Partition Operator

partition.cs

public static IEnumerable<IList<T>> Partition<T>(this IEnumerable<T> collection, int windowSize)
{
    if (collection == null)
        throw new ArgumentNullException("collection");

    List<T> list;
    using (var enumerator = collection.GetEnumerator())
    {
        // Break on an empty sequence to avoid a pointless allocation.
        if (!enumerator.MoveNext())
            yield break;

        list = new List<T>(windowSize);

        do
        {
            list.Add(enumerator.Current);

            if (list.Count == windowSize)
            {
                yield return list;
                list = new List<T>(windowSize);
            }
        }
        while (enumerator.MoveNext());
    }

    if (list.Count != 0)
    {
        yield return list;
    }
}