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Complex event processing and event series analysis component

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/**************************************************************************************
 * Copyright (C) 2008 EsperTech, Inc. All rights reserved.                            *
 * http://esper.codehaus.org                                                          *
 * 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;

/**
 * Visitor interface for use with expression node trees, receives both the child node and the parent node (or null to indicate no parent node).
 */
public interface ExprNodeVisitorWithParent
{
    /**
     * Allows visitor to indicate whether to visit a given node.
     * Implicitly if a visitor doesn't visit a node it would also not visit any descendent child nodes of that node.
     * @param exprNode is the node in questions
     * @return true if the visitor wants to visit the child node (next call is visit), or false to skip child
     */
    public boolean isVisit(ExprNode exprNode);

    /**
     * Visit the given expression node.
     * @param exprNode is the expression node to visit
     * @param parentExprNode parent to visit
     */
    public void visit(ExprNode exprNode, ExprNode parentExprNode);
}