001/*
002 * Copyright (c) 2005 Einar Pehrson <einar@pehrson.nu>.
003 *
004 * This file is part of
005 * CleanSheets - a spreadsheet application for the Java platform.
006 *
007 * CleanSheets is free software; you can redistribute it and/or modify
008 * it under the terms of the GNU General Public License as published by
009 * the Free Software Foundation; either version 2 of the License, or
010 * (at your option) any later version.
011 *
012 * CleanSheets is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
015 * GNU General Public License for more details.
016 *
017 * You should have received a copy of the GNU General Public License
018 * along with CleanSheets; if not, write to the Free Software
019 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
020 */
021package csheets.core.formula.lang;
022
023import csheets.core.IllegalValueTypeException;
024import csheets.core.Value;
025import csheets.core.formula.BinaryOperator;
026import csheets.core.formula.Expression;
027
028/**
029 * A concatenator of strings.
030 * @author Einar Pehrson
031 */
032public class Concatenator implements BinaryOperator {
033
034        /** The unique version identifier used for serialization */
035        private static final long serialVersionUID = 4364553607579868067L;
036
037        /**
038         * Creates a new concatenator.
039         */
040        public Concatenator() {}
041
042        public Value applyTo(Expression leftOperand, Expression rightOperand) throws IllegalValueTypeException {
043                return new Value(
044                        leftOperand.evaluate().toText()
045                        +
046                        rightOperand.evaluate().toText()
047                );
048        }
049
050        public String getIdentifier() {
051                return "&";
052        }
053
054        public Value.Type getOperandValueType() {
055                return Value.Type.TEXT;
056        }
057
058        public String toString() {
059                return getIdentifier();
060        }
061}