001/**
002 *
003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either 
008 * version 2.1 of the License, or (at your option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013 * Lesser General Public License for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public 
016 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
017 * 
018 **/
019package lucee.runtime.type;
020
021import lucee.runtime.PageContext;
022import lucee.runtime.dump.DumpData;
023import lucee.runtime.dump.DumpProperties;
024import lucee.runtime.dump.DumpUtil;
025import lucee.runtime.dump.Dumpable;
026import lucee.runtime.exp.ExpressionException;
027import lucee.runtime.exp.PageException;
028import lucee.runtime.op.Castable;
029import lucee.runtime.type.dt.DateTime;
030
031/**
032 * Custom Null Type
033 */
034public final class Null implements Castable,Dumpable {
035    public static final Null NULL=new Null();
036    private Null() {}
037    
038    @Override
039    public String castToString() throws ExpressionException {
040        return "";
041    }
042
043        @Override
044        public String castToString(String defaultValue) {
045                return "";
046        }
047        
048    @Override
049    public boolean castToBooleanValue() throws ExpressionException {
050        throw new ExpressionException("can't convert null to a boolean");
051    }
052    
053    @Override
054    public Boolean castToBoolean(Boolean defaultValue) {
055        return defaultValue;
056    }
057    
058    @Override
059    public double castToDoubleValue() throws ExpressionException {
060        throw new ExpressionException("can't convert null to a numberic value");
061    }
062    
063    @Override
064    public double castToDoubleValue(double defaultValue) {
065        return defaultValue;
066    }
067    
068    @Override
069    public DateTime castToDateTime() throws ExpressionException {
070        throw new ExpressionException("can't convert null to a date object");
071    }
072    
073    @Override
074    public DateTime castToDateTime(DateTime defaultValue) {
075        return defaultValue;
076    }
077    
078    @Override
079    public DumpData toDumpData(PageContext pageContext, int maxlevel, DumpProperties dp) {
080        return DumpUtil.toDumpData(null,pageContext,maxlevel,dp);
081    }
082    @Override
083    public String toString() {
084        return null;
085    }
086        public int compareTo(String str) throws PageException {
087                return "".compareTo(str);
088        //throw new ExpressionException("can't compare null with a string value");
089        }
090        public int compareTo(boolean b) throws PageException {
091        throw new ExpressionException("can't compare null with a boolean value");
092        }
093        public int compareTo(double d) throws PageException {
094        throw new ExpressionException("can't compare null with a numeric value");
095        }
096        public int compareTo(DateTime dt) throws PageException {
097        throw new ExpressionException("can't compare null with a date object");
098        }
099}