private void InstantiateFromRegex(RegExpr re)
{
_startState = NewState();
_finishState.Add(NewState());
foreach (var alt in re.Alternatives)
{
var altnfa = new NFAGraph(alt);
CopyInto(altnfa);
var nsl = new NFALink();
var nfl = new NFALink();
nsl.IsEmpty = true;
nfl.IsEmpty = true;
nsl.Target = altnfa._startState;
nfl.Target = _finishState.Single();
_adjList[_startState].Add(nsl);
_adjList[altnfa._finishState.Single()].Add(nfl);
}
}
private void InstantiateFromMatchFactorOp(MatchFactorWithOp mop)
{
var mf = new NFAGraph(mop.Factor);
CopyIntoWithTerminals(mf);
switch (mop.Op.Type)
{
case UnaryOperatorType.None:
break;
case UnaryOperatorType.Optional:
var elink1 = new NFALink();
elink1.IsEmpty = true;
elink1.Target = _finishState.Single();
_adjList[_startState].Add(elink1);
break;
case UnaryOperatorType.OneMany:
var elink2 = new NFALink();
elink2.IsEmpty = true;
elink2.Target = _startState;
_adjList[_finishState.Single()].Add(elink2);
break;
case UnaryOperatorType.NoneMany:
var newend = NewState();
var blink = new NFALink();
var flink = new NFALink();
blink.IsEmpty = true;
flink.IsEmpty = true;
blink.Target = _startState;
flink.Target = newend;
_adjList[_finishState.Single()].Add(blink);
_adjList[_startState].Add(flink);
_finishState = new HashSet<NFAState>{newend};
break;
}
}
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);
}
private void InstantiateFromCharClass(CharacterClass CClass)
{
_startState = NewState();
_finishState.Add(NewState());
var link = new NFALink();
link.CharClass = CClass;
link.Target = _finishState.Single();
_adjList[_startState].Add(link);
}
private bool CanFollowLink(NFALink link, char c)
{
if (link.CharClass == null) return false;
return link.CharClass.Elements.Any(el => el.StartC >= c && el.EndC <= c);
}