de.learnlib.algorithms.ttt.base

Class BaseTTTLearner<A,I,D>

java.lang.Object

de.learnlib.algorithms.ttt.base.BaseTTTLearner<A,I,D>

Type Parameters:

I - input symbol type

All Implemented Interfaces:

AccessSequenceTransformer<I>, LearningAlgorithm<A,I,D>, Output<I,D>, SuffixOutput<I,D>

Direct Known Subclasses:

TTTLearnerDFA, TTTLearnerMealy

public abstract class BaseTTTLearner<A,I,D>
extends Object
implements LearningAlgorithm<A,I,D>, AccessSequenceTransformer<I>, SuffixOutput<I,D>

The TTT learning algorithm for DFA.

Author:

Malte Isberner

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BaseTTTLearner.BuilderDefaults
static class	BaseTTTLearner.Splitter<I,D> Data structure for representing a splitter.

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

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

Field Summary

Fields

Modifier and Type	Field and Description
protected Alphabet<I>	alphabet
protected BlockList<I,D>	blockList The blocks during a split operation.
protected DiscriminationTree<I,D>	dtree
protected TTTHypothesis<I,D,?>	hypothesis

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseTTTLearner(Alphabet<I> alphabet, MembershipOracle<I,D> oracle, TTTHypothesis<I,D,?> hypothesis, LocalSuffixFinder<? super I,? super D> suffixFinder)

Method Summary

Modifier and Type	Method and Description
void	addEventListener(TTTEventListener<I,D> listener)
protected DTNode<I,D>	chooseInnerNode(DTNode<I,D> root)
protected DTNode<I,D>	chooseLeaf(DTNode<I,D> root)
protected abstract D	computeHypothesisOutput(TTTState<I,D> state, Iterable<? extends I> suffix)
D	computeOutput(Iterable<? extends I> input)
D	computeSuffixOutput(Iterable<? extends I> prefix, Iterable<? extends I> suffix)
protected <V> Map<D,V>	createMap()
protected TTTTransition<I,D>	createTransition(TTTState<I,D> state, I sym)
protected void	declareFinal(DTNode<I,D> blockRoot)
DiscriminationTree.GraphView	dtGraphView()
protected boolean	finalizeAny() Chooses a block root, and finalizes the corresponding discriminator.
DiscriminationTree<I,D>	getDiscriminationTree() Returns the discrimination tree.
GraphDOTHelper<TTTState<I,D>,TTTHypothesis.TTTEdge<I,D>>	getHypothesisDOTHelper()
TTTHypothesis<I,D,?>	getHypothesisDS()
protected TTTState<I,D>	getState(TTTState<I,D> start, Iterable<? extends I> suffix) Retrieves the successor for a given state and a suffix sequence.
protected TTTState<I,D>	getTarget(TTTTransition<I,D> trans) Retrieves the target state of a given transition.
protected void	initializeState(TTTState<I,D> state) Initializes a state.
boolean	isAccessSequence(Word<I> word)
protected D	predictSuccOutcome(TTTTransition<I,D> trans, DTNode<I,D> succSeparator)
protected D	query(AccessSequenceProvider<I> accessSeqProvider, Word<I> suffix) Performs a membership query, using an access sequence as its prefix.
protected D	query(Word<I> prefix, Word<I> suffix) Performs a membership query.
boolean	refineHypothesis(DefaultQuery<I,D> ceQuery)
void	removeEventListener(TTTEventListener<I,D> listener)
protected DTNode<I,D>[]	split(DTNode<I,D> node, Word<I> discriminator, D... outputs)
void	startLearning()
Word<I>	transformAccessSequence(Word<I> word)

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.learnlib.api.LearningAlgorithm

getHypothesisModel

Field Detail

alphabet

protected final Alphabet<I> alphabet

hypothesis

protected final TTTHypothesis<I,D,?> hypothesis

dtree

protected final DiscriminationTree<I,D> dtree

blockList

protected final BlockList<I,D> blockList

The blocks during a split operation. A block is a maximal subtree of the discrimination tree containing temporary discriminators at its root.

