Haskell Weekly


Issue 301 2022-02-03

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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.


  • GSoC 2022 Ideas

    This is a list of ideas for contributors who are considering to apply to Google Summer of Code 2022 for Haskell.org.

  • Introduction to Free Monads by Nikolay Yakimov

    If you’ve been around Haskell circles for a bit, you’ve probably seen the term “free monads”. This article aims to introduce free monads and explain why they are useful.

  • A plain English description of monads without Haskell code by Chris Done

    I’ve been using Haskell for over a decade and have refrained from writing yet another monad tutorial. A friend asked for an easy explanation of them that doesn’t involve Haskell code. That’s easier.

  • Showcase: deriving-trans by Felix Springer

    When creating monad transformer stacks, you usually have to implement some instances manually. Here is a way how this can mostly be avoided.

  • Software Development Languages: Haskell by Colin Woodbury

    Haskell is an active language used all over the world by normal developers. Code is clean and fast, there are libraries for anything you’d want to do, its concurrency idioms are nearly best-in-class, and maintenance/refactors are much cheaper than some other languages.

  • Underlining the Bugs by Sandy Maguire

    I had a magical Haskell experience today, and want to share the story.


  • Haskell Developer at MLabs (ad)

    We are one of the leading Haskell consultancies in the fintech, blockchain and AI space, with a passion for Haskell and open source software. We are looking for a remote Haskeller to join our team. If you are excited about Haskell and are up for a new challenge, please apply here or visit our website! For any questions please email jobs@mlabs.city.

  • Haskell Software Engineer at Bitnomial (Chicago,IL,US Remote) (ad)

    Bitnomial is looking for Haskell Software Engineers. Bitnomial is a US based, CFTC licensed and regulated bitcoin derivatives exchange, headquartered in Chicago. Bitnomial develops and operates exchange, clearing, and settlement infrastructure for physically settled bitcoin futures and options.

  • Backend Developer at Holmusk (ad)

    Holmusk is using Haskell to build digital health products. We are looking for remote Haskellers to join our team across Europe for now, but also in the US soon. Are you excited about using Haskell to improve the mental health of millions of people? Do you want to work alongside smart and mission-driven people across 20 countries? Please apply here or visit our website! As a Haskell Developer, you will be working within the Holmusk Product Team so you might be interested to read up on this blog too: https://holmusk.dev. For any questions please email me at adam.cooke@holmusk.com.

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

In brief

  • GHC Steering Committee Call for Nominations by Joachim Breitner

    The GHC Steering committee is seeking nominations for at least two new members.

  • Haskell Beginners 2022: Free online Haskell course by Dmitrii Kovanikov

    In January 2022 I was teaching a free Haskell course for complete beginners. No prior knowledge of Haskell was required.

  • Monthly Hask Anything (February 2022)

    This is your opportunity to ask any questions you feel don’t deserve their own threads, no matter how small or simple they might be!

  • Simple property-based tests for Plutus validators by Victor Cacciari Miraldo

    How to write off-chain code with the ‘cooked-validators’ library and get property-based tests for free.

  • To Infinity and Beyond! by Monday Morning Haskell

    For this last set of functions, we’ll explore some items that are very helpful when you are using infinite lists in Haskell.

  • Why I am Learning Haskell by Chester Beard

    Okay, okay I know that Cardano has for years now been more hype than an actual project. It has just developed smart contract systems development, so it is only recently that you could develop any working programs for the ecosystem.

Show & tell

  • cleff

    I’m pleased to announce cleff, a new extensible effects library for Haskell.

  • Haskell Language Server version

  • High-order Virtual Machine (HVM) by Victor Taelin

    High-order Virtual Machine (HVM) is a pure functional compile target that is lazy, non-garbage-collected and massively parallel. It is also beta-optimal, meaning that, in several cases, it can be exponentially faster than most functional runtimes, including Haskell’s GHC.

  • Rel8 version 1.3 by Ollie Charles

    Rel8 is a Haskell library for interacting with PostgreSQL databases, built on top of the fantastic Opaleye library.

  • Servant version 0.19 by Gaël Deest

Call for participation