Custom Enumerators

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;

namespace CircularEnumDemo
{
    class Program
    {
        const int max = 15;  // Max number of iterations to stop circular enumerator

        static void Main(string[] args)
        {
            SortedList<int, string> list = new SortedList<int,string>();

            list.Add(1, "one");
            list.Add(2, "two");
            list.Add(3, "three");
            list.Add(4, "four");
            list.Add(5, "five");
            list.Add(6, "six");
            list.Add(7, "seven");
            list.Add(8, "eight");
            list.Add(9, "nine");
            list.Add(10, "ten");

            Console.WriteLine("Dictionary circular enumeration:");
            int i = 0;
            foreach (KeyValuePair<int, string> pair in Enumerators.CircularEnum(list))
            {
                Console.WriteLine("   " + pair.ToString());
                if (++i >= max)
                    break;   // stop circular enumerator, will be infinite if not
            }
            Console.WriteLine("   (stopped)\r\n");

            Console.WriteLine("Dictionary values circular enumeration:");
            i = 0;
            foreach (string value in Enumerators.CircularEnum(list.Values))
            {
                Console.WriteLine("   " + value.ToString());
                if (++i >= max)
                    break;   // stop circular enumerator, will be infinite if not
            }
            Console.WriteLine("   (stopped)\r\n");

            Console.WriteLine("Reverse enumeration:");
            foreach (string value in Enumerators.ReverseEnum(list.Values))
            {
                Console.WriteLine("   " + value.ToString());
            }
            Console.WriteLine("   (finished)\r\n");

            Console.WriteLine("Constrained enumeration (2,5):");
            foreach (KeyValuePair<int, string> pair in Enumerators.ConstrainedEnum(list, 2, 5))
            {
                Console.WriteLine("   " + pair.ToString());
            }
            Console.WriteLine("   (finished)\r\n");

            Console.WriteLine("Stepped enumeration (3):");
            foreach (int value in Enumerators.SteppedEnum(list.Keys, 3))
            {
                Console.WriteLine("   " + value.ToString());
            }
            Console.WriteLine("   (finished)\r\n");

            Console.WriteLine("Combined Constrained(2,6)-Stepped(3)-Reverse-Circular enumeration:");
            i = 0;
            foreach (int value in Enumerators.ConstrainedEnum(Enumerators.SteppedEnum(Enumerators.CircularEnum(Enumerators.ReverseEnum(list.Keys)), 3), 2, 6))
            {
                Console.WriteLine("   " + value.ToString());
                if (++i >= max * 2)
                    break;   // stop circular enumerator, will be infinite if not
            }
            Console.WriteLine("   (finished)");

            Console.ReadKey();
        }
    }
}