    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
    018package org.apache.commons.jxpath.ri.compiler;
    019
    020import org.apache.commons.jxpath.ri.EvalContext;
    021import org.apache.commons.jxpath.ri.axes.UnionContext;
    022
    023/**
    024 * Implementation of {@link Expression} for the operation "|".
    025 */
    026public class CoreOperationUnion extends CoreOperation {
    027
    028    /**
    029     * Constructs a new CoreOperationUnion.
    030     *
    031     * @param args Expression[]
    032     */
    033    public CoreOperationUnion(final Expression[] args) {
    034        super(args);
    035    }
    036
    037    @Override
    038    public Object computeValue(final EvalContext context) {
    039        final EvalContext[] argCtxs = new EvalContext[args.length];
    040        for (int i = 0; i < args.length; i++) {
    041            final Object value = args[i].compute(context);
    042            if (value instanceof EvalContext) {
    043                argCtxs[i] = (EvalContext) value;
    044            } else {
    045                argCtxs[i] = context.getRootContext().getConstantContext(value);
    046            }
    047        }
    048        return new UnionContext(context.getRootContext(), argCtxs);
    049    }
    050
    051    @Override
    052    protected int getPrecedence() {
    053        return UNION_PRECEDENCE;
    054    }
    055
    056    @Override
    057    public String getSymbol() {
    058        return "|";
    059    }
    060
    061    @Override
    062    protected boolean isSymmetric() {
    063        return true;
    064    }
    065}