| /* |
| * 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.op ; |
| |
| import java.util.Objects; |
| |
| import org.apache.jena.sparql.algebra.Op ; |
| import org.apache.jena.sparql.algebra.OpVisitor ; |
| import org.apache.jena.sparql.algebra.Transform ; |
| import org.apache.jena.sparql.core.Var ; |
| import org.apache.jena.sparql.core.VarExprList ; |
| import org.apache.jena.sparql.expr.Expr ; |
| import org.apache.jena.sparql.sse.Tags ; |
| import org.apache.jena.sparql.util.NodeIsomorphismMap ; |
| |
| /** |
| * This is the operation in standard SPARQL 1.1 OpAssign is specifically in |
| * support of LET. |
| */ |
| public class OpExtend extends OpExtendAssign { |
| // There factory operations compress nested assignments if possible. |
| // Not possible if it's the reassignment of something already assigned. |
| |
| /** Create an OpExtend or add to an existing one. |
| * This cooperation collapses what would otherwise be stacks |
| * of OpExtend. |
| */ |
| static public Op extend(Op op, Var var, Expr expr) { |
| if ( !(op instanceof OpExtend) ) |
| return create(op, var, expr) ; |
| |
| OpExtend opExtend = (OpExtend)op ; |
| if ( opExtend.assignments.contains(var) ) |
| return create(op, var, expr) ; |
| |
| opExtend.assignments.add(var, expr) ; |
| return opExtend ; |
| } |
| |
| /** Create an OpExtend or add to an existing one. |
| * This operation collapses what would otherwise be stacks |
| * of OpExtend. |
| */ |
| static public Op extend(Op op, VarExprList exprs) { |
| if ( !(op instanceof OpExtend) ) |
| return create(op, exprs) ; |
| |
| OpExtend opExtend = (OpExtend)op ; |
| for (Var var : exprs.getVars()) { |
| if ( opExtend.assignments.contains(var) ) |
| return create(op, exprs) ; |
| } |
| |
| opExtend.assignments.addAll(exprs) ; |
| return opExtend ; |
| } |
| |
| /** Make a OpExtend - this does not aggregate (extend .. (extend ...)) */ |
| public static OpExtend create(Op op, VarExprList exprs) { |
| return new OpExtend(op, exprs) ; |
| } |
| |
| /** Make a OpExtend - this does not aggregate (extend .. (extend ...)) */ |
| public static Op create(Op op, Var var, Expr expr) { |
| VarExprList x = new VarExprList() ; |
| x.add(var, expr) ; |
| return new OpExtend(op, x) ; |
| } |
| |
| private OpExtend(Op subOp) { |
| super(subOp) ; |
| } |
| |
| private OpExtend(Op subOp, VarExprList exprs) { |
| super(subOp, exprs) ; |
| } |
| |
| @Override |
| public String getName() { |
| return Tags.tagExtend ; |
| } |
| |
| @Override |
| public void visit(OpVisitor opVisitor) { |
| opVisitor.visit(this) ; |
| } |
| |
| @Override |
| public Op1 copy(Op subOp) { |
| OpExtend op = new OpExtend(subOp, new VarExprList(getVarExprList())) ; |
| return op ; |
| } |
| |
| @Override |
| public boolean equalTo(Op other, NodeIsomorphismMap labelMap) { |
| if ( !(other instanceof OpExtend) ) |
| return false ; |
| OpExtend assign = (OpExtend)other ; |
| |
| if ( !Objects.equals(assignments, assign.assignments) ) |
| return false ; |
| return getSubOp().equalTo(assign.getSubOp(), labelMap) ; |
| } |
| |
| @Override |
| public Op apply(Transform transform, Op subOp) { |
| return transform.transform(this, subOp) ; |
| } |
| |
| @Override |
| public OpExtendAssign copy(Op subOp, VarExprList varExprList) { |
| return new OpExtend(subOp, varExprList) ; |
| } |
| } |