| /* |
| * 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.algebra.walker; |
| |
| import org.apache.jena.sparql.expr.* ; |
| import org.apache.jena.sparql.syntax.* ; |
| |
| /** An element visitor that walks the graph pattern tree for one query level. |
| * applying a visitor at each Element traversed.<br/> |
| * Does not process subqueries.<br/> |
| * Does not process (NOT)EXISTS in filters.<br/> |
| * These will need to call down themselves if it is meaningful for the visitor. |
| * Bottom-up walk - apply to subelements before applying to current element. |
| */ |
| |
| public class ElementWalker_New { |
| public static void walk(Element el, ElementVisitor visitor) { |
| walk(el, visitor, null) ; |
| } |
| |
| public static void walk(Element el, ElementVisitor elVisitor, ExprVisitor exprVisitor) { |
| EltWalker w = new EltWalker(elVisitor, exprVisitor) ; |
| el.visit(w) ; |
| } |
| |
| // protected static void walk$(Element el, Walker walker) { |
| // el.visit(walker) ; |
| // } |
| |
| static public class EltWalker implements ElementVisitor, ExprVisitorFunction { |
| protected final ElementVisitor elementVisitor ; |
| protected final ExprVisitor exprVisitor ; |
| |
| protected EltWalker(ElementVisitor visitor, ExprVisitor exprVisitor) { |
| this.elementVisitor = visitor ; |
| this.exprVisitor = exprVisitor ; |
| } |
| |
| @Override |
| public void visit(ElementTriplesBlock el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementFilter el) { |
| el.getExpr().visit(this); |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementAssign el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementBind el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementData el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementUnion el) { |
| for ( Element e : el.getElements() ) |
| e.visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementGroup el) { |
| for ( Element e : el.getElements() ) |
| e.visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementOptional el) { |
| if ( el.getOptionalElement() != null ) |
| el.getOptionalElement().visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementDataset el) { |
| if ( el.getElement() != null ) |
| el.getElement().visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementNamedGraph el) { |
| if ( el.getElement() != null ) |
| el.getElement().visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementService el) { |
| if ( el.getElement() != null ) |
| el.getElement().visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| // EXISTs, NOT EXISTs also occur in FILTERs via expressions. |
| |
| @Override |
| public void visit(ElementExists el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementNotExists el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementMinus el) { |
| if ( el.getMinusElement() != null ) |
| el.getMinusElement().visit(this) ; |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementSubQuery el) { |
| // This does not automatically walk into the subquery. |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ElementPathBlock el) { |
| elementVisitor.visit(el) ; |
| } |
| |
| @Override |
| public void visit(ExprFunction0 func) { visitExprFunction(func) ; } |
| @Override |
| public void visit(ExprFunction1 func) { visitExprFunction(func) ; } |
| @Override |
| public void visit(ExprFunction2 func) { visitExprFunction(func) ; } |
| @Override |
| public void visit(ExprFunction3 func) { visitExprFunction(func) ; } |
| @Override |
| public void visit(ExprFunctionN func) { visitExprFunction(func) ; } |
| |
| @Override |
| public void visitExprFunction(ExprFunction func) { |
| for ( int i = 1 ; i <= func.numArgs() ; i++ ) |
| { |
| Expr expr = func.getArg(i) ; |
| if ( expr == null ) |
| // Put a dummy in, e.g. to keep the transform stack aligned. |
| Expr.NONE.visit(this) ; |
| else |
| expr.visit(this) ; |
| } |
| func.visit(exprVisitor) ; |
| } |
| |
| @Override |
| public void visit(ExprFunctionOp funcOp) { |
| // Walk the op |
| funcOp.getElement().visit(this); |
| funcOp.visit(exprVisitor) ; |
| } |
| |
| @Override |
| public void visit(NodeValue nv) { nv.visit(exprVisitor) ; } |
| @Override |
| public void visit(ExprVar v) { v.visit(exprVisitor) ; } |
| @Override |
| public void visit(ExprNone v) { v.visit(exprVisitor) ; } |
| @Override |
| public void visit(ExprAggregator eAgg) { |
| //eAgg.getAggVar().visit(visitorExpr); |
| // XXX XXX Hack for varsMentioned |
| eAgg.visit(exprVisitor) ; |
| } |
| } |
| } |