public void PushBack(State state)
{
_states.PushBack(state);
}
public void PushFront(State state)
{
_states.PushFront(state);
}
public PatternState()
{
_state = null;
_startIndex = -1;
}
public PatternState(PatternState other)
{
_state = other.State;
_startIndex = other.StateIndex;
}
public void AddTransition(char input, State destination)
{
if (!_destinations.ContainsKey(input))
_destinations[input] = new List<State>();
_destinations[input].Add(destination);
}
//A|B
private bool Union()
{
if (_operandStack.Count < 2)
return false;
FiniteStateAutomaton B = Pop();
FiniteStateAutomaton A = Pop();
var startState = new State(++_nextStateId);
var endState = new State(++_nextStateId);
startState.AddTransition(EPSILON, A.GetFirstState());
startState.AddTransition(EPSILON, B.GetFirstState());
A.GetLastState().AddTransition(EPSILON, endState);
B.GetLastState().AddTransition(EPSILON, endState);
A.PushFront(startState);
foreach (var item in B.GetStates())
{
A.PushBack(item);
}
A.PushBack(endState);
_operandStack.Push(A);
return true;
}
//Kleen A*
//
private bool Star()
{
if (_operandStack.Count < 1)
return false;
FiniteStateAutomaton A = Pop();
var startState = new State(++_nextStateId);
var endState = new State(++_nextStateId);
startState.AddTransition(EPSILON, endState);
startState.AddTransition(EPSILON, A.GetFirstState());
A.GetLastState().AddTransition(EPSILON, endState);
A.GetLastState().AddTransition(EPSILON, A.GetFirstState());
A.PushBack(endState);
A.PushFront(startState);
_operandStack.Push(A);
return true;
}
private void Push(Char input)
{
var state0 = new State(++_nextStateId);
var state1 = new State(++_nextStateId);
state0.AddTransition(input, state1);
FiniteStateAutomaton fsa = new FiniteStateAutomaton();
fsa.PushBack(state0);
fsa.PushBack(state1);
_operandStack.Push(fsa);
_inputSet.Add(input);
}
private void ConvertNFAToDFA()
{
if (_NFA == null)
return;
if (_DFA == null)
_DFA = new FiniteStateAutomaton();
_nextStateId = 0;
Stack<State> unmarkedStates = new Stack<State>();
HashSet<State> DFAStartStateSet = new HashSet<State>();
HashSet<State> NFAStartStateSet = new HashSet<State>();
NFAStartStateSet.Add(_NFA.GetFirstState());
DFAStartStateSet = EpsilonClosure(NFAStartStateSet);
var DFAStartState = new State(++_nextStateId, DFAStartStateSet);
_DFA.PushBack(DFAStartState);
unmarkedStates.Push(DFAStartState);
while (unmarkedStates.Count > 0)
{
var processingDFAState = unmarkedStates.Pop();
State dest = null;
foreach (var item in _inputSet)
{
var moveStates = Move(item, processingDFAState.NFAStatesSet);
var epsilonClosureStats = EpsilonClosure(moveStates);
bool found = false;
foreach (var s in _DFA.GetStates())
{
if (SameStatesSet(s.NFAStatesSet, epsilonClosureStats))
{
found = true;
dest = s;
break;
}
}
if (!found)
{
var newState = new State(++_nextStateId, epsilonClosureStats);
unmarkedStates.Push(newState);
_DFA.PushBack(newState);
processingDFAState.AddTransition(item, newState);
}
else
{
processingDFAState.AddTransition(item, dest);
}
}
}
}
