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 **/
019/**
020 * Implements the CFML Function left
021 */
022package lucee.runtime.functions.string;
023
024import lucee.runtime.PageContext;
025import lucee.runtime.exp.ExpressionException;
026import lucee.runtime.exp.FunctionException;
027import lucee.runtime.exp.PageException;
028import lucee.runtime.functions.BIF;
029import lucee.runtime.op.Caster;
030
031public final class Left extends BIF {
032
033        private static final long serialVersionUID = 571667661130843970L;
034
035        public static String call(PageContext pc, String str, double number) throws ExpressionException {
036                int len = (int)number;
037                if (len == 0) throw new ExpressionException("parameter 2 of the function left can not be 0");
038                if (Math.abs(len) >= str.length()) return str;
039                if (len < 0) len = str.length() + len;
040                return str.substring(0,len);
041        }
042
043    @Override
044        public Object invoke(PageContext pc, Object[] args) throws PageException {
045                if(args.length==2)
046                        return call(pc, Caster.toString(args[0]), Caster.toDoubleValue(args[1]));
047                throw new FunctionException(pc, "Left", 2, 2, args.length);
048        }
049}