private Alternative ParseAlternative()
{
var alt = new Alternative();
var first = new HashSet<TokenType>()
{
TokenType.CHAR,
TokenType.OPENCLASS,
TokenType.OPENGROUP,
};
while (first.Contains(_ts.Peek().Type))
{
alt.Factors.Add(ParseMatchOp());
}
return alt;
}
public NFAGraph(Alternative alt)
{
InstantiateFromAlternative(alt);
}
private void InstantiateFromAlternative(Alternative alt)
{
_startState = NewState();
_finishState.Add(NewState());
var curtail = _startState;
foreach (var mf in alt.Factors)
{
var mfnfa = new NFAGraph(mf);
CopyInto(mfnfa);
var nl = new NFALink();
nl.IsEmpty = true;
nl.Target = mfnfa._startState;
_adjList[curtail].Add(nl);
curtail = mfnfa._finishState.Single();
}
var nel = new NFALink();
nel.IsEmpty = true;
nel.Target = _finishState.Single();
_adjList[curtail].Add(nel);
}
