private String CollapseChain(State state)
{
if (state.mTransitions.Count == 1)
{
State childState = state.mTransitions.Values.First()[0];
String result = CollapseChain(childState);
if (state.mAcceptingState == false)
{
if (result != null)
{
mDFATable.GetStates().Remove(childState);
state.mChain = state.mTransitions.Keys.First() + result;
state.mChainTokenID = childState.mTokenID;
if (childState.mChainDebugTokenName != null && childState.mChainDebugTokenName != String.Empty)
{
state.mChainDebugTokenName = childState.mChainDebugTokenName;
}
else
{
state.mChainDebugTokenName = childState.mDebugTokenName;
}
//state.mAcceptingState = childState.mAcceptingState;
state.mTransitions.Clear();
return(state.mChain);
}
}
}
else if (state.mTransitions.Count == 0)
{
return(String.Empty);
}
else
{
foreach (List <State> states in state.mTransitions.Values)
{
CollapseChain(states[0]);
}
}
return(null);
}
public void SaveGraph(FSATable table, String name)
{
StringBuilder strGraph = new StringBuilder("digraph{\n");
List <State> faStates = table.GetStates();
for (int i = 0; i < faStates.Count; ++i)
{
State state = faStates[i];
String strStateID = state.mStateID.ToString();
strGraph.Append("\t" + strStateID + "\t[");
if (state.mAcceptingState)
{
strGraph.Append("shape=doubleoctagon, ");
}
String label = null;
if (state.mChain != null)
{
strGraph.Append("color=blue, ");
label = state.mChain;
}
if (state.mTokenID != -1)
{
if (label == null)
{
label = "(" + state.mDebugTokenName + ")";
}
else
{
label += " : (" + state.mDebugTokenName + ")";
}
}
if (label != null)
{
strGraph.Append("label=\"" + label + "\", ");
}
strGraph.Append("];\n");
}
strGraph.Append("\n");
// Record transitions
for (int i = 0; i < faStates.Count; ++i)
{
State state = faStates[i];
List <State> states;
state.GetTransitions(Constants.Epsilon, out states);
for (int j = 0; j < states.Count; ++j)
{
// Record transition
String strStateID1 = state.mStateID.ToString();
String strStateID2 = states[j].mStateID.ToString();
strGraph.Append("\t" + strStateID1 + " -> " + strStateID2);
strGraph.Append("\t[label=\"epsilon\"];\n");
}
foreach (char input in mInputSet)
{
state.GetTransitions(input, out states);
for (int j = 0; j < states.Count; ++j)
{
// Record transition
String strStateID1 = state.mStateID.ToString();
String strStateID2 = states[j].mStateID.ToString();
strGraph.Append("\t" + strStateID1 + " -> " + strStateID2);
strGraph.Append("\t[label=\"" + input.ToString() + "\"];\n");
}
}
}
strGraph.Append("}");
File.WriteAllText(@"C:\Temp\" + name + @".gv", strGraph.ToString());
System.Diagnostics.Process.Start(@"C:\Program Files (x86)\Graphviz2.28\bin\dot.exe", @"-Tpng -o""C:\Temp\" + name + @".png"" ""C:\Temp\" + name + @".gv""").Close();
}
private void ConvertNFAtoDFA()
{
mDFATable = new FSATable();
if (mNFATable.GetStates().Count == 0)
{
return;
}
State.mStateIDCounter = 0;
HashSet <State> dfaStartStates;
EpsilonClosure(out dfaStartStates, mNFATable.GetFirstState());
State dfaStartState = new State(dfaStartStates);
mDFATable.AppendState(dfaStartState);
List <State> unmarkedDFAStates = new List <State>();
unmarkedDFAStates.Add(dfaStartState);
while (unmarkedDFAStates.Count != 0)
{
State processingDFAState = unmarkedDFAStates[unmarkedDFAStates.Count - 1];
unmarkedDFAStates.RemoveAt(unmarkedDFAStates.Count - 1);
foreach (char c in mInputSet)
{
HashSet <State> moveResult, epsilonClosureResult;
Move(c, out moveResult, new HashSet <State>(processingDFAState.mNFAStates));
EpsilonClosure(out epsilonClosureResult, moveResult);
bool found = false;
State s = null;
for (int i = 0; i < mDFATable.GetStates().Count; ++i)
{
s = mDFATable.GetState(i);
if (s.mNFAStates.SetEquals(epsilonClosureResult))
{
found = true;
break;
}
}
if (found == false)
{
State u = new State(epsilonClosureResult);
unmarkedDFAStates.Add(u);
mDFATable.AppendState(u);
processingDFAState.AddTransition(c, u);
}
else
{
processingDFAState.AddTransition(c, s);
}
}
}
}