public void CountsOnlyOneFinal()
{
var m1Start = new GraphState () {
IsFinal = true
};
var secondFinal = new GraphState () {
IsFinal = true
};
var thirdFinal = new GraphState () {
IsFinal = true
};
var m1 = new Graph () {
StartState = m1Start
};
var epsilonConnection1 = new GraphStateConnection {
Start = m1Start,
End = secondFinal,
ConnectedBy = Word.Epsilon
};
var epsilonConnection2 = new GraphStateConnection {
Start = secondFinal,
End = thirdFinal,
ConnectedBy = Word.Epsilon
};
m1.StartState.Out.Add (epsilonConnection1);
secondFinal.Out.Add (epsilonConnection2);
var finals = m1.FindFinalStates (m1.StartState);
finals.Count.Should ().Be (3);
}
/// <summary>
/// Performs the Union on two NDFA's.
/// </summary>
/// <param name="m2">The NDFA to Union with.</param>
/// <returns>>A new NDFA that is the union of the two graphs.</returns>
public Graph Union(Graph m2)
{
var m = new Graph ();
var m1 = this;
//new start state
m.StartState = new GraphState ();
//new q0
var newFinalState = new GraphState () {
IsFinal = true
};
//connection from q0 to q1 over epsilon
var q0Toq1 = new GraphStateConnection () {
ConnectedBy = Word.Epsilon,
Start = m.StartState,
End = m1.StartState
};
//connection from q0 to q2
var q0Toq2 = new GraphStateConnection () {
ConnectedBy = Word.Epsilon,
Start = m.StartState,
End = m2.StartState
};
//attach states.
m.StartState.Out.Add (q0Toq1);
m.StartState.Out.Add (q0Toq2);
var m1Finals = FindFinalStates (m1.StartState);
var m2Finals = FindFinalStates (m2.StartState);
foreach (var final in m1Finals) {
final.IsFinal = false;
var finalConnection = new GraphStateConnection () {
Start = final,
End = newFinalState,
ConnectedBy = Word.Epsilon
};
final.Out.Add (finalConnection);
}
foreach (var final in m2Finals) {
final.IsFinal = false;
var finalConnection = new GraphStateConnection () {
Start = final,
End = newFinalState,
ConnectedBy = Word.Epsilon
};
final.Out.Add (finalConnection);
}
//update the total state count
m.StateCount = m1.StateCount + m2.StateCount + 2;
if (updateStateNumber) {
RenumberStates (m.StartState);
}
return m;
}
/// <summary>
/// Concatinates two NDFA's.
/// </summary>
/// <param name="m1">The second NDFA to concatinate with.</param>
/// <returns>The new graph that is this and m1 concatinated.</returns>
public Graph Concat(Graph m1)
{
var m = new Graph ();
var m2 = this;
var m1FinalStates = m1.FindFinalStates (m1.StartState);
foreach (var finalState in m1FinalStates) {
//create a new connection to m2 initial state
var m1FinalTom2Initial = new GraphStateConnection () {
Start = finalState,
End = m2.StartState,
ConnectedBy =
Word.Epsilon
};
//make the connection
finalState.Out.Add (m1FinalTom2Initial);
//kill m1 final states and leave m2 as finals for m
finalState.IsFinal = false;
}
//update state count for new graph
m.StartState = m1.StartState;
m.StateCount = m1.StateCount + m2.StateCount;
if (updateStateNumber) {
RenumberStates (m.StartState);
}
return m;
}
/// <summary>
/// Perfoms a Kleene operation on the graph.
/// </summary>
/// <returns>The new graph after the Kleene operation.</returns>
public Graph Kleene()
{
var m = new Graph ();
var m1 = this;
var finals = FindFinalStates (m1.StartState);
var oldInitial = m1.StartState;
//create new init and final state.
var newInitial = new GraphState (){
IsFinal = true,
StateNumber = m1.StateCount + 1
};
//create connection from new initial to the old initial through epsilon
var initialEpsilonConnection = new GraphStateConnection {
End = oldInitial,
Start = newInitial,
ConnectedBy = Word.Epsilon
};
//add the connection to the states.
newInitial.Out.Add (initialEpsilonConnection);
foreach (var finalState in finals) {
//now create epsilon connections from final to original start state
var finalToOldInitialConnection = new GraphStateConnection {
End = newInitial,
Start = finalState,
ConnectedBy = Word.Epsilon
};
finalState.IsFinal = false;
//now connect them
finalState.Out.Add(finalToOldInitialConnection);
}
//now attach the new init state to the graph
m.StartState = newInitial;
m.StateCount = m1.StateCount + 1;
return m;
}