LINQ.NextPrev.Extensions.cs

private static T GetNext<T>(IEnumerable<T> list, T current)
{
	try
	{
		if (list.Last().Equals(current))
		{
			return list.First();
		}

		return list.SkipWhile(x => !x.Equals(current)).Skip(1).First();
	}
	catch
	{
		return default(T);
	}
}

private static T GetPrevious<T>(IEnumerable<T> list, T current)
{
	try
	{
		if (list.First().Equals(current))
		{
			return list.Last();
		}

		return list.TakeWhile(x => !x.Equals(current)).Last();
	}
	catch
	{
		return default(T);
	}
}