jellyfin-server/RSSDP/IEnumerableExtensions.cs
2020-06-20 20:35:29 +12:00

35 lines
950 B
C#

using System;
using System.Collections.Generic;
using System.Linq;
namespace Rssdp.Infrastructure
{
internal static class IEnumerableExtensions
{
public static IEnumerable<T> SelectManyRecursive<T>(this IEnumerable<T> source, Func<T, IEnumerable<T>> selector)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (selector == null)
{
throw new ArgumentNullException(nameof(selector));
}
return !source.Any() ? source :
source.Concat(
source
.SelectMany(i => selector(i).EmptyIfNull())
.SelectManyRecursive(selector)
);
}
public static IEnumerable<T> EmptyIfNull<T>(this IEnumerable<T> source)
{
return source ?? Enumerable.Empty<T>();
}
}
}