private List<State> epsilonClosure(State state) {
List<State> epsilonStates = new LinkedList<State>();
List<State> temporaryStates = new LinkedList<State>();
List<State> pStates = new LinkedList<State>();
boolean added;
epsilonStates.add(state);
do {
added = false;
for (State someState : epsilonStates) {
List<OutgoingTransition> someStateTransitions =
new LinkedList<OutgoingTransition>(automaton.allOutgoingTransitions(someState));
for (OutgoingTransition transition : someStateTransitions) {
if (transition.getTransitionLabel().canBeEpsilon()
&& !temporaryStates.contains(transition.getTargetState())) {
temporaryStates.add(transition.getTargetState());
}
}
for (State tState : temporaryStates) {
if (!epsilonStates.contains(tState) && !pStates.contains(tState)) {
pStates.add(tState);
added = true;
}
}
temporaryStates.clear();
}
epsilonStates.addAll(pStates);
pStates.clear();
} while (added);
return epsilonStates;
}
/**
* Metoda, która będzie wywoływana rekurencyjnie dla aktualnych stanów, pobiera wszystkie
* przejscia z bieżącego stanu, porównuje ich etykiety ze znakiem (tzn.characters.charAt(from)) z
* wprowadzonego napisu, jeśli sie zgadzają, porównuje stan docelowy przejścia.
*/
private void check(String text, int from, int toEnd, State state) {
if (from > toEnd) {
if (automaton.isFinal(state)) {
accept = true;
}
} else {
List<OutgoingTransition> allOutTransitions;
allOutTransitions = automaton.allOutgoingTransitions(state);
if (!allOutTransitions.isEmpty()) {
for (OutgoingTransition transition : allOutTransitions) {
TransitionLabel currentLabel = transition.getTransitionLabel();
if (currentLabel.canBeEpsilon()) {
throw new RuntimeException();
}
if (currentLabel.canAcceptCharacter(text.charAt(from))) {
check(text, from + 1, toEnd, transition.getTargetState());
}
if (accept) {
return;
}
}
}
}
}
@Override
public boolean accepts(final String text) {
accept = false;
int i = 0;
int limit = text.length();
boolean added;
currentStates = new LinkedList<State>();
List<State> temporaryStates = new LinkedList<State>();
List<State> pStates = new LinkedList<State>();
currentStates.add(automaton.getInitialState());
do {
do {
added = false;
for (State someState : currentStates) {
List<State> epsilonStates = new LinkedList<State>(epsilonClosure(someState));
for (State eState : epsilonStates) {
if (!currentStates.contains(eState) && !pStates.contains(eState)) {
pStates.add(eState);
added = true;
}
}
}
currentStates.addAll(pStates);
pStates.clear();
} while (added);
if (limit != 0 && i != limit) {
for (State someState : currentStates) {
List<OutgoingTransition> someStateTransitions =
new LinkedList<OutgoingTransition>(automaton.allOutgoingTransitions(someState));
for (OutgoingTransition transition : someStateTransitions) {
if (transition.getTransitionLabel().canAcceptCharacter(text.charAt(i))
&& !temporaryStates.contains(transition.getTargetState())) {
temporaryStates.add(transition.getTargetState());
}
}
}
currentStates.clear();
currentStates.addAll(temporaryStates);
temporaryStates.clear();
}
i++;
} while (i <= limit);
for (State someState : currentStates) {
if (automaton.isFinal(someState)) {
accept = true;
}
}
return accept;
}
