void NumberNodes(Node p, State state)
{
/* Assigns a state n.state to every node n. There will be a transition from
* n.state to n.next.state triggered by n.val. All nodes in an alternative
* chain are represented by the same state.
*/
if (p == null)
{
return;
}
if (p.state != null)
{
return; // already visited;
}
if (state == null)
{
state = NewState();
}
p.state = state;
if (tab.DelGraph(p))
{
state.endOf = curSy;
}
switch (p.typ)
{
case Node.clas:
case Node.chr: {
NumberNodes(p.next, null);
break;
}
case Node.opt: {
NumberNodes(p.next, null); NumberNodes(p.sub, state);
break;
}
case Node.iter: {
NumberNodes(p.next, state); NumberNodes(p.sub, state);
break;
}
case Node.alt: {
NumberNodes(p.sub, state); NumberNodes(p.down, state);
break;
}
}
}
public void ConvertToStates(Node p, Symbol sym)
{
curSy = sym;
if (Tab.DelGraph(p))
{
parser.SemErr("token might be empty");
}
NumberNodes(p, firstState, true);
FindTrans(p, true, new BitArray(tab.nodes.Count));
if (p.typ == Node.iter)
{
Step(firstState, p, new BitArray(tab.nodes.Count));
}
}
// Assigns a state n.state to every node n. There will be a transition from
// n.state to n.next.state triggered by n.val. All nodes in an alternative
// chain are represented by the same state.
// Numbering scheme:
// - any node after a chr, clas, opt, or alt, must get a new number
// - if a nested structure starts with an iteration the iter node must get a new number
// - if an iteration follows an iteration, it must get a new number
void NumberNodes(Node p, State state, bool renumIter)
{
if (p == null)
{
return;
}
if (p.state != null)
{
return; // already visited;
}
if (state == null || (p.typ == Node.iter && renumIter))
{
state = NewState();
}
p.state = state;
if (Tab.DelGraph(p))
{
state.endOf = curSy;
}
switch (p.typ)
{
case Node.clas:
case Node.chr: {
NumberNodes(p.next, null, false);
break;
}
case Node.opt: {
NumberNodes(p.next, null, false);
NumberNodes(p.sub, state, true);
break;
}
case Node.iter: {
NumberNodes(p.next, state, true);
NumberNodes(p.sub, state, true);
break;
}
case Node.alt: {
NumberNodes(p.next, null, false);
NumberNodes(p.sub, state, true);
NumberNodes(p.down, state, renumIter);
break;
}
}
}