public override int AddToNfa <TResult>(Nfa <TResult> nfa, int targetState)
{
if (choices.Length == 0)
{
return(targetState);
}
if (choices.Length == 1)
{
return(choices[0].AddToNfa(nfa, targetState));
}
var startState = nfa.AddState();
var newChoices = new IMatchable[choices.Length - 1];
Array.Copy(choices, newChoices, newChoices.Length);
var pattern = new UnionPattern(newChoices);
var endState = nfa.AddState();
nfa.AddEpsilon(endState, targetState, NfaTransitionPriority.Low);
nfa.AddEpsilon(startState, choices[choices.Length - 1].AddToNfa(nfa, endState));
endState = nfa.AddState();
nfa.AddEpsilon(endState, targetState);
nfa.AddEpsilon(startState, pattern.AddToNfa(nfa, endState));
return(startState);
}
protected override Pattern CalcReverse()
{
var ret = this;
var newpat = new UnionPattern(choices);
for (var i = 0; i < choices.Length; ++i)
{
var old = newpat.choices[i];
var rev = old.Reversed;
// ReSharper disable once PossibleUnintendedReferenceComparison
if (old != rev)
{
newpat.choices[i] = rev;
ret = newpat;
}
}
return(ret);
}
