A free, once-weekly Scala news flash. Easy to unsubscribe. Goes out every Thursday.
September 12th, 2019, ISSUE 291

READING

Squeezing extra productivity out of Ammonite Scala REPL

How to run code snippets in a smooth way?
Krzysztof Ciesielski (@kpciesielski)
Akka family build infrastructure

An overview of some sbt configurations used across Alpakka, Alpakka Kafka and other Akka family projects.
Akka Team (@akkateam)
Learning Akka Typed from Classic

Step-by-stepp Akka lesson on the original Actor APIs.
Akka Team (@akkateam)
On Eliminating Error in Distributed Software Systems

An expansion of What Lies Between: The Challenges of Operationalising Microservices talk from QCon London 2019.
Colin Breck (@breckcs)
Error Handling in Functional Applications - from Monad Transformers to ZIO

Finding the best solution for real-world problems.
Assen Kolov (@kolov)
Make your program testable

It’s important to test the code...
Wiem Zine (@WiemZin)
Type erasure

So, how does the Parallel change not break bincompat?
Travis Brown (@travisbrown)
Cats Effect 3

The proposal for Cats Effect 3 and general overview of Cats Effect.
Daniel Spiewak (@djspiewak)
Introducing sbt-make

An sbt plugin that adds syntax to write make style incremental tasks directly in a build.sbt file.
Ethan Atkins (@_ethan_atkins)
Comparing Performance between Apache Spark and PySpark

Which one is faster?
Sahand Faraz Zarrinkoub
Writing Custom Wart for Scala

An introduction to WartRemover.
Tapan Vaishnav
Syto - pure Scala library for filter design/implementation and digital signal processing

A bridge between Spark Scala logic and Python's Scipy.
Oleksandr Tarasenko

PRESENTATIONS

The "real programmer" myth

How to hire a developer who will save your project?
Maciej Gorywoda (@makingthematrix)
Getting started with Ammonite - A Modernized Scala REPL

In this video we will install and play around with the Ammonite REPL, which is an alternative to the scalac REPL.
DevInsideYou (@DevInsideYou)

EVENTS

Scala.sphere.it, Kraków, Poland, October 7th-8th

Use special promo code 'media-partner-at-sphere.it' for a 20% discount.
ScalaSphere (@ScalaSphere)
Lambda World, Cádiz, Spain, October 17th - 18th

Use our link to get a special discount for Scala Times readers!
Lambda World (@lambda_world)
Code Mesh, London, November 7th - 8th

Get your tickets now!
CodeMesh (@CodeBEAMio)
BeeScala, Ljubljana, Slovenia, November 21st - 21rd

Don't miss your ticket for this unique conference!
BeeScala (@BeeScalaConf)
CFP for ScalaConf.ru, Moscow, Russia, November 26th

Don't miss the CFP deadline which is September 26th!
ScalaConf.ru
Lambda Days, February 13th -14th 2020, Kraków, Poland

Call for talks and very early bird tickets are both open!
Lambda Days (@LambdaDays)

RELEASES

Scala 2.12.10

Shortly, a few improvements have been done: fixed regression in large string interpolations with non-String typed splices and classpath when JARs have 'a.b' entries beside 'a/b and reverted "Generate shallower ASTs in pattern translation".
Scala Lang Team
Alpakka Kafka 1.1.x

The release changes the internals of how offset commits are sent to the Kafka broker.
Akka Team (@akkateam)
zio/delegate

This package defines an annotation and a typeclass that simplify working with mixins and proxies in scala.
ZIO Team
Cats 2.0.0

Version 2.0.0 includes two major pull requests: Infer dependent parameter in NonEmpty/ParallelTests/Laws and Remove unused type parameter for Parallel instances.
Typelevel (@typelevel)
Monix 3.0.0

The latest release with several updates, e.g.: to Cats and Cats-Effect 2.0.0 and Minitest to 2.7.0.
Monix (@monix)
fs2 2.0.0

Functional Streams for Scala. This release features support for Cats 2.0.0 and Cats Effect 2.0.0.
Functional-Streams-for-Scala Team

VARIA

Scala Times banners?

Want one? Click here
THE INTERNET
Scala Times stickers?

Want one? Let us know or tweet @scalatimes.
THE INTERNET
Scala experts?

Need some? SoftwareMill is here, ready to talk and dive deep into your code.
SoftwareMill





  1. Scala Times Issue #314

    Using Dotty Union types with Akka Typed. My FP Journey. Creating a dead simple CountDownLatch with ZIO. ZIO STM: CountDownLatch in two lines. 2019 Scala Developer Survey.


  2. Scala Times Issue #313

    Building Serverless Scala Services with GraalVM. Alpakka Kafka 2.0 Released | @lightbend. Haskell for impatient Scala developer: Getting into speed. Building useful Scalacheck Generators. Easily create New Sync Types with ZIO STM.


  3. Scala Times Issue #312

    Happy eyeballs algorithm using ZIO. How (not) to use shapeless for cross-layer conversions in Scala. So you want to compose some functions. RESTful error handling with Akka HTTP and the library “endpoints”. MUnit is a new Scala testing library · MUnit.


  4. Scala Times Issue #311

    Introducing error reporting in optics. GraphQL in Scala with Caliban - Part 1. Tidying up your SBT file with Scala. Dependency injection with Reader Monad in Scala. Etcd watch API integration with scala and cats-effect.


