C# Ranking of objects, multiple criteria

Question

I am building a plugin for a LAN party website that I wrote that would allow the use of a Round Robin tournament.

All is going well, but I have some questions about

Answer 1

Ranking isn't too hard. Just mishmash OrderBy and Select implementation patterns together and you can have an easy to use Ranking extension method. Like this:

    public static IEnumerable Rank
    (
      this IEnumerable source,
      Func keySelector,
      Func selector
    )
    {
        if (!source.Any())
        {
            yield break;
        }

        int itemCount = 0;
        T[] ordered = source.OrderBy(keySelector).ToArray();
        TKey previous = keySelector(ordered[0]);
        int rank = 1;
        foreach (T t in ordered)
        {
            itemCount += 1;
            TKey current = keySelector(t);
            if (!current.Equals(previous))
            {
                rank = itemCount;
            }
            yield return selector(t, rank);
            previous = current;
        }
    }

Here's some test code

string[] myNames = new string[]
{ "Bob", "Mark", "John", "Jim", "Lisa", "Dave" };
//
var query = myNames.Rank(s => s.Length, (s, r) => new { s, r });
//
foreach (var x in query)
{
  Console.WriteLine("{0} {1}", x.r, x.s);
}

Which yields these results:

1 Bob
1 Jim
3 Mark
3 John
3 Lisa
3 Dave