public REG_EXP(string regExp_str)
{
this.regExp_str = regExp_str;
nfaGraph = new NFA_GRAPH(regExp_str);
eClosureGraph = new E_CLOSURE_GRAPH(nfaGraph);
dfaGraph = new DFA_GRAPH(eClosureGraph);
}
public DFA_GRAPH(E_CLOSURE_GRAPH eClosureGraph)
{
if (eClosureGraph != null)
{
DFASets = new List <NODES_SET>();
DFANodes = new List <NODE>();
Get_DFAGraphFromEClosureGraph(eClosureGraph);
Perform_DFAMinimization();
}
NODE.ClearCount();
NODES_SET.ClearCount();
}
private void Get_DFAGraphFromEClosureGraph(E_CLOSURE_GRAPH eClosureGraph)
{
HashSet <E_CLOSURE_NODE> visitedNodes = new HashSet <E_CLOSURE_NODE>();
Stack <E_CLOSURE_NODE> EClosureNodesToProcess = new Stack <E_CLOSURE_NODE>();
Stack <NODE> NodesToProcess = new Stack <NODE>();
E_CLOSURE_NODE eClosureNodeInProcess = null;
NODE node = null;
NODE newNode = null;
EClosureNodesToProcess.Push(eClosureGraph.StartNode);
startNode = NODE.CreateNode(eClosureGraph.StartNode.nodeType, eClosureGraph.StartNode.NodeID);
NodesToProcess.Push(startNode);
while (EClosureNodesToProcess.Count != 0)
{
eClosureNodeInProcess = EClosureNodesToProcess.Pop();
node = NodesToProcess.Pop();
visitedNodes.Add(eClosureNodeInProcess);
DFANodes.Add(node);
foreach (EDGE edge in eClosureNodeInProcess.edges)
{
if (!visitedNodes.Contains((E_CLOSURE_NODE)edge.nextNode))
{
newNode = NODE.CreateNode(edge.nextNode.nodeType, edge.nextNode.NodeID);
}
else
{
newNode = DFANodes.Find(findNode => findNode.NodeID == edge.nextNode.NodeID);
}
node.edges.Add(new EDGE(edge.transitionCharacter, newNode));
if (!visitedNodes.Contains((E_CLOSURE_NODE)edge.nextNode))
{
EClosureNodesToProcess.Push((E_CLOSURE_NODE)edge.nextNode);
NodesToProcess.Push(newNode);
}
}
}
}
