de.learnlib.algorithms.adt.model.ExtensionResult Maven / Gradle / Ivy
/* Copyright (C) 2013-2018 TU Dortmund
* This file is part of LearnLib, http://www.learnlib.de/.
*
* 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 de.learnlib.algorithms.adt.model;
import javax.annotation.ParametersAreNonnullByDefault;
import de.learnlib.algorithms.adt.adt.ADTNode;
import de.learnlib.algorithms.adt.api.ADTExtender;
import de.learnlib.api.query.DefaultQuery;
import net.automatalib.words.Word;
/**
* A class that describes the possible result a {@link ADTExtender} can return. Extending a parent trace can either
* - yield a counterexample, if the output of the parent trace does not match the output of the hypothesis states of
* the leaves
- yield a valid replacement for the temporary splitter
- yield no result, if the
* referenced hypothesis states cannot be distinguished by means of extending the parent trace
*
* @param
* (hypothesis) state type
* @param
* input alphabet type
* @param
* output alphabet type
*
* @author frohme
*/
@ParametersAreNonnullByDefault
public class ExtensionResult {
private static final ExtensionResult EMPTY = new ExtensionResult();
private final DefaultQuery> counterExample;
private final ADTNode replacement;
private ExtensionResult() {
this.replacement = null;
this.counterExample = null;
}
public ExtensionResult(final ADTNode ext) {
this.replacement = ext;
this.counterExample = null;
}
public ExtensionResult(final DefaultQuery> ce) {
this.replacement = null;
this.counterExample = ce;
}
/**
* Utility method, returning the (singleton) object indicating, no result could be computed.
*
* @param
* (hypothesis) state type
* @param
* input alphabet type
* @param
* output alphabet type
*
* @return the empty result
*/
@SuppressWarnings("unchecked")
public static ExtensionResult empty() {
return (ExtensionResult) EMPTY;
}
/**
* Utility method, indicating the search for an extension has revealed a counterexample.
*
* @return {@code true} if a counter example was found, {@code false} otherwise
*/
public boolean isCounterExample() {
return this.counterExample != null;
}
/**
* Return the found counterexample.
*
* @return the counterexample
*/
public DefaultQuery> getCounterExample() {
return counterExample;
}
/**
* Utility method, indicating if the search for an extending replacement was a success.
*
* @return {@code true} if a replacement was found, {@code false} otherwise
*/
public boolean isReplacement() {
return this.replacement != null;
}
/**
* Return the proposed replacement.
*
* @return the replacement
*/
public ADTNode getReplacement() {
return replacement;
}
}