Haskell Weekly


Issue 291 2021-11-25

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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.


  • Haskell series part 7 by Pierre Guillemot

    This is the seventh article of a series on the functional language Haskell for beginners. In this article we are covering map, filter, foldl and function composition.

  • Announcing autodocodec by Tom Sydney Kerckhove

    Autodocodec is short for “Auto-documenting-codec”, or “self(auto)- documenting encoders and decoders”. Writing a Codec from autodocodec lets you encode and decode values, and document the parser all with a single value.

  • Automatically Migrating Eq of No (/=) by Sandy Maguire

    But that made me think — why do humans need to do this by hand? Computers are good at this sort of thing. So I wrote a tiny little comby config that does the replacements we want.

  • Happy and Alex MVP by Solomon Bothwell

    In my last post I gave a brief introduction to Happy and parser generators. In this post I will continue the story with Happy’s counterpart Alex.

  • Make invalid laziness unrepresentable by Tom Ellis

    Thunk leaks are a major cause of unpredictable memory usage in Haskell programs; a common cause of thunk leaks is lazy fields in data structures.

  • Parsing Permutations by Drew Olson

    I’m in a discord chat devoted mostly to the game and folks often share interesting bridge hands with one another. I decided it would be fun to build a program that parsed a simply-formatted bridge hand and produced a plain text bridge diagram.

  • Retrocomputing with Clash by Gergő Érdi

    Retrocomputing with Clash takes the experienced Haskell programmer on a journey into the world of hardware design with Clash. Our approach is based on using Haskell to its fullest potential, using abstractions like monads and lenses in building a library of reusable components.


  • Software Engineer at ACI Learning

    We are currently accepting applications for full-stack software professionals to join our small, but talented, multidisciplinary team.

  • Channable is looking for a Haskell team lead (ad)

    Channable is always hiring talented Haskell engineers and is now looking for someone to lead one of our Haskell teams. We’re a fast-growing international scale-up and while you can still benefit from the start-up vibe, working at Channable also means being part of a professional company with an outstanding development team.

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

In brief

  • AI Revisited: Breaking Down BFS by Monday Morning Haskell

    I figured I’d spend the last few weeks of the year with some AI related topics. This week, I’ll go over an algorithm that is really useful to understand when it comes to writing simple AI programs, and this is Breadth-First-Search.

  • Haskell Foundation Board meeting minutes 2021-11-18 by Théophile Choutri

    You can check out the minutes and agenda for the Board meeting that took place on the 2021-11-18.

  • Simon Peyton-Jones - A Microsoft Research Retrospective by Compositional

    With the news that Simon is leaving Microsoft Research, and now joining Epic Games, we’ve taken the opportunity to sit down and do a retrospective of his time at Microsoft Research and the various collaborations that have come about as part of that journey.

Show & tell

Call for participation