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January 14th, 2021, ISSUE 361


Scala 3: Dependent Types, Part II

In this post, I’ll visit some more sophisticated capabilities provided by dependent typing.
Dean Wampler (@deanwampler)
Configuring and suppressing warnings in Scala

Scala 2.13.2 introduced the -Wconf compiler flag to globally configure reporting of warnings, and the @nowarn annotation to locally suppress them.
Lukas Rytz (@lrytz)
sttp client 3 is here!

Learn about all the new features and improvements of sttp.
Adam Warski (@adamwarski)
Kittens High on Catnip - Squeaky Clean Type Class Derivation in Scala

In this post, we will start by examining how you can use auto derivation for faster and more efficient prototyping. Then, we’ll discuss the caveats when moving to production code, and how you can avoid them. I will close by showing how you can make your auto-deriving production code even tidier and cleaner.
Kiril Yurovnik
Threading best practices in Cats Effect

I regularly get asked what the best way to manage threadpools in Cats Effect is and what ContextShift does so this is my attempt to write a consistent explanation that I can point to. My intention is to cover both Cats Effect 2 and Cats Effect 3, although at the time of writing the latter is at milestone 5 so some details are subject to change.
Tim Spence


Scala 3 Metaprogramming by Example by Adam Warski

Metaprogramming is one of the features that sets Scala 3 apart from other languages. We don’t only get “macros done right”, but a couple of constructs that can be used depending on the scope and complexity of the task: inlines, type class derivation, and “proper” macros (quoting & splicing).
Adam Warski (@adamwarski)
What the Functor?

In this video we'll explore functors, a critical piece of abstract functional programming. Rather than explaining the theory behind it, we go through a concrete use-case of generalizing an API that would otherwise be terribly bloated and repeated.
Daniel Ciocîrlan (@rockthejvm)
Parallel analysis of temperature dataset

In this video, we'll start the analysis of a real-world dataset of average temperatures by city. Our goal is to design an API that processes data in parallel so that we can leverage modern computer architecture with multiple CPUs.
Julien Truffaut (@TheFpTower)


Essential Effects, 27th-29th January, Online Event

This course introduces Cats Effect as a tool for building resource-safe and concurrent applications. (US timezone). Use code 'scalatimes' for a 15% discount!
Inner Product (@InnerProductLLC)
Lambda Days 2021, 16th - 19th February, Virtual Event

Don't forget to check the Diversity Scheme - we have a pool of tickets to be distributed among participants from groups underrepresented in IT.
LambdaDays (@LambdaDays)
ZIO World, 1th March, Online Event

Join ZIO users and contributors for the inaugural ZIO World, which reveals ZIO 2.0, providing inspiration and new opportunities to create the most powerful reactive applications on the JVM. FREE of charge for all ZIO Contributors and Users.
Ziverge (@zivergetech)


Scala 2.12.13

Adds support for configurable warnings and errors (@nowarn and -Wconf), backported from 2.13, and more improvements.
Scala contributors

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