public static void Visual(Regex re, string path)
{
path = path.Replace('/', '\\');
var sb = new StringBuilder();
var set = new HashSet<string>();
sb.Append("digraph {\n rankdir = \"LR\";\n shape=\"circle\";\n");
sb.Append($" {re.End} [shape=\"doublecircle\"];\n");
Draw(re.Start, sb, set);
sb.Append("}");
if (!Directory.Exists("Temp")) {
Directory.CreateDirectory("Temp");
}
var dotFilePath = $"Temp\\{Path.GetFileNameWithoutExtension(path)}.dot";
File.WriteAllText(dotFilePath, sb.ToString());
var process = new Process();
var startInfo = new ProcessStartInfo {
WindowStyle = ProcessWindowStyle.Hidden,
FileName = "..\\..\\tools\\Graphviz\\dot.exe",
Arguments = $"-Tpng {dotFilePath} -o {path}"
};
process.StartInfo = startInfo;
process.Start();
process.WaitForExit();
}
private void HandleAlt(Token token)
{
var n2 = _regexStack.Pop();
var n1 = _regexStack.Pop();
var s0 = new RegexState();
s0.Epsilon.Add(n1.Start);
s0.Epsilon.Add(n2.Start);
var s3 = new RegexState();
n1.End.Epsilon.Add(s3);
n2.End.Epsilon.Add(s3);
n1.End.IsFinalStates = false;
n2.End.IsFinalStates = false;
var regex = new Regex(s0, s3);
_regexStack.Push(regex);
}
private void HandleConcat(Token token)
{
var n2 = _regexStack.Pop();
var n1 = _regexStack.Pop();
n1.End.IsFinalStates = false;
n1.End.Epsilon.Add(n2.Start);
var regex = new Regex(n1.Start, n2.End);
_regexStack.Push(regex);
}
private void HandleChar(Token token)
{
var s0 = new RegexState();
var s1 = new RegexState();
s0.Transitions.Add(token.Text.First(), s1);
var regex = new Regex(s0, s1);
_regexStack.Push(regex);
}
private void HandleRepeat(Token token)
{
var s0 = _regexStack.Pop();
var s1 = new RegexState();
var s2 = new RegexState();
s1.Epsilon.Add(s0.Start);
if (token.Text == "*") {
s1.Epsilon.Add(s2);
}
s0.End.Epsilon.Add(s2);
s0.End.Epsilon.Add(s0.Start);
s0.End.IsFinalStates = false;
var regex = new Regex(s1, s2);
_regexStack.Push(regex);
}