    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     */
    017    package org.apache.commons.jxpath.ri.compiler;
    018
    019    import org.apache.commons.jxpath.ri.EvalContext;
    020    import 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 12:46:46 -0500 (Fri, 02 May 2008) $
    027     */
    028    public 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    }