/* *************************************************************************************** * Copyright (C) 2006 EsperTech, Inc. All rights reserved. * * http://www.espertech.com/esper * * http://www.espertech.com * * ---------------------------------------------------------------------------------- * * The software in this package is published under the terms of the GPL license * * a copy of which has been included with this distribution in the license.txt file. * *************************************************************************************** */ package com.espertech.esper.epl.expression.core; import com.espertech.esper.client.EventBean; /** * Interface for evaluating of an event tuple. */ public interface ExprEvaluator { /** * Evaluate event tuple and return result. * * @param eventsPerStream - event tuple * @param isNewData - indicates whether we are dealing with new data (istream) or old data (rstream) * @param context context for expression evaluation * @return evaluation result, a boolean value for OR/AND-type evalution nodes. */ public Object evaluate(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context); /** * Returns the type that the node's evaluate method returns an instance of. * * @return type returned when evaluated */ public Class getType(); }