private static void RecalculationList(string name, Surf.Set dependents, Surf.Set recalculationList)
{
if (recalculationList.Contains(name))
{
throw new System.Exception("Cycle detected.");
}
recalculationList.Add(name);
if (dependents.IsDefined(name))
{
foreach (string dependent in (Surf.Set)dependents.Apply(name))
{
RecalculationList(dependent, dependents, recalculationList);
}
}
}
private static Surf.Set EpsilonClosure(Surf.Set states, Surf.Set transitions, Surf.Set epsilonCache)
{
Surf.Tuple key = Tuple(states);
if (epsilonCache.IsDefined(key))
{
return((Surf.Set)epsilonCache.Apply(key));
}
//System.Console.WriteLine("START EpsilonClosure " + System.DateTime.Now.ToString());
Surf.Set epsilonClosure = new Surf.Set();
Stack <int> worklist = new Stack <int>();
foreach (int state in states)
{
epsilonClosure.Add(state);
worklist.Push(state);
}
while (worklist.Count > 0)
{
int state = worklist.Pop();
foreach (Surf.Tuple transition in transitions)
{
Surf.Tuple input = (Surf.Tuple)transition[0];
if (input.Count == 1 && (int)input[0] == state)
{
int toState = (int)transition[1];
if (!epsilonClosure.Contains(toState))
{
epsilonClosure.Add(toState);
worklist.Push(toState);
}
}
}
}
epsilonCache.Add(new Surf.Tuple(new object[] { key, epsilonClosure }));
//System.Console.WriteLine("END EpsilonClosure " + System.DateTime.Now.ToString());
return(epsilonClosure);
}
public static FiniteAutomaton DFA(Bamboo.Parsing.FiniteAutomata.FiniteAutomaton nfa, Counter counter)
{
System.Console.WriteLine("START DFA " + System.DateTime.Now.ToString());
Surf.Set epsilonCache = new Surf.Set();
Surf.Set moveCache = new Surf.Set();
Surf.Set nfa_transitions = Set(nfa.Transitions);
Dictionary <string, int> nfa_transitions_lookup = new Dictionary <string, int>();
foreach (Surf.Tuple transition in nfa_transitions)
{
Surf.Tuple input = (Surf.Tuple)transition[0];
if (input.Count == 2)
{
int state = (int)input[0];
char ch = (char)input[1];
nfa_transitions_lookup.Add("" + state + "::" + ch, (int)transition[1]);
}
}
Surf.Set q0 = EpsilonClosure(new Surf.Set(new object[] { nfa.StartState }), nfa_transitions, epsilonCache);
Surf.Set Q = new Surf.Set(); // A set whose element are sets of states that are subsets of N.
Q.Add(q0);
Surf.Set T = new Surf.Set();
Stack <Surf.Set> worklist = new Stack <Surf.Set>();
worklist.Push(q0);
while (worklist.Count > 0)
{
Surf.Set q = worklist.Pop();
foreach (char character in nfa.Alphabet)
{
Surf.Set t = EpsilonClosure(Move(q, character, nfa_transitions_lookup), nfa_transitions, epsilonCache);
if (t.Count > 0)
{
T.Add(new Surf.Tuple(new object[] { new Surf.Tuple(new object[] { q, character }), t }));
if (!Q.Contains(t))
{
Q.Add(t);
worklist.Push(t);
}
}
}
}
Surf.Set states = new Surf.Set();
Surf.Set alphabet = new Surf.Set();
Surf.Set transitions = new Surf.Set();
int startState;
Surf.Set finalStates = new Surf.Set();
Surf.Set tokens = new Surf.Set();
Surf.Set D = new Surf.Set();
foreach (Surf.Set q in Q)
{
D.Add(new Surf.Tuple(new object[] { q, counter.Next() }));
}
foreach (Surf.Set q in Q)
{
states.Add(D.Apply(q));
}
alphabet = new Surf.Set(nfa.Alphabet);
foreach (Surf.Tuple t in T)
{
Surf.Tuple input = (Surf.Tuple)t[0];
int fromState = (int)D.Apply(input[0]);
char character = (char)input[1];
int toState = (int)D.Apply(t[1]);
transitions.Add(new Surf.Tuple(new object[] { new Surf.Tuple(new object[] { fromState, character }), toState }));
}
startState = (int)states[0];
foreach (int state in nfa.FinalStates)
{
foreach (Surf.Tuple d in D)
{
Surf.Set q = (Surf.Set)d[0];
if (q.Contains(state))
{
finalStates.Add(d[1]);
foreach (int q_state in q)
{
string token = Lookup(nfa.Tokens, (int)q_state);
if (token.Length > 0)
{
tokens.Add(new Surf.Tuple(new object[] { d[1], token }));
break;
}
}
}
}
}
System.Console.WriteLine("END DFA " + System.DateTime.Now.ToString());
//foreach (Token token in nfa.Tokens)
//{
// System.Console.WriteLine(token.Name + " " + token.Number);
//}
//System.Console.WriteLine();
//Surf.Printer.Print(tokens, System.Console.Out);
//System.Console.WriteLine();
//System.Console.WriteLine();
return(Minimize(Reorder(new FiniteAutomaton(states, alphabet, transitions, startState, finalStates, tokens))));
}
