/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.taglibs.standard.lang.jstl;

/**
 * <p>The implementation of the less than operator
 *
 * @author Nathan Abramson - Art Technology Group
 */

public class LessThanOperator
        extends RelationalOperator {
    //-------------------------------------
    // Singleton
    //-------------------------------------

    public static final LessThanOperator SINGLETON =
            new LessThanOperator();

    //-------------------------------------

    /**
     * Constructor
     */
    public LessThanOperator() {
    }

    //-------------------------------------
    // Expression methods
    //-------------------------------------

    /**
     * Returns the symbol representing the operator
     */
    public String getOperatorSymbol() {
        return "<";
    }

    //-------------------------------------

    /**
     * Applies the operator to the given value
     */
    public Object apply(Object pLeft,
                        Object pRight,
                        Object pContext,
                        Logger pLogger)
            throws ELException {
        if (pLeft == pRight) {
            return Boolean.FALSE;
        } else if (pLeft == null ||
                pRight == null) {
            return Boolean.FALSE;
        } else {
            return super.apply(pLeft, pRight, pContext, pLogger);
        }
    }

    //-------------------------------------

    /**
     * Applies the operator to the given double values
     */
    public boolean apply(double pLeft,
                         double pRight,
                         Logger pLogger) {
        return pLeft < pRight;
    }

    //-------------------------------------

    /**
     * Applies the operator to the given long values
     */
    public boolean apply(long pLeft,
                         long pRight,
                         Logger pLogger) {
        return pLeft < pRight;
    }

    //-------------------------------------

    /**
     * Applies the operator to the given String values
     */
    public boolean apply(String pLeft,
                         String pRight,
                         Logger pLogger) {
        return pLeft.compareTo(pRight) < 0;
    }

    //-------------------------------------
}
