Daniel Hegner da9l

Setup Raspbian Buster

I'm using debian 10 as my daily so these are *nix commands. Mac should work with these too but you're on your own if you're using Windows. Goal for me is to make a headless raspberry pi I can SSH into and connect to my network using Ethernet. You should be comfortable in command line if you choose to follow this guide.

Go to https://www.raspberrypi.org/downloads/raspbian and download Raspbian lite archive
unzip the image
Plug in sdcard. Run lsblk to see drives and mount points. Likely, the sdcard will show up in /dev/sda or /dev/sdb and may have some partitions like /dev/sda1 and /dev/sda2.
If partitions are mounted, unmount all of them. Ex: umount /dev/sda1 and umount /dev/sda2
Copy the raspbian image to the sdcard with sudo dd if=RASPBIAN_IMAGE_FILE.img of=/dev/sda bs=4M
Run sync to ensure the written contents are flushed
OPTIONAL: To start ssh server on boot, Unplug sdcard and reinsert to remount new partitions. You'll have two with raspbian.

[F#] Implementing Coroutines (async/await) using continuations

Coroutines or async/await is not a new concept as it was named in 1958 by Melvin Conway. Coroutines had support in languages such as Simula(1962), Smalltalk(1972) and Modula-2(1978) but I think one can argue that coroutines came into mainstream with C# 5(2012) when Microsoft added async/await to C#.

The problem with subroutines

A thread can only execute a single subroutine at a time as a subroutine starts and then runs to completion. In a server environment subroutines can be problematic as in order to service connections concurrently we would usually would start a thread per connection, this was the idiom a few years ago. A thread depending on the operating system and settings needs about 1 MiB of user stack space meaning 1,024 threads needs 1 GiB of for just user stack space. In addition there's the cost of kernel stack space, book-keeping and scheduling of threads. This drives cost of VM/hardwa


	//Builder represeting only one entity in DSL

	type Child1State = {SomeState : string}

	type Child1Builder () =

	[<CustomOperation("set_state")>]
	member __.SetState (st, x) = {st with SomeState = x}

	source /etc/bash_completion.d/git-prompt
	GIT_PS1_SHOWCOLORHINTS=true
	GIT_PS1_SHOWDIRTYSTATE=true
	PROMPT_COMMAND='__git_ps1 "${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w" "\$\[\033[00m\] "'

	Remove-ItemProperty -Path HKLM:\Software\Microsoft\Fusion -Name ForceLog
	Remove-ItemProperty -Path HKLM:\Software\Microsoft\Fusion -Name LogFailures
	Remove-ItemProperty -Path HKLM:\Software\Microsoft\Fusion -Name LogResourceBinds
	Remove-ItemProperty -Path HKLM:\Software\Microsoft\Fusion -Name LogPath

	<#
	.Synopsis

	Returns the install .NET Framework versions.

	.Description

	The script looks through the registry using the notes from the below
	MSDN links to determine which versions of .NET are installed.

	/*
	d8888 .d8888b. 888b 888
	d88888 d88P Y88b 8888b 888
	d88P888 888 888 88888b 888
	.d8888b d88P 888 888 888Y88b 888
	88K d88P 888 888 888 Y88b888
	"Y8888b. d88P 888 888 888 888 Y88888
	X88 d8888888888 Y88b d88P 888 Y8888
	88888P' d88P 888 "Y8888P" 888 Y888

	namespace Newtonsoft.Json.Converters

	open Microsoft.FSharp.Reflection
	open Newtonsoft.Json
	open System

	type IdiomaticDuConverter() =
	inherit JsonConverter()

	[<Literal>]

	#requires -version 2.0
	Add-Type @"
	public class Shift {
	public static int Right(int x, int count) { return x >> count; }
	public static uint Right(uint x, int count) { return x >> count; }
	public static long Right(long x, int count) { return x >> count; }
	public static ulong Right(ulong x, int count) { return x >> count; }
	public static int Left(int x, int count) { return x << count; }
	public static uint Left(uint x, int count) { return x << count; }
	public static long Left(long x, int count) { return x << count; }