SO76611515

gistfile1.cs

void Main()
{
	var summary = BenchmarkRunner.Run<Test>();
}

public class Test
{
	[Benchmark]
	public void Max()
	{
		TestData.GroupBy(a => new { a.B, a.C })
		.Select(g => new A { B = g.Key.B, C = g.Key.C, D = g.Max(a => a.D), E = g.Max(a => a.E) }).ToList();
	}
	
	[Benchmark]
	public void Any()
	{	
		TestData.GroupBy(a => new { a.B, a.C })
		.Select(g => new A { B = g.Key.B, C = g.Key.C, D = g.Any(a => a.D), E = g.Any(a => a.E) }).ToList();
	}

	[Benchmark]
	public void Aggregate()
	{
		TestData.GroupBy(a => new { a.B, a.C })
		.Select(g => g.Aggregate(new A { B = g.Key.B, C = g.Key.C }, (ar, a) => { ar.D |= a.D; ar.E |= a.E; return ar; })).ToList();
	}

	[Benchmark]
	public void AggregateUntil()
	{
		TestData.GroupBy(a => new { a.B, a.C })
		.Select(g => g.AggregateUntil(new A { B = g.Key.B, C = g.Key.C }, (ar, a) => { ar.D |= a.D; ar.E |= a.E; return (ar.D && ar.E, ar); })).ToList();
	}

	List<A> TestData { get; } = new List<A> 
	{ 
		//first D and E are tru so Any will return immediately
		new A { B = 1, C = 1, D = true, E = true },
		new A { B = 1, C = 2, D = true, E = true },
		new A { B = 1, C = 3, D = true, E = true },
		new A { B = 1, C = 4, D = true, E = true },
		new A { B = 1, C = 5, D = true, E = true },
		new A { B = 1, C = 6, D = true, E = true },
		new A { B = 1, C = 7, D = true, E = true },

		//second
		new A { B = 1, C = 1, E = true },
		new A { B = 1, C = 2, E = true }
	};
}

public class A
{
	public int B { get; set; }
	public int C { get; set; }
	public bool D { get; set; }
	public bool E { get; set; }
}



static class Ext
{
	public static TAccumulate AggregateUntil<TSource, TAccumulate>(this IEnumerable<TSource> source, TAccumulate seed, Func<TAccumulate, TSource, (bool, TAccumulate)> func)
	{
		foreach(var item in source)
		{
			var res = func(seed, item);
			if(res.Item1)
				return res.Item2; // fast lane
			seed = res.Item2;
		}
		return seed;
	}
}

net48.txt

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22621
12th Gen Intel Core i7-12700H, 1 CPU, 20 logical and 14 physical cores
  [Host]     : .NET Framework 4.8 (4.8.9166.0), X86 LegacyJIT
  DefaultJob : .NET Framework 4.8 (4.8.9166.0), X86 LegacyJIT


|         Method |       Mean |   Error |  StdDev |
|
--------------- |-----------:|--------:|--------:|
|            Max | 1,434.2 ns | 7.55 ns | 7.06 ns |
|            Any |   927.8 ns | 6.60 ns | 5.85 ns |
|      Aggregate |   774.2 ns | 6.25 ns | 5.85 ns |
| AggregateUntil |   797.0 ns | 5.62 ns | 5.25 ns |

net6.txt

BenchmarkDotNet=v0.13.5, OS=Windows 11 (10.0.22621.1848/22H2/2022Update/SunValley2)
12th Gen Intel Core i7-12700H, 1 CPU, 20 logical and 14 physical cores
.NET SDK=7.0.304
  [Host] : .NET 6.0.18 (6.0.1823.26907), X64 RyuJIT AVX2


|         Method |     Mean |   Error |  StdDev |
|--------------- |---------:|--------:|--------:|
|            Max | 841.0 ns | 8.55 ns | 8.00 ns |
|            Any | 780.9 ns | 3.27 ns | 3.06 ns |
|      Aggregate | 652.6 ns | 4.06 ns | 3.60 ns |
| AggregateUntil | 639.1 ns | 4.86 ns | 4.54 ns |