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; 022 023import java.io.Serializable; 024 025import csheets.core.Value; 026 027/** 028 * An operator in a formula. 029 * @author Einar Pehrson 030 */ 031public interface Operator extends Serializable { 032 033 /** 034 * Returns the operator's string identirifer. 035 * @return a string representation of the operator. 036 */ 037 public String getIdentifier(); 038 039 /** 040 * Returns the type of value that the operator's operands can have. 041 * @return the type of value that the operator's operands can have 042 */ 043 public Value.Type getOperandValueType(); 044}