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    }