Atif Aziz atifaziz

What's this?

Found an interesting [comment] in SqlDataReader's source code:

// this block of type specific shortcuts uses RyuJIT jit behaviours to achieve fast implementations of the primitive types
// RyuJIT will be able to determine at compilation time that the typeof(T)==typeof(<primitive>) options are constant
// and be able to remove all implementations which cannot be reached. this will eliminate non-specialized code for

Compiling C to WebAssembly using Clang/LLVM & WASI

These are my notes. See also “[Compiling C to WebAssembly using clang/LLVM and WASI][fda]” by [Frank Denis], which was my starting point.

Assume the following example program in a file called example.c:

#include

	<Query Kind="Program">
	<NuGetReference Version="4.0.0">System.Reactive</NuGetReference>
	<NuGetReference Version="4.5.0">System.Text.Encoding.CodePages</NuGetReference>
	<NuGetReference Version="1.0.0-alpha-20200416" Prerelease="true">WebLinq</NuGetReference>
	<Namespace>System.CodeDom.Compiler</Namespace>
	<Namespace>System.Globalization</Namespace>
	<Namespace>System.Net</Namespace>
	<Namespace>System.Net.Http</Namespace>
	<Namespace>System.Net.Http.Headers</Namespace>
	<Namespace>System.Reactive</Namespace>

	<Query Kind="Program">
	<NuGetReference Version="1.0.0">Kurukuru</NuGetReference>
	<NuGetReference Version="2.2.4">McMaster.Extensions.CommandLineUtils</NuGetReference>
	<NuGetReference Version="11.0.2">Newtonsoft.Json</NuGetReference>
	<Namespace>Kurukuru</Namespace>
	<Namespace>Newtonsoft.Json</Namespace>
	<Namespace>McMaster.Extensions.CommandLineUtils</Namespace>
	<Namespace>System.Threading.Tasks</Namespace>
	<Namespace>System.Net.Http</Namespace>
	</Query>

	using System.IO;

	var fileName = Path.GetRandomFileName();
	Console.WriteLine($"File name: {fileName}");
	Console.WriteLine($"Exists? {File.Exists(fileName)}");
	using (var fs = File.Create(fileName, 4096, FileOptions.DeleteOnClose))
	Console.WriteLine($"Exists? {File.Exists(fileName)}");
	Console.WriteLine($"Exists? {File.Exists(fileName)}");

	using System;

	public class C {
	public void M((bool, object) x) {
	if (x is (true, {} obj)) {
	Console.WriteLine(obj);
	}
	}
	public void N(bool f, object obj) {
	if (f) {

	times = [ '12:00', '10:00', '12:15', '09:30' ]

	// simple way
	// relies on string comparison operators (`<` and `>`)

	sorted = [...times].sort((a, b) => a > b ? 1 : a < b ? -1 : 0)
	// sorted = [ '09:30', '10:00', '12:00', '12:15' ]

	// complicated way
	// - split time on ":" into two parts: hours and minutes

	// This script is related the following blog entry by Mark Seeman titled,
	// "Builder as a monoid":
	//
	// https://blog.ploeh.dk/2020/02/17/builder-as-a-monoid/
	//
	// It demonstrates a simpler approach to avoid the ceremony of "explicit
	// endomorphism" by using merely delegates. It does so by replacing
	// "IEndomorphism<T>" with "Func<T, T>" and then using "+" in lieu of
	// "AppendEndomorphism<T>" to achieve the same effect.
	//

	@echo off
	setlocal
	for /f "usebackq" %%f in (`PowerShell -C "([datetimeoffset](git ls -1 --pretty=%%cI)).ToUniversalTime().ToString('yyyyMMdd''T''HHmm')"`) do set COMMIT_TIMESTAMP=%%f
	if not %ERRORLEVEL%==0 exit /b %ERRORLEVEL%
	call "%~dp0pack.cmd" priv-%COMMIT_TIMESTAMP%
	exit /b %ERRORLEVEL%

	using System;
	using System.IO;
	using SharpLab.Runtime;

	static class X
	{
	public static bool HasFlag(this FileAttributes self, FileAttributes flag) =>
	(self & flag) == flag;

	[JitGeneric(typeof(FileAttributes))]