  5. Scala Times Top Links of 2019

    January: Scala Best Practices. February: Is your Scala object always a singleton?. April: Did Functional Programming get it wrong?. May: The little gems of Scala standard library. June: The Evolution of a Scala Programmer.


  6. Scala Times Issue #310

    Git hooks in Scala projects  - the easy way!. Testing Doobie programs. Implementing typeclasses in Scala I. Effective testing with ZIO Test. Akka Streams: error handling in event processing pipelines.


  7. Scala Times Issue #309

    Towards more functional Play — Part 2. TMWL’ Dec 19 — Scala 3 overview, Scala hacks and DevOps hints. Scala etcd client with etcd4s and cats-effects. Boilerplate-free type class definition. GCP Cloud Functions with Scala.js in 10 lines(ish).


  8. Scala Times Issue #308

    Towards more functional Play  -  Part 1. ZIO environment meets constructor-based dependency injection. How-to run tests in parallel with sbt. Learn myself some Scala 3, episode 4: strict equality. 5 pitfalls to avoid when starting to work with ZIO.


  9. Scala Times Issue #307

    Standardizing IO Interfaces for Scala Libraries. WebSocket Streaming with Scala. State of Monocle. Scala tooling in 2019. How to Work with Scala Collections in Java.


  10. Scala Times Issue #306

    2019 Scala Developer Survey . Lessons Learned Building a Van Laarhoven Lens Library. A Glossary of Functional Programming. Tips for moving from tut to mdoc. Notes on Category Theory in Scala 3 (Dotty).


  11. Scala Times Issue #305

    Beyond Liskov: Type Safe Equality in Scala. Scala 2 Roadmap Update: the Road to Scala 3. Explicit nulls are in!. Functional Scala London 2019: Day 1. Leveraging Monoids for More Powerful Summarization.


  12. Scala Times Issue #304

    Akka references serialization with Protobufs (up to Akka 2.5). TMWL November’19 — ScalaTest, Medusa, PW-Sat2 cubesat. Implement your future with ZIO. Decouple the Program from its Implementation with ZIO modules. ZIO environment and modules pattern: zio, scala.js, react, query management.


  13. Scala Times Issue #303

    Write your own micro BDD test framework in one day. Monoid in the Category of Endofunctors. Introducing Scala Server Toolkit. How to write a command-line application with ZIO. Picking a Languages for Introductory CS  - The Argument Against Python.


  14. Scala Times Issue #302

    Regexp Replacement via Function in Java/Scala. Rationality in a Natural World: Arithmetic at the Type-Level. Transforming Data with Embedded Spark. Migrate a service getting 200KQPS from Jackson to Circe. Scala Type Classes comparison.


  15. Scala Times Issue #301

    Functors  - From Category Theory into Cats. Tour of Akka Typed: Cluster Sharding. The Future.await(s) for no one. Service architecture in Scala. Streaming the last few minutes from Kafka using Akka Streams.


  16. Scala Times Issue #300

    How an Optimizing Compiler Works. TMWL October’19  - Scala Steward, DB index and a React hack. Working with HTTP in Polynote. How I learned to stop worrying and love FP in Scala. A real life example of isomorphisms in Scala: POST request.


  17. Scala Times Issue #299

    Kleisli Category - From theory to Cats. Presto with Doobie. Lambda World 2019. Speeding up time with Zio TestClock. Simulating IoT Events - with Zio Streams.


  18. Scala Times Issue #298

    Scala application lifecycle, from pure Scala to FS2. Top 5 things that slow down your Scala build - Triplequote. ZIO, Http4s, Auth, Codecs and zio-test. Magnolia typeclass generation for Avro. Bird Operator in Scala.


  19. Scala Times Issue #297

    Websockets in Scala using sttp. Vim with Dotty (using coc vim). Sizeof in Scala. Scala Classes - Syntax, Declaration, Use case, Examples. How to structure your Scala application?.


  20. Scala Times Issue #296

    Travis Continuous deployment for your open source library. Publish open source project to Maven with Sonatype. My Way to Scala - part 1. Scala Tuples - Syntax, Declaration, Use case, Examples. Better management of transitive dependencies and conflicts.


  21. Scala Times Issue #295

    Tour of Akka Typed: Event Sourcing. Optional Is the New Mandatory. Visitors - a tale of generalization. Working with Databases using Scala and Quill. Proving Primality with GADTs.


  22. Scala Times Issue #294

    Scraping Websites using Scala and Jsoup. A quiet, attractive new programming language. Domain-driven event sourcing with Akka Typed. Crushing Design Patterns! - Chain of responsibility (Scala). Crushing Design Patterns! - Unnecessary Patterns.


  23. Scala Times Issue #293

    Painlessly passing message context through Akka Streams. Simple Web and Api Servers with Scala. From @Transactional to type-safe, reasonable transactions. 3 Layer Scala Cake. Illustrated guide to Types, Sets and Values.


  24. Scala Times Issue #292

    Human-readable case class diffs. Cats 2.0 migration guide. Top 10 Scala Libraries For Data Science. Kenji Yoshida receives community award. Kelley Robinson receives community award.


  25. Scala Times Issue #291

    Squeezing extra productivity out of Ammonite Scala REPL. Akka family build infrastructure. Learning Akka Typed from Classic. On Eliminating Error in Distributed Software Systems. Error Handling in Functional Applications - from Monad Transformers to ZIO.


Organizing an event?
Promote it with
Scala Times.
The Scala Times reader?
Get a banner!
Got a tip? Send it in!
Follow us on Twitter.
Curated by SoftwareMill.
We are hiring.
And taking on projects.