ElementMinus el) |
| { |
| // Don't go down the RHS of MINUS |
| //if ( el.getMinusElement() != null ) |
| // el.getMinusElement().visit(this) ; |
| proc.visit(el) ; |
| } |
| } |
| } |