WTState processNode(WTReNode node, WTState state, int length)
{
if (node is WTReEndOfString)
{
WTState finalState = new WTState();;
finalState.isFinal = true;
WTTransition tran = new WTTransition();
tran.node = (WTReCharacterBase)node;
tran.nextState = finalState;
state.transitions.Add(tran);
return(finalState);
}
else if (node is WTReCharacterBase)
{
WTState finalState = new WTState();
WTTransition tran = new WTTransition();;
tran.node = (WTReCharacterBase)node;
tran.nextState = finalState;
state.transitions.Add(tran);
return(finalState);
}
else if (node is WTReQuantifier)
{
WTReQuantifier qtf = (WTReQuantifier)node;
WTState curState = state;
for (int i = 0; i < qtf.countFrom; i++)
{
curState = processNode(qtf.child, curState, length);
}
if (qtf.countTo == qtf.countFrom)
{
// strict quantifier
return(curState);
}
WTState finalState = new WTState();;
for (int i = qtf.countFrom; i < Math.Min(qtf.countTo, length); i++)
{
WTState nextState = processNode(qtf.child, curState, length);
WTTransition _tran = new WTTransition();
_tran.node = null;
_tran.nextState = finalState;
if (qtf.greedy)
{
curState.transitions.Add(_tran);
}
else
{
curState.transitions.Insert(0, _tran);
}
curState = nextState;
}
WTTransition tran = new WTTransition();
tran.node = null;
tran.nextState = finalState;
curState.transitions.Add(tran);
return(finalState);
}
else if (node is WTReGroup)
{
WTReGroup grp = (WTReGroup)node;
WTState curState = state;
for (int i = 0; i < grp.children.Count; i++)
{
curState = processNode(grp.children[i], curState, length);
}
if (!grp.capturing && grp.children.Count == 1 && (grp.children[0] is WTReLiteral))
{
WTTransition tran = new WTTransition();
tran.node = null;
tran.bypassNode = (WTReLiteral)grp.children[0];
tran.nextState = curState;
state.transitions.Add(tran);
}
return(curState);
}
else if (node is WTReAlteration)
{
WTReAlteration alt = (WTReAlteration)node;
WTState finalState = new WTState();
for (int i = 0; i < alt.children.Count; i++)
{
WTState curState = processNode(alt.children[i], state, length);
WTTransition tran = new WTTransition();
tran.node = null;
tran.nextState = finalState;
curState.transitions.Add(tran);
}
return(finalState);
}
else
{
return(null);
}
}
WTState stateDSF(WTState initial, WTState fin, StringBuilder input, int startPos)
{
List <PathEntry> path = new List <PathEntry>();
path.Add(new PathEntry(initial, startPos));
while (path.Count > 0)
{
int depth = path.Count - 1;
WTState parent = path[depth].getState();
int vertexNum = path[depth].getVertex();
int position = path[depth].getPosition();
if (parent != null && parent.isFinal)
{
try {
for (int i = path.Count - 1; i > 0; i--)
{
WTTransition tran = path[i - 1].getState().transitions[path[i - 1].getVertex() - 1];
if (tran.bypassNode != null)
{
input.Insert(path[i].getPosition(), tran.bypassNode.character.ToString());
}
}
} catch (Exception e) {
//e.printStackTrace();
}
return(parent);
}
if (position > input.Length)
{
path[depth].setVertex(vertexNum + 1);
path.Add(new PathEntry(fin));
continue;
}
if (parent != null && parent.transitions.Count > vertexNum)
{
WTTransition nextTransition = parent.transitions[vertexNum];
if (nextTransition.node != null)
{
char c = (position < input.Length) ? input[position] : (char)0;
if (!nextTransition.node.matchesCharacter(c))
{
if (c == 0)
{
path[depth].setVertex(vertexNum + 1);
path.Add(new PathEntry(fin));
continue;
}
else
{
path[depth].setVertex(vertexNum + 1);
continue;
}
}
else
{
}
position++;
}
path[depth].setVertex(vertexNum + 1);
path.Add(new PathEntry(nextTransition.nextState, position));
}
else
{
path.RemoveAt(depth);
}
}
return(null);
}
