Esprima.Ast.List<T> vs System.Collections.Generic.List<T>

Benchmark.cs

using BenchmarkDotNet.Attributes;

namespace Esprima.Benchmark
{
    [MemoryDiagnoser]
    public class ListBenchmark
    {
        private const int Size = 10_000;
        private Ast.List<int> _astList;
        private System.Collections.Generic.List<int> _bclList;

        [GlobalSetup]
        public void OneTimeSetup()
        {
            _astList = new Ast.List<int>();
            for (var i = 0; i < Size; ++i) _astList.Add(i);

            _bclList = new System.Collections.Generic.List<int>();
            for (var i = 0; i < Size; ++i) _bclList.Add(i);
        }

        [Benchmark]
        public Ast.List<int> AstListAdd()
        {
            var items  = new Ast.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);

            return items;
        }

        [Benchmark]
        public System.Collections.Generic.List<int> BclListAdd()
        {
            var items = new System.Collections.Generic.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);
            return items;
        }

        [Benchmark]
        public int AstListFor()
        {
            var sum = 0;
            for (var i = 0; i < _astList.Count; ++i) sum += _astList[i];

            return sum;
        }

        [Benchmark]
        public int BclListFor()
        {
            var sum = 0;
            for (var i = 0; i < _bclList.Count; ++i) sum += _bclList[i];

            return sum;
        }

        [Benchmark]
        public int AstListAddAndFor()
        {
            var items = new Ast.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);

            var sum = 0;
            for (var i = 0; i < items.Count; ++i) sum += items[i];

            return sum;
        }

        [Benchmark]
        public int BclListAddAndFor()
        {
            var items = new System.Collections.Generic.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);

            var sum = 0;
            for (var i = 0; i < items.Count; ++i) sum += items[i];

            return sum;
        }


        [Benchmark]
        public int AstListAddAndForEach()
        {
            var items = new Ast.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);

            var sum = 0;
            foreach (var t in items) sum += t;

            return sum;
        }

        [Benchmark]
        public int BclListAddAndForEach()
        {
            var items = new System.Collections.Generic.List<int>();
            for (var i = 0; i < Size; ++i) items.Add(i);

            var sum = 0;
            foreach (var t in items) sum += t;

            return sum;
        }

        [Benchmark]
        public int AstListForEach()
        {
            var sum = 0;
            foreach (var t in _astList) sum += t;

            return sum;
        }

        [Benchmark]
        public int BclListForEach()
        {
            var sum = 0;
            foreach (var t in _bclList) sum += t;

            return sum;
        }
    }
}

Results.md

BenchmarkDotNet=v0.11.3, OS=Windows 10.0.17763.195 (1809/October2018Update/Redstone5)
Intel Core i7-6820HQ CPU 2.70GHz (Skylake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=2.2.101
  [Host]     : .NET Core 2.1.6 (CoreCLR 4.6.27019.06, CoreFX 4.6.27019.05), 64bit RyuJIT
  DefaultJob : .NET Core 2.1.6 (CoreCLR 4.6.27019.06, CoreFX 4.6.27019.05), 64bit RyuJIT

Method	Mean	Error	StdDev	Gen 0/1k Op	Gen 1/1k Op	Gen 2/1k Op	Allocated Memory/Op
AstListAdd	36.29 us	0.0758 us	0.0709 us	31.1890	-	-	131368 B
BclListAdd	26.62 us	0.0272 us	0.0227 us	31.2195	7.7820	-	131408 B
AstListFor	10.15 us	0.0300 us	0.0280 us	-	-	-	-
BclListFor	11.87 us	0.0126 us	0.0112 us	-	-	-	-
AstListAddAndFor	43.18 us	0.1492 us	0.1395 us	31.1890	-	-	131368 B
BclListAddAndFor	32.44 us	0.0319 us	0.0283 us	31.1890	-	-	131408 B
AstListAddAndForEach	90.32 us	0.1534 us	0.1360 us	31.1279	-	-	131416 B
BclListAddAndForEach	47.44 us	0.1276 us	0.1131 us	31.1890	-	-	131408 B
AstListForEach	62.91 us	0.2102 us	0.1967 us	-	-	-	48 B
BclListForEach	22.26 us	0.0281 us	0.0263 us	-	-	-	-