A free, once-weekly Scala news flash. Easy to unsubscribe. Goes out every Thursday.
April 11th, 2019, ISSUE 269


Scalar 2019 whiteboard voting

Is tagless final dead? What's your favourite Scala effect wrapper? What's the biggest Scala problem? See the results!
Adam Warski (@adamwarski)
38 lines of code towards better data validation in Scala

In this article I will show the problem with the validation over nested monads, when the code explodes with boilerplate and it is difficult to separate different levels of abstraction.
Jakub Dzikowski
Scala: Internals and Intermediates

In this guide, we aim to explore Scala’s toolchain and internals.
Alex Heres
How the Lagom framework enables scalable, reactive Microservices in Java and Scala

The pitch for the Lagom framework is that its programming model and architecture allow developers to write microservices that effectively scale across large deployments, that provide desirable application quality-of-life characteristics such as robust error tolerance and application responsiveness, and that take full advantage of the today’s massively-multicore computer hardware.
Jonathan West
Beyond unit tests: an intro to property and law testing in Scala

Learn about the power of property-based testing and law testing.
Daniel Sebban (@dsebban)
Hacker News API Part 5

ZIO is easy to use and very powerful, a great combination. Even though the applications are built using solid pure fp concepts such as the Reader and State monads, these are beneath the surface of the API, and the user can concentrate on building the application.
justinhj (@justinhj)


Scala Ordering Crash Course

In this video we are going to learn about Ordering - arguably the most known typeclass in Scala.
DevInsideYou (@DevInsideYou)


ScaLATAM, Montevideo, Uruuguay, May 2nd - 3rd

Don't miss the first Scala Conference in Latin America. Use promo code "scalatimes" to get 25% discount for our readers!
flatMap(Oslo), Oslo, Norway, May 8th - 9th

Use promo code SCALATIMES for a discount for our readers!
flatMap(Oslo) (@flatmaposlo)
Reactive Horizons, Orlando, Florida, May 31st

This conference is a unique opportunity to learn about top trending topics from today's Fast Data experts!
Reactive Horizons
CFP for LX Scala & Reactive, Lisbon, Portugal, July 4th - 5th

Don't miss the CFP deadline which is May 1st!
LX Scala & Reactive (@LX_Scala)
CFP for Lambda World, Cádiz, Spain, October 17th - 18th

Deadline for submissions is June 1st.
Lambda World (@lambda_world)
CFP for Scala Italy, Bologna, Italy, September 20th - 21st

Submit your proposal before May 5th.
Scala Italy (@ScalaItaly)
Scala in the City - Thursday 25th of April

Automatic differentiation in Scala by Xiayun Sun & Descriptions, APIs and Tapirs by Adam Warski
Scalainthecity (@Scalainthecity)


http4s 0.20.0-RC1

Headers is no longer an Iterable[Header], several changes related to 2.13 support, also some enhancements and bugfixes.
http4s contributors
Scala 2.13.0-RC1

Scala 2.13 is almost here! We are delighted to present the first 2.13 release candidate.
Scala contributors


Scala Times banners?

Want one? Click here
Scala Times stickers?

Want one? Let us know or tweet @scalatimes.

  1. Scala Times Issue #278

    Counting to infinity at compile time. Vectos - A functional ecosystem. Scala 2.13.0 for the Akka family. The place of applicative style in today's Scala. This Month We've Learned - May’19 .

  2. Scala Times Issue #277

    Final Free Structures with Subtyping. Exploring the STM functionality in ZIO. The Evolution of a Scala Programmer. How to work with Files in Scala. Top Link Of May: The little gems of Scala standard library.

  3. Scala Times Issue #276

    Small & fast Docker images using GraalVM’s native-image. SystemFw FP blog. IO monad: which, why and how. Counting at compile time. Why I'm Stepping Back from Scalaz.

  4. Scala Times Issue #275

    Tagless unions in scala 2.12. Combine IntelliJ IDEA with Hydra for the fastest Scala development experience. TMWL April’19  - qubits, scripting Google Apps & Scala tricks. Performant Functional Programming to the max with ZIO.

  5. Scala Times Issue #274

    AST playground: recursion schemes and recursive data. Rethinking Streaming Workloads with Akka Streams: Part I. Sharing is Caring!. A Scala tutorial for Java developers. Scala: Useful User Information + Why you should consider the Language.

  6. Scala Times Issue #273

    Community and Communication. Futures Made Easy with Scala. Scala: Useful User Information + Why you should consider the Language. Using 47 Degree's Fetch library with ZIO. Scala Compilation Got 5x Faster With Triplequote Hydra.

