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January 2nd, 2020, ISSUE 307


Standardizing IO Interfaces for Scala Libraries

Exploration of two interfaces: Writable and Readable - the new standard of Li's OSS.
Li Haoyi (@li_haoyi)
WebSocket Streaming with Scala

How Akka Streams can make life easier.
Duane Bester (@duanebester)
State of Monocle

An experiment with various optics encoding: pair of functions, Van Laarhoven, and profunctor (see LensImpl).
Julien Truffaut (@JulienTruffaut)
Scala tooling in 2019

The highlight of a few of the developments from 2019.
Ólafur Páll Geirsson (@olafurpg)
How to Work with Scala Collections in Java

The short tutorial for Java developers who want to use Scala libraries and need to work with Scala collections.
Uri Bechar
Write Clean and SOLID Scala Spark Jobs

A guide to writing extensible and maintainable Spark jobs that increase the data team’s productivity and guarantee better products.
Ronald Ángel
Currying in Scala: A Useful Example

The usage of the functionality in a programming language.
Kadir Malak
Generic Traits and Classes With Type Parameters And Variance

The exploration of variance.
Knoldus Inc. (@Knolspeak)
Operator overloading in Scala and Kotlin: two slightly different ways

If Scala has a feature, Kotlin probably has that same feature too, right?
Alonso Del Arte
How to use the same Test for different Implementations with ZIO

I think ZIO gives me (as a simple Programmer without Ph.D.) the chance to get to my next level of Functional Programming.
Mocking The Right Way

Using Mockito requires changing how we think about unit tests while removing a lot of boilerplate.
Knoldus Inc.
SPNEGO Token generation

SPNEGO - is a simple and protected negotiation mechanism used by client-server software.
Alexey Novakov (@alexey_novakov)
SBT for the absolute beginner 1 (Basics and dependency Management)

SBT also has its own interactive shell that is run by just calling sbt, commands like run, clean and test can then be directly entered into the shell.
Orji Samuel


Using Tagless Final with laws - Scala tutorial

In this video, you'll learn about the Tagless Final technique and a way to correctly implement and test a Tagless Final algebra in your program.
Jakub Kozłowski (@kubukoz)


Lambda Days, February 13th -14th 2020, Kraków, Poland

Draft paper submission by January 13th.
Lambda Days (@LambdaDays)
ScalaUA, April 3th-4th, 2020 Kyiv, Ukraine

CFP is on! Wholesale 10+ tickets are available till 2020.04.02.
ScalaUA (@ScalaUA_Conf)
Scalar, March 19th-21st, 2020, Warsaw, Poland

Get ready for one of the biggest Scala conferences in Europe!
SoftwareMill (@scalarconf)



A small library to encode event-sourcing patterns using FS2, a streaming library in Scala.
Ryan Peters (@LiquidSloshalot)

An ONNX (Open Neural Network eXchange) API, Code Generator and Backend for Typeful, Numerically Generic, Functional Deep Learning in Scala.
Alex Merritt


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