public static SyntaxTreeNode Convert(string regex)
{
RegexToSyntaxTreeConverter converter = new RegexToSyntaxTreeConverter();
SyntaxTreeNode result = converter.DoConvert(regex).SetPositions();
result.TopParent().CalculateFollowPos();
return(result);
}
private Node DoConvert(string regex)
{
SyntaxTreeNode result = RegexToSyntaxTreeConverter.Convert(regex);
SyntaxTreeNode s = result;
SyntaxTreeNode topParent = s;
while (s != null)
{
if (s.Parent != null)
{
topParent = s.Parent;
}
s = s.Parent;
}
TopSyntaxTreeNode = topParent;
Alphabet = topParent.LeafNodes().Distinct().ToList();
Dictionary <Node, SyntaxTreeNodeSet> DStates = new Dictionary <Node, SyntaxTreeNodeSet>();
Node startNode = new Node();
startNode.IsEntry = true;
DStates.Add(startNode, new SyntaxTreeNodeSet(topParent.FirstPos()));
List <Node> MarkedStates = new List <Node>();
List <(Node, char, Node)> DTrans = new List <(Node, char, Node)>();
while (DStates.Keys.Any(x => !MarkedStates.Contains(x)))
{
Node S = DStates.Keys.First(x => !MarkedStates.Contains(x));
MarkedStates.Add(S);
foreach (char a in Alphabet)
{
SyntaxTreeNodeSet U = new SyntaxTreeNodeSet(DStates[S].Where(x => x.Character == a).SelectMany(x => x.FollowPos).Distinct().ToList());
bool isAccepting = U.Any(x => x.Character == '#');
if (U.Any())
{
Node targetNode = DStates.FirstOrDefault(x => x.Value.IsEqualTo(U)).Key;
if (targetNode == null)
{
targetNode = new Node();
if (isAccepting)
{
targetNode.IsAccepting = true;
}
DStates.Add(targetNode, U);
}
else
{
targetNode.IsAccepting = true;
}
if (a != '#')
{
DTrans.Add((S, a, targetNode));
new Edge(a, S, targetNode);
}
}
}
}
return(startNode);
}
