Haskell Weekly

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.

Survey

• 2022 State of Haskell Survey by Haskell Weekly

  This survey opens on November 1st and closes on the 15th. The goal of this survey is to better understand what people think of the Haskell programming language, together with its ecosystem and community. Whether you have never used Haskell or you use it every day, we want to hear from you!

Featured

• GHC 9.4.3 is now available by Ben Gamari

  The GHC developers are happy to announce the availability of GHC 9.4.3. This release is primarily a bugfix release addressing a few issues found in 9.4.2.

• GHC 9.2.5 released by Zubin Duggal

  The GHC developers are very happy to at announce the availability of GHC 9.2.5. This release is primarily a bugfix release addressing a few issues found in 9.2.4.

• Functional programming from sets and functions by Marco Perone

  In this post I would like to try a different approach, not requiring any programming knowledge, but only the most basic intuition.

• Improving the experience of JSON in Haskell with autodocodec and bifunctors by Dylan Martin

  Given the advantages laid out in that discussion, I decided to give that library a try on my project’s codebase, and it worked so well that, so I ended up refactoring basically all of my types to use autodocodec to generate JSON parsers for my types.

• A map of Haskell’s numeric types by Mark Dominus

  I keep getting lost in the maze of Haskell’s numeric types. Here’s lso the map I drew to help myself out.

• One recursion for all! Catamorphism step by step by Hackle Wayne

  One of the thrills of learning Haskell, is how something can come up out of the blue to completely invalidate my existing knowledge.

• Recompilation avoidance in rules_haskell by Guillaume Genestier

  In this blog post I explain how I improved recompilation avoidance in rules_haskell, a Bazel rule set to build Haskell code.

• Reinforcement learning for open games by Georgios Karachalias & Noon van der Silk

  In this post we illustrate how we built “Learning Games”, an integration between the open-games-hs framework and rllib, in order to gain access to the entire Python ecosystem and train agents for games written in Haskell.

• Security assessment by Trail of Bits, the new website and v4.2 released by Evgeny Poberezkin

  We have a growing number of enthusiasts using SimpleX Chat who can accept the security risks of unaudited system, but the users who depend on their security were patiently waiting until some independent experts validate our claims.

• Uniplate is a Traversal by Jack Kelly

  While writing code to rewrite some Dhall syntax trees, I noticed a cool connection between the core uniplate operation and optics.

Jobs

Trying to hire a Haskell developer? You should advertise with us!

In brief

• Haskell Foundation DevOps Weekly Update, 2022-11-09 by Bryan Richter

• Haskell Love 2021

• Haskell Talks as Mercury

• Let’s agree to be different. On empirical and deductive nature of coding. by Robert Peszek

  I have convinced myself that programmers tend to favor empirical or favor deductive. I call these camps pragmatists and theorists. This division impacts how we program and communicate.

• Zoom! Enhance! by Monday Morning Haskell

  Today we’ll be tackling the Day 20 problem from Advent of Code 2021. This problem is a fun take on the Zoom and Enhance cliche from TV dramas where cops and spies can always seem to get unrealistic details from grainy camera footage by “enhancing” it.

Show & tell

• haskell-benign by Arnaud Spiwack

  A library for benign effects in Haskell.

Call for participation

• Cabal: Display within which cabal.project we build
• unison: Bad handling of missing arrow in pattern matching