public void DFA_RemoveTrapStates()
{
var dfa = new DFATable();
var a = dfa.CreateNode();
var c = dfa.CreateNode();
a.IsFinal = true;
dfa.StartState = a;
dfa.AddTransition(a, a, "0");
dfa.AddTransition(a, c, "1");
dfa.AddTransition(c, c, "1");
dfa.AddTransition(c, c, "0");
var nfa = dfa.RemoveTrapStates();
Assert.AreEqual(1, nfa.Nodes.Count());
Assert.AreEqual(1, nfa.Transitions.Count());
Assert.AreEqual(0, nfa.Transitions.First().Source.ID);
Assert.AreEqual(0, nfa.Transitions.First().Destination.ID);
Assert.AreEqual("0", nfa.Transitions.First().Symbol);
Assert.AreEqual(1, nfa.GetAllPossibleSymbols().Count);
Assert.IsTrue(nfa.GetAllPossibleSymbols().Contains("0"));
}
public DFATests()
{
dfa = new DFATable();
a = dfa.CreateNode();
b = dfa.CreateNode();
c = dfa.CreateNode();
d = dfa.CreateNode();
e = dfa.CreateNode();
f = dfa.CreateNode();
dfa.StartState = a;
c.IsFinal = true;
d.IsFinal = true;
e.IsFinal = true;
dfa.AddTransition(a, b, "0");
dfa.AddTransition(a, c, "1");
dfa.AddTransition(b, a, "0");
dfa.AddTransition(b, d, "1");
dfa.AddTransition(c, f, "1");
dfa.AddTransition(c, e, "0");
dfa.AddTransition(d, e, "0");
dfa.AddTransition(d, f, "1");
dfa.AddTransition(e, e, "0");
dfa.AddTransition(e, f, "1");
dfa.AddTransition(f, f, "1");
dfa.AddTransition(f, f, "0");
}
internal DFATable ToDFATable()
{
var dfa = new DFATable();
var nodes = dfa.CreateNodes(this._rows.Count);
foreach (var row in this._rows)
{
var node = nodes[this._rowMapping[row.GetStatesIdentifier()]];
node.IsFinal = row.IsRowFinal();
foreach (var n in row.States)
{
node.UnionTags(n.GetTags());
}
foreach (var symbol in this._symbols)
{
if (symbol == NFATable.Epsilon)
{
continue;
}
var source = node;
var destination = nodes[this._rowMapping[row.GetTransition(symbol).GetIdentifier()]];
dfa.AddTransition(source, destination, symbol);
}
}
// First row should be the start state.
dfa.StartState = nodes[this._rowMapping[this._rows[0].GetStatesIdentifier()]];
return(dfa);
}
public void MakeOneFinalState()
{
// It converts dfa to nfa
if (this.Finish.Count > 1)
{
this.Alphabet = this.Alphabet.Concat(new char[] { 'ε' }.ToList()).ToList();
// Adding eps trans to nothing for every state
for (int i = 0; i < this.DFATable.Count; i++)
{
this.DFATable[i].Add(new List <int>());
}
// Adding new state to direct prev final states to this one
var newFinalState = new List <List <int> >();
// Adding empty trans
for (int i = 0; i < Alphabet.Count; i++)
{
newFinalState.Add(new List <int>());
}
DFATable.Add(newFinalState);
// Point prev final states to new state
for (int i = 0; i < this.Finish.Count; i++)
{
DFATable[this.Finish[i]][this.Alphabet.IndexOf(Translation.Eps)].Add(this.DFATable.IndexOf(newFinalState));
}
this.Finish = new List <int>()
{
this.DFATable.IndexOf(newFinalState)
};
}
}
