/// <inheritdoc/>
public string ToDot()
{
var writer = new DotWriter <TState>(this.StateComparer);
writer.WriteStart("NFA");
// Accepting states
writer.WriteAcceptingStates(this.AcceptingStates);
// Non-accepting states
writer.WriteStates(this.States.Except(this.AcceptingStates, this.StateComparer));
// Initial states
writer.WriteInitialStates(this.InitialStates);
// Transitions
var tupleComparer = new TupleEqualityComparer <TState, TState>(this.StateComparer, this.StateComparer);
var transitionsByState = this.Transitions.GroupBy(t => (t.Source, t.Destination), tupleComparer);
var remainingEpsilon = this.epsilonTransitions.EpsilonTransitionMap
.ToDictionary(kv => kv.Key, kv => kv.Value.ToHashSet(this.StateComparer), this.StateComparer);
foreach (var group in transitionsByState)
{
var from = group.Key.Item1;
var to = group.Key.Item2;
var on = string.Join(" U ", group.Select(g => g.Symbol));
if (this.EpsilonTransitions.Contains(new(from, to)))
{
remainingEpsilon[from].Remove(to);
on = $"{on}, ε";
}
writer.WriteTransition(from, on, to);
}
// Epsilon-transitions
foreach (var(from, toSet) in remainingEpsilon)
{
foreach (var to in toSet)
{
writer.WriteTransition(from, "ε", to);
}
}
writer.WriteEnd();
return(writer.Code.ToString());
}