TonioGela

//> using scala "3.2.1"
//> using lib "com.monovore::decline-effect::2.4.1"
//> using lib "co.fs2::fs2-io::3.4.0"
//> using packaging.output "mkString"
//> using platform "scala-native"
//> using nativeMode "release-fast"
//> using nativeGc "none"

import cats.effect.*
import cats.effect.std.*

chaotic3quilibrium

Effective Scala Case Class Patterns

Version: 2022.03.02

Available As

quelgar

Every Argument for Static Typing Applies to Typed Errors

Think of all the arguments you've heard as to why static typing is desirable — every single one of those arguments applies equally well to using types to represent error conditions.

An odd thing I’ve observed about the Scala community is how many of its members believe that a) a language with a sophisticated static type system is very valuable; and b) that using types for error handling is basically a waste of time. If static types are useful—and if you like Scala, presumably you think they are—then using them to represent error conditions is also useful.

Here's a little secret of functional programming: errors aren't some special thing that operate under a different set of rules to everything else. Yes, there are a set of common patterns we group under the loose heading "error handling", but fundamentally we're just dealing with more values. Values that can have types associated with them. There's absolutely no reason why the benefits of static ty

maxisam

set -e, -u, -o, -x pipefail

The set lines

• These lines deliberately cause your script to fail. Wait, what? Believe me, this is a good thing.
• With these settings, certain common errors will cause the script to immediately fail, explicitly and loudly. Otherwise, you can get hidden bugs that are discovered only when they blow up in production.

• set -euxo pipefail is short for:

set -e
set -u

TheSherlockHomie

Updating expired GPG keys and their backup 🔑🔐💻

I use a GPG key to sign my git commits.

An error like this one might be a sign of an expired GPG key.

error: gpg failed to sign the data fatal: failed to write commit object

laughedelic

Some of these practices might be based on wrong assumptions and I'm not aware of it, so I would appreciate any feedback.

1. avoiding some dependency conflicts:

   • install sbt-explicit-dependencies globally in your ~/.sbt/{0.13,1.0}/plugins/plugins.sbt
   • run undeclaredCompileDependencies and make the obvious missing dependencies explicit by adding them to libraryDependencies of each sub-project
   • (optionally) run unusedCompileDependencies and remove some obvious unused libraries. This has false positives, so ; reload; Test/compile after each change and ultimately run all tests to see that it didn't break anything
   • (optionally) add undeclaredCompileDependenciesTest to the CI pipeline, so that it will fail if you have some undeclared dependencies

2. keeping dependencies up to date and resolving conflicts:

   • install sbt-updates globally in your `~/.sbt/{0.13,1.0}/plugins/plugins.

jdegoes

package fpmax

import scala.util.Try
import scala.io.StdIn.readLine

object App0 {
  def main: Unit = {
    println("What is your name?")

    val name = readLine()

gvolpe

Dependency Injection in Functional Programming

There exist several DI frameworks / libraries in the Scala ecosystem. But the more functional code you write the more you'll realize there's no need to use any of them.

A few of the most claimed benefits are the following:

• Dependency Injection.
• Life cycle management.
• Dependency graph rewriting.

henfiber

Europe

• SkinFlint : Price comparison site which has some nice filtering options per switch type etc. Searches for offers in UK, Germany, Poland and Austria
• mykeyboard.eu : Keyboards, keycaps and accessories. Based in Belgium.
• candykeys.com : European Store selling Vortex, Leopold, KBP, Anne Pro keyboards, keycap sets and components (ISO + ANSI). Based in Germany, ships to EU.
• falba.tech : custom wooden bamboo cases, and some acrylic and carbon ones. Switch packs (65 browns at 48EUR). Other parts for the GH60, Atreus, ErgoDox. Also Microcontrollers, diodes, leds etc.
• 42keebs.eu - Mostly PCBs, tools and accessories. Located in Czech Republic.
• KEYGEM : Switches, Keycaps, lubes, cables, DIY kits and deskmats. Based in Germany, ships to the EU and worldwide.
• [Eloquent Clicks - Custom Mechanical Keyboard Store](https://www.eloquen

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.