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June 10th, 2021, ISSUE 382

READING

Cats: Essential Type Class Hierarchy, Explained

A walk through Semigroups, Monoids, Functors, Monads, and beyond.
Daniel Ciocîrlan (@rockthejvm)
Debugging and Observing Your Scala Code

A thorough analysis of the subject of context aware diagnostic logging.
Will Sargent (@will_sargent)
Programs as Values, Part III: Explicit Control Flow

In this post we see that using datatypes to describe effects requires modelling execution with explicit combinators, and that we can readily emulate sequential flow with this approach.
Fabio Labella
Programming in Scala Fifth Edition

PrePrint PDF update of Programming in Scala is now available. Use code SCALATIMESJUNEPINS5 for 15% off for our readers!
Martin Odersky, Lex Spoon, Bill Venners, and Frank Sommers (@ArtimaInc)

VIDEOS

Favor composition over inheritance in Scala3 with exports!

In this video we are going to see how some boilerplate associated with composition can be reduced in Scala3.
DevInsideYou (@DevInsideYou)
Migrating a functional app to Cats Effect 3

Cats Effect 3 is here and many libraries have released compatible versions - this means some applications can migrate to the new version of the Typelevel stack. In this video, I'm showing how I migrated one of my open source projects.
Jakub Kozłowski (@kubukoz)
Http4s Scala Tutorial: Writing an HTTP Server with Purely Functional Scala

In this video, we'll create a step-by-step REST application describing a movies database (a toy IMDB) and we'll showcase crucial aspects of the Http4s library.
Daniel Ciocîrlan (@rockthejvm)

EVENTS

Scala 3 for Scala 2 Developers (SF - Bay Area Edition), Jun 21st - 25th

In this course, developers who are already familiar with Scala 2.x will get a high-speed introduction to all the changes coming in Scala 3, including semantic changes, syntactic changes, new features, and dropped features. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
Functional Effects with ZIO 2.0 (SF Bay Area Edition), Jul 26th - Jul 30th

In this course, Scala developers will learn how to solve complex problems in asynchronous, concurrent programming using the ZIO library. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
Advanced ZIO (SF - Bay Area Edition), Aug 30th - Sep 3rd

In this course, developers will explore the edges and corners of the ZIO library, taking a close look at the fine-grained interruption, custom concurrency structures, streams, application configuring and tuning, and metrics and monitoring. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
Functional Design (SF - Bay Area Edition), Sep 27th - Oct 1st

In this course, developers will learn how to write simple functional solutions to everyday business problems, without jargon and without type classes. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
Functional Scala Fundamentals (SF - Bay Area Edition), Oct 17th - 22nd

In this course, developers will learn the foundations of functional Scala, including language features that are unique to functional Scala, core concepts in functional programming, and proven techniques for developing robust and powerful applications in functional Scala. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
ScalaCon, November 2nd - 5th

ScalaCon is a collaborative project brought to you by the folks behind Scala eXchange and Scala Days! Join us for two conferences packed with over 43 talks, networking opportunities, virtual sponsor booths, and a safe space for talking about our favorite language, its past , present, and future.
ScalaCon (@scalacon)
Build Web Servers with ZIO (SF - Bay Area Edition), Nov 15th - 19th

In this course, developers will use ZIO and best-in-breed libraries to rapidly construct web applications that are scalable; easy to test, refactor, and maintain; and which never leak resources or deadlock. Use our link to get a 20% discount for Scala Times readers!
John A. De Goes (@jdegoes)
Functional Scala, Dec 2nd - 3rd

Functional Scala 2021 returns for another year of great talks, familiar and fresh spaces, and positive energy around the power of functional Scala for delivering compelling solutions to the toughest technology problems. Use promo code SCALATIMES10 for a discount for our readers!
Functional Scala (@FunScala2021)

RELEASES

Scala 3.0.1-RC1

Further stabilising the compiler.
Scala contributors
code-examples-manager

Software tool to manage your notes and code examples, to publish them as gists or snippets.
David Crosson (@crodav)
delegate-macro

Annotation to automatically delegate/proxy implementation of interface to dependency.
Carlos Teixeira





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