InferenceLog.java

package aima.core.search.csp.inference;

import aima.core.search.csp.CSP;
import aima.core.search.csp.Variable;

/**
 * Provides information about (1) whether changes have been performed, (2) possibly inferred empty domains , and
 * (3) how to restore the CSP.
 *
 * @author Ruediger Lunde
 */
public interface InferenceLog<VAR extends Variable, VAL> {
    boolean isEmpty();
    boolean inconsistencyFound();
    void undo(CSP<VAR, VAL> csp);

    /**
     * Returns an empty inference log.
     * @author Ruediger Lunde
     */
    static <VAR extends Variable, VAL> InferenceLog<VAR, VAL> emptyLog() {
        return new InferenceLog<VAR, VAL>() {
            @Override
            public boolean isEmpty () { return true; }

            @Override
            public boolean inconsistencyFound () { return false; }

            @Override
            public void undo (CSP<VAR, VAL> csp){ }
        };
    }
}