Constructor Detail

BaseTTTLearner

protected BaseTTTLearner(Alphabet<I> alphabet,
                         MembershipOracle<I,D> oracle,
                         TTTHypothesis<I,D,?> hypothesis,
                         LocalSuffixFinder<? super I,? super D> suffixFinder)

Method Detail

startLearning

public void startLearning()

Specified by:

startLearning in interface LearningAlgorithm<A,I,D>

refineHypothesis

public boolean refineHypothesis(DefaultQuery<I,D> ceQuery)

Specified by:

refineHypothesis in interface LearningAlgorithm<A,I,D>

initializeState

protected void initializeState(TTTState<I,D> state)

Initializes a state. Creates its outgoing transition objects, and adds them to the "open" list.

Parameters:

state - the state to initialize

createTransition

protected TTTTransition<I,D> createTransition(TTTState<I,D> state,
                                              I sym)

finalizeAny

protected boolean finalizeAny()

Chooses a block root, and finalizes the corresponding discriminator.

Returns:

true if a splittable block root was found, false otherwise.

chooseInnerNode

protected DTNode<I,D> chooseInnerNode(DTNode<I,D> root)

chooseLeaf

protected DTNode<I,D> chooseLeaf(DTNode<I,D> root)

getTarget

protected TTTState<I,D> getTarget(TTTTransition<I,D> trans)

Retrieves the target state of a given transition. This method works for both tree and non-tree transitions. If a non-tree transition points to a non-leaf node, it is updated accordingly before a result is obtained.

Parameters:

trans - the transition

Returns:

the target state of this transition (possibly after it having been updated)

getState

protected TTTState<I,D> getState(TTTState<I,D> start,
                                 Iterable<? extends I> suffix)

Retrieves the successor for a given state and a suffix sequence.

Parameters:

start - the originating state

suffix - the sequence of input symbols to process

Returns:

the state reached after processing suffix, starting from start

declareFinal

protected void declareFinal(DTNode<I,D> blockRoot)

predictSuccOutcome

protected D predictSuccOutcome(TTTTransition<I,D> trans,
                               DTNode<I,D> succSeparator)

createMap

protected <V> Map<D,V> createMap()

computeHypothesisOutput

protected abstract D computeHypothesisOutput(TTTState<I,D> state,
                                             Iterable<? extends I> suffix)

computeOutput

public D computeOutput(Iterable<? extends I> input)

Specified by:

computeOutput in interface Output<I,D>

Specified by:

computeOutput in interface SuffixOutput<I,D>

computeSuffixOutput

public D computeSuffixOutput(Iterable<? extends I> prefix,
                             Iterable<? extends I> suffix)

Specified by:

computeSuffixOutput in interface SuffixOutput<I,D>

transformAccessSequence

public Word<I> transformAccessSequence(Word<I> word)

Specified by:

transformAccessSequence in interface AccessSequenceTransformer<I>

isAccessSequence

public boolean isAccessSequence(Word<I> word)

Specified by:

isAccessSequence in interface AccessSequenceTransformer<I>

getHypothesisDS

public TTTHypothesis<I,D,?> getHypothesisDS()

dtGraphView

public DiscriminationTree.GraphView dtGraphView()

getHypothesisDOTHelper

public GraphDOTHelper<TTTState<I,D>,TTTHypothesis.TTTEdge<I,D>> getHypothesisDOTHelper()

query

protected D query(Word<I> prefix,
                  Word<I> suffix)

Performs a membership query.

Parameters:

prefix - the prefix part of the query

suffix - the suffix part of the query

Returns:

the output

query

protected D query(AccessSequenceProvider<I> accessSeqProvider,
                  Word<I> suffix)

Performs a membership query, using an access sequence as its prefix.

Parameters:

accessSeqProvider - the object from which to obtain the access sequence

suffix - the suffix part of the query

Returns:

the output

getDiscriminationTree

public DiscriminationTree<I,D> getDiscriminationTree()

Returns the discrimination tree.

Returns:

the discrimination tree

split

@SafeVarargs
protected final DTNode<I,D>[] split(DTNode<I,D> node,
                                                 Word<I> discriminator,
                                                 D... outputs)

addEventListener

public void addEventListener(TTTEventListener<I,D> listener)

removeEventListener

public void removeEventListener(TTTEventListener<I,D> listener)