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