Enumerable "converter" (w/ lambda)

EnumHelper.cs

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

namespace EnumHelper
{
    public class EnumeratorAdapter<T, K> : IEnumerator<K>
    {
        private IEnumerator<T> Enumerator = null;

        private Func<T, K> Map = null;

        public EnumeratorAdapter(IEnumerator<T> enumerator, Func<T, K> map)
        {
            Enumerator = enumerator;
            Map = map;
        }

        void IDisposable.Dispose() { Enumerator.Dispose(); }

        object IEnumerator.Current { get { return Current; } }

        public bool MoveNext() { return Enumerator.MoveNext(); }
        public void Reset() { Enumerator.Reset(); }
        public K Current { get { return Map(Enumerator.Current); } }
    }

    public class EnumerableAdapter<T> : IEnumerable<T>
    {
        private IEnumerator<T> enumeratorAdaper = null;
        public EnumerableAdapter(IEnumerator<T> enumAdaper) { enumeratorAdaper = enumAdaper; }
        public IEnumerator<T> GetEnumerator() { return enumeratorAdaper; }
        IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
    }

    public static class EnumerableAdapterHelper
    {
        public static IEnumerable<K> MapEnum<T, K>(this IEnumerable<T> ienum, Func<T, K> map)
        {
            return new EnumerableAdapter<K>(new EnumeratorAdapter<T, K>(ienum.GetEnumerator(), map));
        }
    }
}

List<string> l = new List<string>();
l.Add("1");
l.Add("2");
l.Add("3");
var intenum = l.MapEnum<string, int>(s => int.Parse(s));
foreach (int p in intenum)
  System.Console.WriteLine(p * 10);

I know you can just use Linq...

List<string> mylist = new List<string>();
mylist.Add("1");
mylist.Add("2");
mylist.Add("3");
var newlist = from li in mylist select int.Parse(li);