public Dfa.DfaTable BuildDfa()
{
Nfa.Nfa nfa = nfaWorker.Compile();
// -- from here build DFA out of NFA
List <DfaNode> done = new List <DfaNode>();
List <Link> to_add = (new[] { new Link(null, 0, new DfaNode(nfa.StartNode)) }).ToList();
while (to_add.Any())
{
// build closures for incoming nodes
to_add.Select(it => it.Target).ForEach(it => it.BuildClosure());
List <Link> new_links = new List <Link>();
foreach (Link link in to_add)
{
// check if we already have that DFA node
DfaNode existing = done.SingleOrDefault(it => it.SameNfaCore(link.Target));
if (existing == null)
{
done.Add(link.Target);
if (link.Source != null)
{
link.Source.ConnectTo(link.Edge, link.Target);
}
new_links.AddRange(link.Target.ComputeLinks());
}
else
{
link.Source.ConnectTo(link.Edge, existing);
}
}
to_add = new_links;
}
done.ZipWithIndex().ForEach(it => it.Item1.Index = it.Item2);
var dfa = new Dfa.DfaTable(done.Count);
foreach (DfaNode node in done)
{
dfa.SetAccepting(node.Index, node.AcceptingValues);
node.CreateTransitions(dfa);
}
return(dfa);
}
