private NFAState NewState()
{
var state = new NFAState();
_nodes.Add(state);
_adjList.Add(state, new List<NFALink>());
return state;
}
private bool SimulateMatch(string input, int ptr, NFAState curNode)
{
var c = ptr < input.Length ? input[ptr] : (char?)null;
foreach (var link in _adjList[curNode])
{
bool res = false;
if (c.HasValue && CanFollowLink(link, c.Value))
res = SimulateMatch(input, ptr + 1, link.Target);
else if (link.IsEmpty)
res = SimulateMatch(input, ptr, link.Target);
if (res == true) return true;
}
return _finishState.Contains(curNode);
}
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 InstantiateFromCharClass(CharacterClass CClass)
{
_startState = NewState();
_finishState.Add(NewState());
var link = new NFALink();
link.CharClass = CClass;
link.Target = _finishState.Single();
_adjList[_startState].Add(link);
}
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 HashSet<NFAState> eClosure(NFAState target)
{
var rset = new HashSet<NFAState>();
rset.Add(target);
foreach (var link in _adjList[target])
{
if (link.IsEmpty)
rset.UnionWith(eClosure(link.Target));
}
return rset;
}
private void CopyIntoWithTerminals(NFAGraph other)
{
CopyInto(other);
this._startState = other._startState;
this._finishState = other._finishState;
}
