public interface IRecursible<T>: IEnumerable<IRecursible<T>>;

public static void ForEach<T>(T root, Action<T> action)
  where T: IRecursible<T>
{
  action(root);
  foreach(T child in root)
      ForEach(child, action);
}

class MyItem: IRecursible<MyItem>
{
  // тривиальная реализация интерфейса поскипана
    public string Name;
}

public static PrintAll(MyItem root)
{
  ForEach(root, delegate(MyItem t) { Console.WriteLine(t.Name);});
}

public static MyItem FindFirstStartingWith(MyTtem root, string start)
{
  ForEach(root, 
        delegate(MyItem t) 
        { 
            if (t.Name.StartsWith(start))
                super return t;
        } 
    );
}

public static bool FindFirst(T root, Predicate<T> condition, out T result)
  where T: IRecursible<T>
{
  
  if(condition(root))
    {
      result = root;
        return true;
    }
    foreach(T child in root)
    {
      if (FindFirst(child, condition, out result))
            return true;
    }
    return false;
}

public static MyItem FindFirstStartingWith(MyItem root, string start)
{
  MyItem result;
  if (FindFirst(root, delegate(MyItem t) { return t.Name.StartsWith(start);}, out result))
      return result
    else
        return null;
}

public static IEnumerable<T> IterateThrough<T>(T root)
    where T: IRecursible<T>
{
  yield return root;
    foreach(T child in root)
      foreach(T grandchild in IterateThrough(child))
          yield return grandchild;
}

public static void PrintAll(MyItem root)
{
  foreach(MyItem item in IterateThrough(root))
      Console.WriteLine(item.Name);
}
public static MyItem FindFirstStartingWith(MyItem root, string start)
{
  foreach(MyItem item in IterateThrough(root))
      if (item.Name.StartsWith(start)
            return item;
    return null;
}

1.1.4 stable rev. 510

S>System.Web.UI.BaseParser.aspCodeRegex
...
S>System.Web.Util.Wildcard.backslashRegex;
S>...
S>

internal class Wildcard
...
public class BaseParser
{
    ...
    internal static readonly Regex aspCodeRegex;
    internal static readonly Regex aspExprRegex;
    internal static readonly Regex commentRegex;
    internal static readonly Regex databindExprRegex;
    internal static readonly Regex directiveRegex;
    internal static readonly Regex endtagRegex;
    internal static readonly Regex gtRegex;
    internal static readonly Regex includeRegex;
    internal static readonly Regex ltRegex;
    internal static readonly Regex runatServerRegex;
    internal static readonly Regex serverTagsRegex;
    internal static readonly Regex tagRegex;
    internal static readonly Regex textRegex;
}