Package de.learnlib.oracle.equivalence

Class AbstractTestWordEQOracle<A extends Output<I,D>,I,D>

java.lang.Object

de.learnlib.oracle.equivalence.AbstractTestWordEQOracle<A,I,D>

Type Parameters:

A - hypothesis type

I - input symbol type

D - output (domain) type

All Implemented Interfaces:

EquivalenceOracle<A,I,D>

Direct Known Subclasses:

CompleteExplorationEQOracle, IncrementalWMethodEQOracle, RandomWellMatchedWordsEQOracle, RandomWMethodEQOracle, RandomWordsEQOracle, RandomWpMethodEQOracle, WMethodEQOracle, WMethodEQOracle, WMethodEQOracle, WMethodEQOracle, WpMethodEQOracle, WpMethodEQOracle

public abstract class AbstractTestWordEQOracle<A extends Output<I,D>,I,D>
extends Object
implements EquivalenceOracle<A,I,D>

An abstract equivalence oracle that takes care of query batching and hypothesis checking and allows extending classes to solely focus on test word generation by implementing generateTestWords(Output, Collection).

Being stream-based, this oracle encourages the lazy computation of counterexamples, so that all counterexamples do not have to be computed upfront, but only until the first valid counterexample is found.

Nested Class Summary

Nested classes/interfaces inherited from interface de.learnlib.oracle.EquivalenceOracle

EquivalenceOracle.DFAEquivalenceOracle<I>, EquivalenceOracle.MealyEquivalenceOracle<I,O>, EquivalenceOracle.MooreEquivalenceOracle<I,O>

Constructor Summary

Constructors

Constructor	Description
AbstractTestWordEQOracle(MembershipOracle<I,D> membershipOracle)
AbstractTestWordEQOracle(MembershipOracle<I,D> membershipOracle, int batchSize)

Method Summary

Modifier and Type	Method	Description
@Nullable DefaultQuery<I,D>	findCounterExample(A hypothesis, Collection<? extends I> inputs)	Searches for a counterexample disproving the subjected hypothesis.
protected abstract Stream<Word<I>>	generateTestWords(A hypothesis, Collection<? extends I> inputs)	Generate the stream of test words that should be used for the current equivalence check cycle.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractTestWordEQOracle

public AbstractTestWordEQOracle(MembershipOracle<I,D> membershipOracle)

AbstractTestWordEQOracle

public AbstractTestWordEQOracle(MembershipOracle<I,D> membershipOracle,
                                int batchSize)

Method Detail

findCounterExample

public @Nullable DefaultQuery<I,D> findCounterExample(A hypothesis,
                                                            Collection<? extends I> inputs)

Description copied from interface: EquivalenceOracle

Searches for a counterexample disproving the subjected hypothesis. A counterexample is query which, when performed on the SUL, yields a different output than what was predicted by the hypothesis. If no counterexample could be found (this does not necessarily mean that none exists), null is returned.

Specified by:

findCounterExample in interface EquivalenceOracle<A extends Output<I,D>,I,D>

Parameters:

hypothesis - the conjecture

inputs - the set of inputs to consider, this should be a subset of the input alphabet of the provided hypothesis

Returns:

a query exposing different behavior, or null if no counterexample could be found. In case a non-null value is returned, the output field in the DefaultQuery contains the SUL output for the respective query.

generateTestWords

protected abstract Stream<Word<I>> generateTestWords(A hypothesis,
                                                     Collection<? extends I> inputs)

Generate the stream of test words that should be used for the current equivalence check cycle.

Parameters:

hypothesis - the current hypothesis of the learning algorithm

inputs - the collection of inputs to consider

Returns:

the stream of test words used for equivalence testing

See Also:

EquivalenceOracle.findCounterExample(Object, Collection)