001/* 002// This software is subject to the terms of the Eclipse Public License v1.0 003// Agreement, available at the following URL: 004// http://www.eclipse.org/legal/epl-v10.html. 005// You must accept the terms of that agreement to use this software. 006// 007// Copyright (C) 2006-2006 Pentaho 008// All Rights Reserved. 009*/ 010package mondrian.calc; 011 012import mondrian.olap.Evaluator; 013 014/** 015 * Compiled expression whose result is a <code>boolean</code>. 016 * 017 * <p>When implementing this interface, it is convenient to extend 018 * {@link mondrian.calc.impl.AbstractBooleanCalc}, but it is not required. 019 * 020 * @author jhyde 021 * @since Sep 27, 2005 022 */ 023public interface BooleanCalc extends Calc { 024 /** 025 * Evaluates this expression to yield a <code>boolean</code> value. 026 * If the result is null, returns the special 027 * {@link mondrian.olap.fun.FunUtil#BooleanNull} value. 028 * 029 * @param evaluator Evaluation context 030 * @return evaluation result 031 */ 032 boolean evaluateBoolean(Evaluator evaluator); 033} 034 035// End BooleanCalc.java