Issue 154 2019-04-11

Welcome to another issue of Haskell Weekly! Haskell is a safe, purely functional programming language with a fast, concurrent runtime. This is a weekly summary of what’s going on in its community.

Featured

Become a Better Haskeller by Learning About Inductive Types by Marko Dimjašević

While we usually and easily see the benefits of having a static type system on simple types such as integers, we might fail to see the benefits of applying the same principles to user-defined data types.
The Rubik’s Cube Group by Jared Corduan

Permutations and symmetry are central themes of group theory, so it is perhaps not surprising that the Rubik’s Cube has a nice algebraic description.
A Type of Programming by Renzo Carbonara

Computers blindly follow orders, and at some fundamental level, programming is about giving computers orders to follow.
Announcing Polysemy by Sandy Maguire

I want to announce my new library polysemy — it’s higher-order, no-boilerplate, zero-cost free monads.
Applicative Regular Expressions using the Free Alternative by Justin Le

Today, we’re going to implement applicative regular expressions and parsers (in the style of the regex-applicative library) using free structures!
Data Science in Haskell: An example using temperature data from Thailand and Myanmar by Dominic Steinitz

I have just returned from a cycling trip from Bangkok to Yangon. It was pretty hot.
Finding Property Tests by Hillel Wayne

This was a pretty short dive into what makes a good property or contract. It also focused on just pure functions.
GHC 8.8 Status by Ben Gamari

Needless to say, bringing this migration to a close ultimately required that we compromise on the 8.8.1 release schedule.
ghcid for Web App Development by Dennis Gosnell

One of the downsides of developing web applications in Haskell is the long recompilation cycle.

Jobs

Galois is Hiring! (ad)

Galois is looking for Software Engineers/Researchers and Project Managers! We collaborate with organizations like NASA, DARPA, and Amazon Web Services to explore blue sky ideas and turn them into usable technology. Some of the things we’ve worked on in the past: Formal methods, static analysis, binary analysis, cryptographic algorithms, domain specific languages, programming languages theory, abstract interpretation, type theory, formal verification and software correctness, reinforcement learning, autonomous systems assurance, communication security, cyber-deception for network defense, DDoS defense, provable hardware security, statistical anomaly detection for detecting advanced persistent threats. We think working here is awesome (see https://lifeatgalois.com).
Haskell programmers at Co-Star in New York

In brief

Package of the week

This week’s package of the week is gitlab-haskell, a library that queries and updates the database of a GitLab instance using the GitLab web API.

Call for participation

Events

North America

2019-04-11 in Raleigh, NC, USA by Raleigh Haskell Meetup: (hack . yack)
2019-04-12 in Austin, TX, USA by Austin Types, Theorems, and Programming Languages: Going through Software Foundations by Benjamin Pierce et al
2019-04-13 in California, CA, USA by California Peaks North: Haskell Peak Snowshoeing via Yuba Pass SnoPark
2019-04-13 in Norcross, GA, USA by Atlambda Haskathon: Atlambda Haskathon
2019-04-13 in Boston, MA, USA by Weekly Functional Programming Meetup: Hang out + short talk (topic not yet announced)
2019-04-15 in Irvine, CA by Orange Combinator - Functional Programming In OC: Combinating - The Weekly Function
2019-04-15 in Provo, UT, USA by Utah Haskell: Utah Haskell Meetup | Book Club
2019-04-16 in Minneapolis, USA by HaskellMN: HaskellMN Monthly Meetup
2019-04-16 in Santa Monica, CA, USA by Santa Monica Haskell Users Group: Dmitry Vagner: Neural Networks, Types, and Functional Programming
2019-04-17 in Austin, TX, USA by Austin Haskell Users Group: Haskell Beginner-Friendly Lab
2019-04-17 in St. Louis, MO, USA by Haskell Users Group: St. Louis: Build a Better Blog with Hakyll
2019-04-17 in Houston, TX, USA by Houston Functional Programmers: Testing and debugging soft real-time systems
2019-04-17 in Boulder, USA by Boulder Haskell Programmers: The Monoiad
2019-04-17 in Montréal, QC, Canada by Lambda Montreal: Sandy Maguire - Chasing the performance of Free Monads
2019-04-18 in Las Vegas, NV, USA by Las Vegas Functional Programming User Group: Functional Programming Meetup

Europe

2019-04-11 in London, United Kingdom by Hoodlums: Hoodlums Meetup
2019-04-15 in Karlsruhe, Germany by Karlsruhe Haskell Meetup: Parallel and Concurrent Programming Study Group
2019-04-15 in Delft, Netherlands by Delft Haskell Study Group: Haskell Study Session #8
2019-04-16 in Brighton, United Kingdom by Functional Brighton: Double whammy: The web as a monad and C# can be functional too!
2019-04-16 in London EC2, United Kingdom by Skills Matter - X Matters Keynote Series - Developer Events: Keynote by Liz Keogh: Decision Making for Grown-Ups
2019-04-17 in Berlin, Germany by Berlin Haskell Users Group: Haskell Wednesday
2019-04-17 in Brno-střed, Czech Republic by Functional Programming Brno: Haskell in Practice & Encode your Semantics in Types
2019-04-17 in London, United Kingdom by Skills Matter - X Matters Keynote Series - Developer Events: Keynote by Jessica Deen: From Zero to DevOps Superhero: The Container Edition
2019-05-24 in Kazan, Russia by FPure: FPure - functional programming conference

Asia

2019-04-11 in Taipei, Taiwan by Functional Thursday: Functional Thursday #72 （遇連假，順延一週）
2019-04-12 in Noida, India by Reactive Application Programmers in Delhi NCR: MEET-UP | Fearless Concurrency in RUST
2019-04-13 in Bengaluru, India by Bangalore Functional Programmers Meetup: Working with Postgres in Haskell

Oceania

2019-04-15 in Perth, Australia by Perth Functional Programmers: Haskell meetup (property-based testing with QuickCheck)
2019-04-16 in Auckland, New Zealand by Functional Programming Auckland: Learn Haskell Hands-on

South America

2019-04-16 in São Paulo, Brazil by HaskellBR - São Paulo: 9º Encontro de Haskellers de São Paulo @WeWork