raulraja

package demo

import arrow.core.Either
import arrow.core.None
import arrow.core.Option
import arrow.core.Some
import arrow.core.continuations.Raise
import arrow.core.continuations.effect
import arrow.core.continuations.either
import arrow.core.continuations.toEither

plamentotev

Hello, Diagrams!

GitHub recently added support for including Mermaid diagrams in Markdown files. The good news is that it works for AsciiDoc files as well. Here is an example:

sequenceDiagram
    participant Alice
    participant Bob

mpilquist

// Save as ~/.ammonite/predef.sc
// To use fs2 from ammonite repl, type `load.fs2` from repl prompt.
// You'll get all fs2 & cats imports, ContextShift and Timer instances
// for IO, and a globalBlocker

import $plugin.$ivy.`org.typelevel:::kind-projector:0.11.0`

if (!repl.compiler.settings.isScala213)
  repl.load.apply("interp.configureCompiler(_.settings.YpartialUnification.value = true)")

MichaelDrogalis

I've been working with Apache Kafka for over 7 years. I inevitably find myself doing the same set of activities while I'm developing or working with someone else's system. Here's a set of Kafka productivity hacks for doing a few things way faster than you're probably doing them now. 🔥

• Show me all my Kafka topics and their partitions, replicas, and consumers
• Show me the contents of a topic
• Create a Kafka topic
• Produce messages to a Kafka topic
• Validate the schema of messages before producing to a topic
• Do all of this at a distance

Get the tools

StephenFluin

# NVM
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
nvm install 10

# Yarn
curl -o- -L https://yarnpkg.com/install.sh | bash
export PATH="$HOME/.yarn/bin:$HOME/.config/yarn/global/node_modules/.bin:$PATH"

peti

This NixOS code ensures that the system provide version-specific $LOCALE_ARCHIVE environment variables to mitigate the effects of NixOS/nixpkgs#38991.

To deploy it, copy the file into your /etc/nixos folder using a file name like multi-glibc-locale-paths.nix. Then edit your configuration.nix file to contain the attribute:

imports = [ ./multi-glibc-locale-paths.nix ];

ntamvl

Install Multiple Java Versions on macOS High Sierra

Install Homebrew Cask

On Mac, Homebrew is the de-facto package manager, and Homebrew Cask is the app manager. I’m going to use Cask to install Java 7 and 8.

Install Homebrew Cask first if you haven’t:

brew update
brew tap caskroom/cask

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.

tkcranny

-- Adapted from these sources:
-- http://peterdowns.com/posts/open-iterm-finder-service.html
-- https://gist.github.com/cowboy/905546
-- https://gist.github.com/ttimasdf/7bb02ed419db4b472b534e1a57008a3b
-- 
-- Modified to work with files as well, cd-ing to their container folder
on run {input, parameters}
	tell application "Finder"
		set my_file to first item of input
		set is_folder to (do shell script "file -b " & quoted form of (POSIX path of my_file))

alexandru

import scalaz._
import scalaz.concurrent.Task

def signal(i: Int): Task[Int] = 
  Task.async[Int] { cb => cb(\/-(i)) }

def loop(n: Int, acc: Int): Task[Int] =
  signal(acc + n).flatMap { x => 
    if (n <= 0) Task.now(acc) 
    else loop(n-1, x)