/*
***************************************************************************************
* 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.pattern.guard;
import com.espertech.esper.pattern.MatchedEventMap;
/**
* Guard instances inspect a matched events and makes a determination on whether to let it pass or not.
*/
public interface Guard {
/**
* Start the guard operation.
*/
public void startGuard();
/**
* Called when sub-expression quits, or when the pattern stopped.
*/
public void stopGuard();
/**
* Returns true if inspection shows that the match events can pass, or false to not pass.
*
* @param matchEvent is the map of matching events
* @return true to pass, false to not pass
*/
public boolean inspect(MatchedEventMap matchEvent);
public void accept(EventGuardVisitor visitor);
}