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 csheets.core.IllegalValueTypeException;
024import csheets.core.Value;
025
026/**
027 * A unary operator in a formula.
028 * @author Einar Pehrson
029 */
030public interface UnaryOperator extends Operator {
031
032        /**
033         * Applies the operator to the given operand and returns the result.
034         * @return the result of the operation
035         * @throws IllegalValueTypeException if the value of the operand is not of the expected type
036         */
037        public Value applyTo(Expression operand) throws IllegalValueTypeException;
038
039        /**
040         * Returns whether the operator is a prefix operator, i.e. it appears
041         * before its operand.
042         * @return true for prefix operators, false for postfix operators
043         */
044        public boolean isPrefix();
045}