de.learnlib.algorithms.baselinelstar

Class BaselineLStar<I>

java.lang.Object

de.learnlib.algorithms.baselinelstar.BaselineLStar<I>

Type Parameters:

I - input symbol class.

All Implemented Interfaces:

GlobalSuffixFeature<I>, GlobalSuffixLearner<DFA<?,I>,I,Boolean>, GlobalSuffixLearner.GlobalSuffixLearnerDFA<I>, ObservationTableFeature<I,Boolean>, OTLearner<DFA<?,I>,I,Boolean>, LearningAlgorithm<DFA<?,I>,I,Boolean>

public class BaselineLStar<I>
extends Object
implements OTLearner<DFA<?,I>,I,Boolean>, GlobalSuffixLearner.GlobalSuffixLearnerDFA<I>

Implementation of the L* algorithm by Dana Angluin

Nested Class Summary

Nested classes/interfaces inherited from interface de.learnlib.algorithms.features.observationtable.OTLearner

OTLearner.OTLearnerDFA<I>, OTLearner.OTLearnerMealy<I,O>

Nested classes/interfaces inherited from interface de.learnlib.algorithms.features.globalsuffixes.GlobalSuffixLearner

GlobalSuffixLearner.GlobalSuffixLearnerDFA<I>, GlobalSuffixLearner.GlobalSuffixLearnerMealy<I,O>

Nested classes/interfaces inherited from interface de.learnlib.api.LearningAlgorithm

LearningAlgorithm.DFALearner<I>, LearningAlgorithm.MealyLearner<I,O>

Constructor Summary

Constructors

Constructor and Description
BaselineLStar(Alphabet<I> alphabet, MembershipOracle<I,Boolean> oracle) Initializes a newly created baseline L* implementation.

Method Summary

Modifier and Type	Method and Description
boolean	addGlobalSuffixes(Collection<? extends Word<I>> newGlobalSuffixes) Add the provided suffixes to the collection of global suffixes.
Collection<? extends Word<I>>	getGlobalSuffixes() Retrieves the global suffixes of this learner.
DFA<?,I>	getHypothesisModel() Returns the current hypothesis model.
ObservationTable<I,Boolean>	getObservationTable()
String	getStringRepresentationOfObservationTable()
boolean	refineHypothesis(DefaultQuery<I,Boolean> ceQuery) Triggers a refinement of the model by providing a counterexample.
void	startLearning() Starts the model inference process, creating an initial hypothesis in the provided model object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BaselineLStar

public BaselineLStar(@Nonnull
                     Alphabet<I> alphabet,
                     @Nonnull
                     MembershipOracle<I,Boolean> oracle)

Initializes a newly created baseline L* implementation. After this, the method startLearning() may be called once.

Parameters:

alphabet - The Alphabet to learn.

oracle - The MembershipOracle which is used for membership queries.

Method Detail

startLearning

public void startLearning()

Description copied from interface: LearningAlgorithm

Starts the model inference process, creating an initial hypothesis in the provided model object. Please note that it should be illegal to invoke this method twice.

Specified by:

startLearning in interface LearningAlgorithm<DFA<?,I>,I,Boolean>

refineHypothesis

public boolean refineHypothesis(@Nonnull
                                DefaultQuery<I,Boolean> ceQuery)

Description copied from interface: LearningAlgorithm

Triggers a refinement of the model by providing a counterexample. A counterexample is a query which exposes different behavior of the real SUL compared to the hypothesis. Please note that invoking this method before an initial invocation of LearningAlgorithm.startLearning() should be illegal.

Specified by:

refineHypothesis in interface LearningAlgorithm<DFA<?,I>,I,Boolean>

Parameters:

ceQuery - the query which exposes diverging behavior, as posed to the real SUL (i.e. with the SULs output).

Returns:

true if the counterexample triggered a refinement of the hypothesis, false otherwise (i.e., it was no counterexample).

getHypothesisModel

public DFA<?,I> getHypothesisModel()

Description copied from interface: LearningAlgorithm

Returns the current hypothesis model.

N.B.: By the contract of this interface, the model returned by this method may not be modified (i.e., M generally should refer to an immutable interface), and its validity is retained only until the next invocation of LearningAlgorithm.refineHypothesis(DefaultQuery). If older hypotheses have to be maintained, a copy of the returned model must be made.

Please note that it should be illegal to invoke this method before an initial invocation of LearningAlgorithm.startLearning().

Specified by:

getHypothesisModel in interface LearningAlgorithm<DFA<?,I>,I,Boolean>

Returns:

the current hypothesis model.

getStringRepresentationOfObservationTable

@Nonnull
public String getStringRepresentationOfObservationTable()

getGlobalSuffixes

@Nonnull
public Collection<? extends Word<I>> getGlobalSuffixes()

Description copied from interface: GlobalSuffixFeature

Retrieves the global suffixes of this learner. Calling this method before LearningAlgorithm.startLearning() should return an empty collection.

The return value should not be modified; attempting to do so may result in an UnsupportedOperationException. It is the implementation's responsibility to ensure attempted modifications do not corrupt the learner's internal state.

Specified by:

getGlobalSuffixes in interface GlobalSuffixFeature<I>

Returns:

the global suffixes used by this algorithm

addGlobalSuffixes

public boolean addGlobalSuffixes(@Nonnull
                                 Collection<? extends Word<I>> newGlobalSuffixes)

Description copied from interface: GlobalSuffixFeature

Add the provided suffixes to the collection of global suffixes. As this method is designed to possibly trigger a refinement, it is illegal to invoke it before LearningAlgorithm.startLearning() has been called.

The implementation may choose to (but is not required to) omit suffixes which are already present (that is, manage the global suffixes as a proper set).

Specified by:

addGlobalSuffixes in interface GlobalSuffixFeature<I>

Parameters:

newGlobalSuffixes - the global suffixes to add

Returns:

true if a refinement was triggered by adding the global suffixes, false otherwise.

getObservationTable

@Nonnull
public ObservationTable<I,Boolean> getObservationTable()

Specified by:

getObservationTable in interface ObservationTableFeature<I,Boolean>