Rich Lander richlander

.NET Team member, trail runner, Dad, Husband. He/him

richlander / Program.cs

Last active May 9, 2020 21:29

Environment information

	using System;
	using System.IO;
	using System.Reflection;
	using System.Runtime.InteropServices;
	using static System.Console;

	namespace versioninfo
	{
	class Program
	{

richlander / json-document.cs

Created January 29, 2019 17:21

Sample Usage of JsonDocument and JsonElement

	static double ParseJson()
	{
	const string json = " [ { \"name\": \"John\" }, [ \"425-000-1212\", 15 ], { \"grades\": [ 90, 80, 100, 75 ] } ]";

	double average = -1;

	using (JsonDocument doc = JsonDocument.Parse(json))
	{
	JsonElement root = doc.RootElement;
	JsonElement info = root[1];

richlander / skeleton-ibufferwriter-impl.cs

Created January 29, 2019 17:13

Skeleton IBufferWriter<byte> Implementation

	public class ArrayBufferWriter : IBufferWriter<byte>, IDisposable
	{
	private byte[] _rentedBuffer;
	private int _written;

	public ArrayBufferWriter(int initialCapacity)
	{
	// TODO: argument validation

	_rentedBuffer = ArrayPool<byte>.Shared.Rent(initialCapacity);

richlander / json.cs

Created January 29, 2019 17:11

Sample usage of Utf8JsonWriter

	static int WriteJson(IBufferWriter<byte> output, long[] extraData)
	{
	var json = new Utf8JsonWriter(output, state: default);

	json.WriteStartObject();

	json.WriteNumber("age", 15, escape: false);
	json.WriteString("date", DateTime.Now);
	json.WriteString("first", "John");
	json.WriteString("last", "Smith");

richlander / SoftwareFallback-take-pointer.cs

Created January 29, 2019 17:10

Taking pointer from unmanaged constructed type

	Vector256<int> SoftwareFallback(int x)
	{
	var result = Vector256<int>.Zero;
	((int*)(&result))[0] = x;
	return result;
	}

richlander / SoftwareFallback-UnSafe.cs

Last active January 29, 2019 17:11

Using Unsafe APIs

	Vector256<short> SoftwareFallback(short x)
	{
	var result = Vector256<short>.Zero;
	Unsafe.WriteUnaligned(ref Unsafe.As<Vector256<short>, byte>(ref result), value);
	return result;
	}
	// https://github.com/dotnet/coreclr/blob/57fd77e6f8f7f2c37cc5c3b36df3ea4f302e143b/src/System.Private.CoreLib/shared/System/Runtime/Intrinsics/Vector256.cs#L1303

richlander / SoftwareFallback-take-pointer.cs

Created January 29, 2019 17:08

Taking a pointer to an unmanaged constructed type

	Vector256<double> SoftwareFallback(double x)
	{
	var pResult = stackalloc double[4]
	{
	x,
	x,
	x,
	x,
	};

richlander / SoftwareFallback-UnSafe.cs

Created January 29, 2019 17:05

Using Unsafe API

	Vector256<double> SoftwareFallback(double x)
	{
	var pResult = stackalloc double[4]
	{
	x,
	x,
	x,
	x,
	};

richlander / switch-expression.cs

Created January 29, 2019 17:03

C# 8 Switch Expression Tuple Deconstruction and Positional Pattern

	static State ChangeState(State current, Transition transition, bool hasKey) =>
	(current, transition) switch
	{
	(Opened, Close) => Closed,
	(Closed, Open) => Opened,
	(Closed, Lock) when hasKey => Locked,
	(Locked, Unlock) when hasKey => Closed,
	_ => throw new InvalidOperationException($"Invalid transition")
	};

richlander / switch-expression.cs

Created January 29, 2019 17:01

C# 8 Switch Expression

	static string Display(object o) => o switch
	{
	Point { X: 0, Y: 0 } => "origin",
	Point { X: var x, Y: var y } => $"({x}, {y})",
	_ => "unknown"
	};