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January 31st, 2019, ISSUE 259


State of Scala compilation time in 2018

The data collected thanks to the survey indicate that in the best case the time lost because of compilation is around 25 to 30 minutes a day.
Mirco Dotta (@mircodotta)
Low-memory symbol indexing with bloom filters

Thanks to bloom filters, the three new indexes added in the last release of Metal use only a few megabytes of memory even for large projects with >500k lines of code.
Ólafur Páll Geirsson (@olafurpg)
Building a Big Data Machine Learning Spark Application for Flight Delay Prediction

In this tutorial, I explain how to develop a Spark application that allows creating a machine learning model for a real-world problem, using real-world data: Predicting the arrival delay of commercial flights.
Pedro Costa
Logging in Spark with Log4j. How to customize a driver and executors for YARN cluster mode

In this article, I’m going to describe several configurations for logging in Spark.
Oleksandr Tarasenko
Finally: Top-level Definitions

One of Scala 2’s small but persistently annoying warts is that many declarations can’t happen on their own.
Mark "Justin" Waks (@jducoeur)
Why you should think about functional programming

Writing code in a functional language gives you the opportunity to look at the issue from another aspect, where the development of your solution may be more effective.
Roman Taluyev
Toward a polyglot James server…

In our simple example, we replaced 127 lines of java code with 46 lines of Scala code.
Benoit Tellier (@TellierBenoit)
The Known Unknown: Working with Option and Nullable Types

There’s always a wild discussion between the followers of the two approaches about which concept is better, more concise or more functional and which not.
Benedikt Jerat (@benedikt_j42)
Reduce the domain of your types with Refined

Refined simply let us enforce our business rules into our types without all the boilerplate of defining classes and unsafe validations for each.
From Kentucky Mule to faster Scala compiler - project brief

An ambitious project aiming to create a completely new and blazing fast compiler.
Grzegorz Kossakowski (@gkossakowski)


Homegrown Scala Collections - Part 23 - Extracting Trees from Sets

In this video we will notice that our Sets are actually a mixture of Sets and Trees so we will invest some time into a heavy refactoring.
DevInsideYou (@DevInsideYou)


Scalar, Warsaw, Poland April 5-6, 2019

Join the next edition of the largest Scala conference in central Europe!
SoftwareMill (@softwaremill)
Lambda Days, Kraków, Poland, February 21-22, 2019

Use promo code SCALArlz10 for a 10% discount for our readers!
LambdaDays (@LambdaDays)
flatMap(Oslo), May 8-9, 2019

Use promo code SCALATIMES for a discount for our readers!
flatMap(Oslo) (@flatmaposlo)


Metals v0.4.0

Metals is a language server for Scala that works with VS Code, Atom, Vim, Sublime Text and Emacs.
Metals contributors
Slinky 0.5.2

Slinky is a framework for writing React apps in Scala with an experience just like using ES6.
Shadaj Laddad (@ShadajL)
clear-config 1.2.2

A type-safe, FP, Scala config library.
David Barri (@japgolly)
scalajs-react 1.4.0

React 16.6 & 16.7 support, VDOM modernisation and many other changes.
scalajs-react contributors


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