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Drools Planner optimizes automated planning by combining metaheuristic search algorithms with rule
engine powered score calculation. This is the drools-planner-core module which contains metaheuristic
algorithms.
/*
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.planner.core.score.buildin.hardandsoft;
import org.drools.planner.core.score.Score;
import org.drools.planner.core.solution.Solution;
/**
* A HardAndSoftScore is a Score based on hard and soft int constraints.
* Hard constraints have priority over soft constraints.
*
* Implementations must be immutable.
* @see Score
* @see DefaultHardAndSoftScore
*/
public interface HardAndSoftScore extends Score {
/**
* The total of the broken negative hard constraints and fulfilled positive hard constraints.
* Their weight is included in the total.
* The hard score is usually a negative number because most use cases only have negative constraints.
* @return higher is better, usually negative, 0 if no hard constraints are broken/fulfilled
*/
int getHardScore();
/**
* The total of the broken negative soft constraints and fulfilled positive soft constraints.
* Their weight is included in the total.
* The soft score is usually a negative number because most use cases only have negative constraints.
*
* In a normal score comparison, the soft score is irrelevant if the 2 scores don't have the same hard score.
* @return higher is better, usually negative, 0 if no soft constraints are broken/fulfilled
*/
int getSoftScore();
/**
* A {@link Solution} is feasible if it has no broken hard constraints.
* @return true if the {@link #getHardScore()} is 0 or higher
*/
boolean isFeasible();
}