ExecutionListener.java

/*
Copyright (c) 2008 Arno Haase.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html

Contributors:
    Arno Haase - initial API and implementation
 */
package org.eclipse.xtend.backend.common;


/**
 * This interface allows an interested party to register as a listener for the
 *  execution of code in the backend. The model is slightly different from the
 *  typical listener usage in that there are no "rich" events. Instead, just the
 *  current ExecutionContext is passed as a parameter.<br>
 *  
 * So there is no data that would allow the identification of the sender or a 
 *  specific receiver. The intended usage model is that the middle end registers
 *  a specific ExecutionListener instance per backend element that takes care of
 *  these mapping issues.  
 * 
 * @author Arno Haase (http://www.haase-consulting.com)
 */
public interface ExecutionListener {
    void preExecute (ExecutionContext ctx, ExpressionBase originator) throws EvaluationVetoException;
    void postExecute (Object result, ExecutionContext ctx, ExpressionBase originator);
}