/*******************************************************************************
* Copyright (c) 2005, 2007 IBM Corporation and others.
* 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
*
*******************************************************************************/
package org.eclipse.dltk.ti.goals;
import org.eclipse.dltk.ti.GoalState;
/**
* Abstract goal evaluator.
*/
public abstract class GoalEvaluator {
protected final IGoal goal;
public GoalEvaluator(IGoal goal) {
this.goal = goal;
}
public IGoal getGoal() {
return goal;
}
/**
* Called first time to fetch primary subgoals.
*
* @return array of required subgoals or <code>IGoal.NO_GOALS</code>
*/
public abstract IGoal[] init();
/**
* Called when some subgoal are done.
*
* @param subgoal
* completed subgoal
* @param result
* result of that subgoal
* @param state
* final state of subgoal (DONE, PRUNED or RECURSION)
* @return array of new required subgoals or <code>IGoal.NO_GOALS</code>
*/
public abstract IGoal[] subGoalDone(IGoal subgoal, Object result,
GoalState state);
/**
* Called when all posted subgoals are done
*
* @return result of evaluation this goal
*/
public abstract Object produceResult();
}