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February 21st, 2019, ISSUE 262


Is your Scala object always a singleton?

There's only one instance, right? Well, here's some bad news...
Jacek Kunicki (@rucek)
Freer doesn’t come for free

I don’t regret the detour I took to understand and use the Eff monad in anger to structure applications but I really don’t think that the benefits outweigh the costs.
Eric Torreborre (@etorreborre)
Maintaining Binary Compatibility in Scala

Keeping our dependencies up to date is an important goal, but every once in a while a presumably simple version update turns into a nerve-wrecking odyssey.
Ralf Gueldemeister (@rgueldem)
Anatomy of functors and category theory

In this article, I’ll try to give you an intuition about what is a functor and what do they look like in Scala.
Martin Menestret (@mmenestret)
A little Scala 'sed' class

A few times during the past year I got tired of trying to remember the Unix/Linux sed syntax while needing to make edits to many files, so this weekend I wrote a little sed-like Scala class.
Alvin Alexander (@alvinalexander)
Don't Use Await.result!

Almost regularly I see Scala code where people program in a sequential, synchronous style and integrate an asynchronous I/O call by waiting for its completion with Await.result. But you really shouldn’t.
Lutz Hühnken (@lutzhuehnken)
Aecor - Purely functional event sourcing in Scala. Part 6

I hope this post demonstrated how much Aecor wins from using final tagless. It’s also a great reminder of how much power this pattern gives.
Vladimir Pavkin (@vlpavkin)


Homegrown Scala Collections - Part 26 - Typical Operations on Maps

In this video we will implement the typical operations on Maps like withDefault or getOrElseUpdated and also see how Sets interact with Maps via operations like groupBy.
DevInsideYou (@DevInsideYou)


ScalaUA, Kiev, Ukraine, March 29-30

Use promo code ScalaTMS%_ScAlAUA-2019-29-30 for 20% discount for our readers!
ScalaUA (@ScalaUA_Conf)
Scalar, Warsaw, Poland April 5-6

Join the next edition of the largest Scala conference in central Europe!
SoftwareMill (@softwaremill)
flatMap(Oslo), May 8-9

Use promo code SCALATIMES for a discount for our readers!
flatMap(Oslo) (@flatmaposlo)
CFP for Lambda World, Cádiz, Spain, October 17th - 18th

Deadline for submissions is June 1st.
Lambda World (@lambda_world)
A Year of Scala in the City

What can we expect for the first birthday of the meetup?
Scalainthecity (@Scalainthecity)
BeeScala, 21-23 November, Ljubljana

Answer the question: "What is the idea behind the BeeScala name?", send your reply to info@bee-scala.org by 31st of March. For some lucky person, there's one free ticket waiting!
Bee Scala (@BeeScalaConf)


Quill 3.0

Free/Libre Compile-time Language Integrated Queries for Scala. 3.0 adds Monix streaming integration (for JDBC modules), a new dynamic query API, and Spark+Scala 2.12 support and a bunch of other new features.
Quill contributors


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