private FAState GetOptimalState(FAState sourceState, IEnumerable <FATransition> filterTransition, FiniteAutomata DFA)
{
FAState selectedState = null;
IEnumerable <FAState> finalStateFilter = filterTransition.SelectMany(x => x.ToState.Where(y => y.IsFinalState));
if (finalStateFilter.Count() == 1)
{
selectedState = finalStateFilter.First();
}
else
{
bool xLoop = filterTransition.All(x => x.FromState == sourceState &&
x.ToState.Any(y => y.StateName == sourceState.StateName) &&
x.FromState.IsFinalState);
if (xLoop)
{
string emptySName = "Empty";
FAState emptySet = new FAState(emptySName);
if (!DFA.States.Any(x => x.StateName == emptySet.StateName))
{
_ = DFA.AddState(emptySet);
foreach (char symbol in DFA.Alphabet)
{
_ = DFA.AddTransition(symbol, emptySName, emptySName);
}
}
selectedState = emptySet;
return(selectedState);
}
IEnumerable <FAState> selfRefStates = filterTransition.Where(x => x.ToState.Any(y => y == sourceState && x.FromState == sourceState) && !x.Direction)
.Select(x => x.FromState);
FAState selfRefSt = selfRefStates.FirstOrDefault();
if (selfRefSt != null)
{
FAState updState = new FAState(selfRefSt.StateName, selfRefSt.IsInitialState);
DFA.UpdateState(updState);
selectedState = updState;
return(selectedState);
}
IEnumerable <FAState> selfReferenceFilter = filterTransition.SelectMany(x => x.ToState.Where(y => y != sourceState));
if (selfReferenceFilter.Count() == 1)
{
selectedState = selfReferenceFilter.First();
}
else
{
selectedState = filterTransition.First().FromState;
}
}
return(selectedState);
}
public void Should_ReturnTrue_When_UpdateState_WithFAState()
{
List <char> alphabet = new List <char>()
{
'a'
};
FiniteAutomata automata = new FiniteAutomata(FiniteAutomataType.TwoWayDFA, alphabet);
FAState state = new FAState("State Name", isInitialState: true, isFinalState: true);
automata.AddState(state);
state = new FAState("State Name", isInitialState: true, isFinalState: false);
Assert.True(automata.UpdateState(state));
}