private void FindDFAParameters(IEnumerable <string> alphabet,
IEnumerable <NodeNFA> startingNodes,
ref Dictionary <NodeDFA, Dictionary <string, IEnumerable <NodeNFA> > > rawDFAParameters)
{
var newNodeDFAName = string.Concat(startingNodes.Select(x => x.Name));
if (rawDFAParameters.Keys.Select(x => x.Name).Contains(newNodeDFAName))
{
return;
}
var isAccepting = startingNodes.Any(x => x.IsAccepting);
var newNodeDFA = new NodeDFA(newNodeDFAName, isAccepting);
rawDFAParameters.Add(newNodeDFA, new Dictionary <string, IEnumerable <NodeNFA> >());
foreach (var symbol in alphabet)
{
var symbolNodes = new HashSet <NodeNFA>();
foreach (var node in startingNodes)
{
symbolNodes.UnionWith(node.Associations[symbol]);
}
rawDFAParameters[newNodeDFA].Add(symbol, symbolNodes);
FindDFAParameters(alphabet, symbolNodes, ref rawDFAParameters);
}
}
public void AutomateMatchWorks(string candidate, bool expected)
{
//Automate pour le regex (ab)*
NodeDFA s0 = new NodeDFA(true);
NodeDFA s1 = new NodeDFA(false);
NodeDFA s2 = new NodeDFA(false);
NodeDFA s3 = new NodeDFA(false);
s0.Add('a', s1);
s0.Add('b', s3);
s1.Add('a', s3);
s1.Add('b', s2);
s2.Add('a', s1);
s2.Add('b', s3);
s3.Add('a', s3);
s3.Add('b', s3);
Automate dfa = new Automate(s0);
Assert.That(dfa.Match(candidate), Is.EqualTo(expected));
}
public DFA ToDFA()
{
var nodes = GetAllNodes().Select(n => n as NodeNFA);
foreach (var node in nodes)
{
if (node.EpsilonPath != null && node.EpsilonPath.Any())
{
nodes = RemoveEpsilonPasses().GetAllNodes().Select(n => n as NodeNFA);
break;
}
}
// At this point I for sure have NFA
var nodesDFA = new List <NodeDFA>();
var startingNode = nodes.Where(n => n.Name == StartingNode.Name).Single();
var rawDFAParameters = new Dictionary <NodeDFA, Dictionary <string, IEnumerable <NodeNFA> > >();
FindDFAParameters(Alphabet, new[] { startingNode }, ref rawDFAParameters);
nodesDFA.AddRange(rawDFAParameters.Keys);
// If any qx(symbol) leads to null, create nullnode
foreach (var nodeDFA in rawDFAParameters)
{
var a = nodeDFA.Value.Values.ToList();
if (nodeDFA.Value.Values.Any(x => x == null || !x.Any()))
{
var nullNode = new NodeDFA("null", false);
foreach (var symbol in Alphabet)
{
nullNode.ConnectWith(nullNode, symbol);
}
nodesDFA.Add(nullNode);
break;
}
}
/*
* What I have here:
* - DFA nodes with no connections created
* - rawDFAParameters
*/
foreach (var nodeDFA in nodesDFA.Where(x => x.Name != "null"))
{
foreach (var symbol in Alphabet)
{
var rawConnection = rawDFAParameters[nodeDFA][symbol];
if (rawConnection == null || !rawConnection.Any())
{
nodeDFA.ConnectWith(nodesDFA.Where(x => x.Name == "null").Single(), symbol);
}
else
{
var nodeToConnect = nodesDFA.Where(x => x.Name == string.Concat(rawConnection.Select(x => x.Name))).Single();
nodeDFA.ConnectWith(nodeToConnect, symbol);
}
}
}
var startingNodeDFA = nodesDFA.Where(x => x.Name == startingNode.Name).Single();
var newDFA = new DFA(Alphabet, startingNodeDFA);
return(newDFA);
}