  7. Scala Times Issue #272

    The little gems of Scala standard library. Practical fiber safety (and how Concurrent implies Parallel). Typelevel Sustainability Program Announcement. Homegrown #Scala Collections - ScalaCheck / ScalaTest Integration. Alphabet Soup: Lensing, for free.

  8. Scala Times Issue #271

    ZIO & Cats Effect: A Match Made in Heaven. Concurrency is complicated. An introduction to Law Testing in Scala. Celebrating 10 Years of Akka. Alphabet Soup: Type-level transformations.

  9. Scala Times Issue #270

    Akka 2.6 roadmap. Extending MapR Database Queries Using Scala Polymorphic Types. Marvels of functional programming: Composing effects with monads. Traverse your HLists for fun and profit. Did Functional Programming get it wrong?.

  10. Scala Times Issue #269

    Scalar 2019 whiteboard voting. 38 lines of code towards better data validation in Scala. Scala: Internals and Intermediates. Hacker News API Part 5. Scala Ordering Crash Course.

  11. Scala Times Issue #268

    Functional Hangman with ZIO. Scala or Go: Tastes Great or Less Filling?. An Example of Free Monads and Optimization. Homegrown Scala Collections - Part 29 - Are Views Typeclasses?. Scalar, Warsaw, Poland April 5th - 6th.

  12. Scala Times Issue #267

    Bloop’s compiler performance is ~29% faster than SBT. Fourth batch of Scala 3 SIPs. Functional Hangman with ZIO. Scala: Understanding Variance. Fun with mutually-recursive typeclass resolution.

  13. Scala Times Issue #266

    The RedMonk Programming Language Rankings: January 2019. A monad is not a burrito. Joins in Apache Spark - Part 3. Scala sbt Project Directory Structure. Scala Snippets #1: Instantiable Implicits.

  14. Scala Times Issue #265

    Testing Incrementally with ZIO Environment. Finally Tagless - Not Quite Dead Yet. Functional Testing with Tagless-Final. Monad Transformers aren’t hard!. The Functional Scala Concurrency Challenge.

  15. Scala Times Issue #264

    Final Tagless seen alive. Effectful Episode with John de Goes. State vs Stateful Actor. Phil Bagwell Nominations. Introduction to Akka Streams.

  16. Scala Times Issue #263

    Describe, then interpret: HTTP endpoints using tapir. Vue.js with Playframework. Mu-RPC: defining messages and services. Validate Service Configuration in Scala. Modern Systems Programming And Scala Native With Richard Whaling.

  17. Scala Times Issue #262

    Is your Scala object always a singleton?. Freer doesn’t come for free. Maintaining Binary Compatibility in Scala. Anatomy of functors and category theory. A little Scala 'sed' class.

  18. Scala Times Issue #261: from Scala with love

    Aecor — Purely functional event sourcing in Scala. Part 5. Homegrown #Scala Collections - Foldable Maps. Kubernetes Liveness and Readiness Probes Revisited. Streams and Resource Safety | Akka. Assemble messages from Akka Actors.

  19. Scala Times Issue #260

    Cats Ecosystem Community Survey 2018 Results. Thread Pool Best Practices with ZIO. Purely functional parallelism in Scala. Finatra meets Ammonite. Typed Supervision: why the changes?.

  20. Scala Times Issue #259

    State of Scala compilation time in 2018. Low-memory symbol indexing with bloom filters. Finally: Top-level Definitions. Why you should think about functional programming. Toward a polyglot James server….

  21. Scala Times Issue #258

    Scala Days 2019 - Celebrating Collaborative Success. Scala community build grows, adds Scala 2.13 and JDK 11. Type-checked triple equals: Scala test. Using Scala Plugins From Gradle. Exploring Explicit Nulls in Dotty.

  22. Scala Times Issue #257

    High-Performance Functional Programming Through Effect Rotation. Trampolines for Everything. This month at SoftwareMill we’ve learned — December’18. A Guide to Scala Collections: Exploring Monads in Scala Collections. Spark Custom Stream Sources.

  23. Scala Times Issue #256

    Where is the llama for FS2?. Scala Best Practices - Foreword. Aecor - Purely functional event sourcing in Scala. Part 4b. Postgresql from Spark, how to query?. Error Handling in Akka Actor (with Future).

  24. Scala Times Issue #255

    ADT through the looking glass - lenses, prims and other optics. Hpc with scala and akka Actors. Scala Type Classes - The Name Printer. Evolutionary Algorithms on the JVM via Scala  -  a minimal introduction. Aecor - Purely functional event sourcing in Scala. Part 4a.

  25. Scala Times Issue #254

    Cats Ecosystem Community Survey 2018. Scala Developer Suvey Results 2018. Minutes of the 11th meeting of the Scala Center, Q4 2018. Software as a Reflection of Values With Bryan Cantrill. Dotty: An Alternative to Implicits.

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.