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

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) 

mandubian

/**
  * In classic Scala implementation of hierarchies of Category theory laws (scalaz/cats), the dependency between
  * different laws is encoded using inheritance (https://github.com/typelevel/cats/blob/master/core/src/main/scala/cats/Monad.scala#L14)
  *
  * This approach creates well-known issues: for example, a Monad is able to _derive_ an Applicative.
  * So sometimes, you don't have the Applicative you want but the one derived from the Monad or it doesn't
  * compile because you have 2 Applicatives in your implicit scope.
  *
  * Alois Cochard has proposed a new model to represent that in (scato project)[https://github.com/aloiscochard/scato] or
  * (scalaz/8.0.x)[https://github.com/scalaz/scalaz/blob/series/8.0.x/base/src/main/scala/typeclass/Monad.scala] branch.