public void TestVisitExp()
{
string input = @"10 - 2 + 3*4.5";
CalcTreeGenerator G = new CalcTreeGenerator();
Calc_node node = G.Generate(input);
}
private void ShowWindow(Calc_node node)
{
MathRenderer renderer = new MathRenderer();
Window window = new Window();
window.Closed += (s, e) => window.Dispatcher.InvokeShutdown();
Canvas block = renderer.RenderElement(node);
window.Content = block;
window.Show();
System.Windows.Threading.Dispatcher.Run();
}