A free, once-weekly Scala news flash. Easy to unsubscribe. Goes out every Thursday.
June 27th, 2019, ISSUE 280

READING

Comonads for Life

We will look at Comonads, a type class closely related to Monads, firstly from an abstract point of view and progressing to a couple of practical, yet simple, examples of using Comonads for interesting applications.
Justin Heyes-Jones (@justinhj)
TypeSafe journey using Scala

A quick book on Scala Type System.
Harmeet Singh (@singh_harmeet13)
Scala programming language wins SIGPLAN award

According to the SIGPLAN award committee, “Scala is one of the few programming languages from academia that has had a significant impact on the world as well as on programming languages research."
Shapeless' HLists and how to traverse them

Learn how to achieve working sequence and traverse implementations for any HList and any Applicative.
Yannick Heiber
How to work with JSON in Scala

This tutorial introduces you to the basics of working with JSON in a Scala program, using the uPickle library.
Li Haoyi (@li_haoyi)
cleanframes  - data cleansing library for Apache Spark!

cleanframes is a library that aims to automate data cleansing in Spark SQL with help of a generic programming.
Dawid Rutowicz

PRESENTATIONS

Killing the unit test

In this talk, I’ll explain what Property-based testing and Law testing are, and share some concrete examples from the work we do in BigPanda.
Dor Sever (@dor_sever)

EVENTS

LX Scala & Reactive, Lisbon, Portugal, 4th - 5th July

Use promo code scalatimes_ to get a 40% discount for our readers!
LX Scala & Reactive (@lx_scala)
Lambda World, Cádiz, Spain, October 17th - 18th

Use our link to get a special discount for Scala Times readers!
Lambda World (@lambda_world)
BeeScala, Ljubljana, Slovenia, November 21st - 21rd

Don't miss your ticket for this unique conference!
BeeScala (@BeeScalaConf)

RELEASES

http4s-jdk-http-client

JDK 11+ http client implementation for http4s clients.
stateful-serverless

Research into Stateful Serverless With Akka, Knative, and gRPC.
Lightbend (@lightbend)
cats-retry

A library for retrying actions that can fail.
cats-retry contributors
zio-saga

A library that helps to implement Saga Pattern in purely functional way.
Vladyslav Kopaniev

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 #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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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?.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Scala Times Issue #290

    Easy Parallel Programming with Scala Futures. Permutive Community Engineering, August 2019. Key things I picked up while working with Scala. Typing the technical interview in Scala. Why Try? - Scala Error Handling.

  15. Scala Times Issue #289

    Dotty (Scala 3) adoption report: easy so far. Scraping and Storing Crypto-currency Prices with Scala and PostgreSQL. Scala Almost Succeeded. Allow significant indentation syntax. Jailbreak Oozie Spark action.

  16. Scala Times Issue #288

    Bootzooka 2019: functional Scala and React. The Science of Functional Programming book. Scala's isInstanceOf is an Anti-Pattern. A Scala “functional programming style” To-Do List application written with Cats. Minutes of the 13th meeting of the Scala Center, Q2 2019.

  17. Scala Times Issue #287

    When do you need Akka Cluster?. Hangman in FP Scala. Make your Google Spreadsheets Scala-ble. Understanding Monoids using real life examples. Scala in the City, London, Simply Business, August 28th.

  18. Scala Times Issue #286

    Tic-tac-toe in FP Scala. How to create Build Pipelines in Scala. Tour of Akka Typed: Message Adapters, Ask Pattern and Actor Discovery. Promise for better Future. Streaming data with Apache Kafka and Akka Streams.

  19. Scala Times Issue #285

    Monad Transformers and Cats MTL. Ratelimiter4s : A functional rate limiting library. A way out of the Jar Hell. Wrapping impure code with ZIO. XXE Attacks in Scala and Play Framework.

  20. Scala Times Issue #284

    Cross-compiling In Scala. IntelliJ Scala Plugin 2019.2. Introducing Scala Cypher DSL. Tame your config. A rate-limiter in 15 lines of code with cats-effect.

  21. Scala Times Issue #283

    Python vs. Scala: a comparison of the basic commands. Keep your projects up-to-date with Scala Steward. My favorite new features of Scala 2.13 standard library. Implementing a server for the Language Server Protocol. Homegrown Scala Collections: Testing Streams.

  22. Scala Times Issue #282

    Read Pure functional HTTP APIs in Scala | Leanpub. Combining ZIO and Akka to enable distributed FP in Scala. Rethinking Streaming Workloads with Akka Streams: Part II. ES/CQRS the Akka way - Krunoslav Uzelac - Medium. Tour of Akka Typed: Protocols and Behaviors.

  23. Scala Times Issue #281

    Abstracting Over Effect Types. Reusable pre-commit hooks in Scala projects. Functional Highlighting for Functional Programming. Top Link of June: The Evolution of a Scala Programmer. Lambda World, Cádiz, Spain, October 17th - 18th.

  24. Scala Times Issue #280

    Comonads for Life. TypeSafe journey using Scala. Scala programming language wins SIGPLAN award. Shapeless' HLists and how to traverse them. How to work with JSON in Scala.

  25. Scala Times Issue #279

    Thread shifting in cats-effect and ZIO. How to work with HTTP JSON APIs in Scala. ZIO with http4s and doobie. Optimizing CI build times for Scala projects. The False Hope of Tagless-Final in Scala.

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.