Martynas Mickevičius 2m

Reboot to {OS}

This a collection of notes and files used in my quest to create "Reboot to Windows" and "Reboot to Linux" scripts (and desktop shortcuts) for Linux and Windows respectively that automatically reboot my system and instruct rEFInd to auto-select the appropriate OS entry.

General Information

The key for achieving this is to modify the EFI Variable PreviousBoot with GUID 36d08fa7-cf0b-42f5-8f14-68df73ed3740, which rEFInd uses to store the last entry selected in the menu and, if using the + default entry, will be used to select the default OS. By doing this, we trick rEFInd into booting the OS we choose without having to be physically there to press the keyboard.

Akka Streams Backpressure Gauge

Measures if there is backpressure on an Akka Stream at the given stage.

Motivation

When an Akka Stream doesn't perform as intended, it is difficult to tell where the bottleneck is, since all stages operate at the same rate (see e.g. here ).

So when things are not fast as expected, this pressure gauge can help you to narrow down on the slow stage. Imagine

Summer of Usability

Dear Community

We from the Scala team at Lightbend have decided to take some time this summer to work on usability improvements that are always falling through the cracks while we're busy working on the hard features of the next Scala release. Here is a summary of our project proposals.

REPL usability improvements

@som-snytt already implemented the JLine 3 upgrade (scala/scala#8036) which gives multi-line history and editing. We are planning to add further improvements (many of them pioneered by Ammonite and/or the Dotty REPL) on top of this, for example syntax highlighting and import library dependencies.

Advent of Code 2019, in Unison

Spoilers for Advent of Code 2019 follow.

Day 1: The Tyranny of the Rocket Equation

Fuel required to launch a given module is based on its mass. Specifically, to find the fuel required for a module, take its mass, divide by three, round down, and subtract 2.

This describes a simple function. There seems to be an oversight in the problem statement that modules with very low mass have a negative fuel requirement. I'm going to assume that's not right, and that instead of integer subtraction, we want natural number subtraction (sometimes called "monus"). In Unison, we can use the Nat type instead of integers, so we don't have to consider negatives. The subtraction operation is called drop:

	/*
	Copyright 2018 Viktor Klang

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software

	#!/bin/sh
	#
	# !!! IMPORTANT !!!
	# As of 2017-12-14, pacaur is unmaintained (https://bbs.archlinux.org/viewtopic.php?pid=1755144#p1755144)
	# For alternatives see the arch wiki: https://wiki.archlinux.org/index.php/AUR_helpers#Active
	# pacaur seems to get occasional updates to fix breaking changes due to pacman updates though.
	#
	# If you are new to arch, I encourage you to at least read and understand what
	# this script does befor blindley running it.
	# That's why I didn't make a one-liner out of it so you have an easier time

	/* sbt -- Simple Build Tool
	* Copyright 2011 Mark Harrah, Eugene Yokota
	*/
	package sbt
	package myinspect

	import java.io.File

	import Def.{ScopedKey, compiled, flattenLocals}

	/**
	* Copyright (C) 2018 Lightbend Inc. <http://www.lightbend.com>
	*/
	package akka.stream.stage

	import scala.collection.immutable
	import scala.concurrent.duration.FiniteDuration

	import akka.NotUsed
	import akka.annotation.InternalApi

	/* library dependecies
	"org.xerial" % "sqlite-jdbc" % "3.23.1",
	"org.tpolecat" %% "doobie-core" % "0.5.3",
	"org.tpolecat" %% "doobie-hikari" % "0.5.3", // HikariCP transactor.
	"org.tpolecat" %% "doobie-specs2" % "0.5.3", // Specs2 support for typechecking statements.
	"org.tpolecat" %% "doobie-scalatest" % "0.5.3", // ScalaTest support for typechecking statements.
	*/
	object TryDoobie extends App {

	import doobie._

	const MY_DOMAIN = "agodrich.com"
	const START_PAGE = "https://www.notion.so/gatsby-starter-notion-2c5e3d685aa341088d4cd8daca52fcc2"
	const DISQUS_SHORTNAME = "agodrich"

	addEventListener('fetch', event => {
	event.respondWith(fetchAndApply(event.request))
	})

	const corsHeaders = {
	"Access-Control-Allow-Origin": "*",