    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.InfoSetUtil;
    021
    022    /**
    023     * A compile tree element containing a constant number or string.
    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 Constant extends Expression {
    029
    030        private Object value;
    031
    032        /**
    033         * Create a new Constant.
    034         * @param number constant
    035         */
    036        public Constant(Number number) {
    037            this.value = number;
    038        }
    039
    040        /**
    041         * Create a new Constant.
    042         * @param string constant
    043         */
    044        public Constant(String string) {
    045            this.value = string;
    046        }
    047
    048        public Object compute(EvalContext context) {
    049            return value;
    050        }
    051
    052        public Object computeValue(EvalContext context) {
    053            return value;
    054        }
    055
    056        /**
    057         * Returns false
    058         * @return false
    059         */
    060        public boolean isContextDependent() {
    061            return false;
    062        }
    063
    064        /**
    065         * Returns false
    066         * @return false
    067         */
    068        public boolean computeContextDependent() {
    069            return false;
    070        }
    071
    072        public String toString() {
    073            if (value instanceof Number) {
    074                return InfoSetUtil.stringValue(value);
    075            }
    076            return "'" + value + "'";
    077        }
    078    }