org.openl.ie.constrainer.GoalAnd Maven / Gradle / Ivy
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package org.openl.ie.constrainer;
///////////////////////////////////////////////////////////////////////////////
/*
* Copyright Exigen Group 1998, 1999, 2000
* 320 Amboy Ave., Metuchen, NJ, 08840, USA, www.exigengroup.com
*
* The copyright to the computer program(s) herein
* is the property of Exigen Group, USA. All rights reserved.
* The program(s) may be used and/or copied only with
* the written permission of Exigen Group
* or in accordance with the terms and conditions
* stipulated in the agreement/contract under which
* the program(s) have been supplied.
*/
///////////////////////////////////////////////////////////////////////////////
/**
* A goal can be defined in terms of it's subgoals. Class GoalAnd makes it possible to create a goal
* composed of a sequence (up to six) of other goals. To overcome the restriction of six goals imposed by it's
* constructors one can use the following trick: let's assume the goalsArray to be an array of goals
*
*
* Goal tempGoal = new GoalAnd(goalsArray.get(0),goalsArray.get(1));
* for (int i = 2; i < goalsArray.size(); i++){
* tempGoal = new GoalAnd(tempGoal, goalsArray.get(i));
* }
*
*
* GoalAnd pushes all it's subgoals to the execution stack. It succeeds if and only if all it's subgoals succeed. In
* that case it returns null otherwise it generates an exception of type Failure.
*/
public class GoalAnd extends GoalImpl {
private final Goal _g1;
private final Goal _g2;
/**
* Constructor of two arguments
*/
public GoalAnd(Goal g1, Goal g2) {
super(g1.constrainer(), "");// "{"+g1.name()+"&&"+g2.name()+"}");
_g1 = g1;
_g2 = g2;
}
/**
* Executes this goal.
*
* @return Null if succeeds
* @throws Failure if one of it's subgoals fails
*/
@Override
public Goal execute() throws Failure {
// Debug.print("Execute "+this);
constrainer().pushOnExecutionStack(_g2);
constrainer().pushOnExecutionStack(_g1);
return null;
}
@Override
public String toString() {
return "{" + _g1 + "&&" + _g2 + "}";
}
}