public Nfa OneOrMore(Nfa nfa)
{
NfaState head = CreateState();
NfaState tail = CreateState();
Transition.Create(nfa.Tail, nfa.Head);
Transition.Create(head, nfa.Head);
Transition.Create(nfa.Tail, tail);
return(Create(head, tail));
}
public Nfa OneOrNothing(Nfa nfa)
{
if (nfa == null)
{
throw new ArgumentNullException("Operator [?] can't be applied without prefix", "nfa");
}
NfaState head = CreateState();
NfaState tail = CreateState();
Transition.Create(head, nfa.Head);
Transition.Create(nfa.Tail, tail);
Transition.Create(head, tail);
return(Create(head, tail));
}
public Nfa Union(Nfa fst, Nfa snd)
{
if (fst == null)
{
return(snd);
}
if (snd == null)
{
return(fst);
}
NfaState head = CreateState();
NfaState tail = CreateState();
Transition.Create(head, fst.Head);
Transition.Create(head, snd.Head);
Transition.Create(fst.Tail, tail);
Transition.Create(snd.Tail, tail);
return(Create(head, tail));
}
private void SetAcceptance(DfaState dfaState, NfaState nfaState)
{
dfaState.IsAccepting = true;
dfaState.Alias = nfaState.Alias;
}
private HashSet <NfaState> GetEpsilonClosure(NfaState state)
{
return(Nfa.GetStates(state, trans => trans.IsEpsilon));
}
public Nfa Create(NfaState head, NfaState tail)
{
return(new Nfa(head, tail, this));
}
