001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.jxpath.ri.compiler; 018 019import org.apache.commons.jxpath.ri.EvalContext; 020import org.apache.commons.jxpath.ri.axes.UnionContext; 021 022/** 023 * Implementation of {@link Expression} for the operation "|". 024 * 025 * @author Dmitri Plotnikov 026 * @version $Revision: 652845 $ $Date: 2008-05-02 19:46:46 +0200 (Fr, 02 Mai 2008) $ 027 */ 028public class CoreOperationUnion extends CoreOperation { 029 030 /** 031 * Create a new CoreOperationUnion. 032 * @param args Expression[] 033 */ 034 public CoreOperationUnion(Expression[] args) { 035 super(args); 036 } 037 038 public Object computeValue(EvalContext context) { 039 EvalContext[] argCtxs = new EvalContext[args.length]; 040 for (int i = 0; i < args.length; i++) { 041 Object value = args[i].compute(context); 042 if (value instanceof EvalContext) { 043 argCtxs[i] = (EvalContext) value; 044 } 045 else { 046 argCtxs[i] = context.getRootContext().getConstantContext(value); 047 } 048 } 049 return new UnionContext(context.getRootContext(), argCtxs); 050 } 051 052 protected int getPrecedence() { 053 return UNION_PRECEDENCE; 054 } 055 056 protected boolean isSymmetric() { 057 return true; 058 } 059 060 public String getSymbol() { 061 return "|"; 062 } 063}