Map reduce index

gistfile1.cs

public class User
{
	public string Id { get; set; }
	public string[] AssignedFields { get; set; }
}

public class WorkItem
{
	public string DocumentId { get; set; }
	public string FieldId { get; set; }
	public bool Validated { get; set; }
}

public class UserWorkItemIndex : AbstractIndexCreationTask<WorkItem, UserWorkItemIndex.Result>
{
	public class Result
	{
		public string DocumentId { get; set; }
		public string[] ValidatedFields { get; set; }
		public string[] ReadyFields { get; set; }
	}

	public UserWorkItemIndex()
	{
		Map = items => items.Select(i => new
		{
			DocumentId = i.DocumentId,
			ValidatedFields = i.Validated ? new string[] { i.FieldId } : new string[0],
			ReadyFields = !i.Validated ? new string[] { i.FieldId } : new string[0]
		});

		Reduce = result => result
			.GroupBy(i => i.DocumentId)
			.Select(g => new
			{
				DocumentId = g.Key,
				ValidatedFields = g.SelectMany(i => i.ValidatedFields),
				ReadyFields = g.SelectMany(i => i.ReadyFields)
			});
	}
}

//And the query:

using (var session = store.OpenSession())
{
	User user = session.Load<User>("users/1");
	var result = session.Query<WorkItem, UserWorkItemIndex>()
		.Customize(q => q.WaitForNonStaleResults())
		.As<UserWorkItemIndex.Result>()
		.Where(d => d.ValidatedFields.Any(f => f.In(user.AssignedFields)))
		.ToArray();
	Console.WriteLine(JsonConvert.SerializeObject(result, Formatting.Indented));
	session.SaveChanges();
}