Haskell Weekly


Issue 400 2023-12-28

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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.


  • The new global Developer Nation survey is here! (ad)

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  • FRP in Yampa: Part 1 by Sandy Maguire

    I’ve been writing some Haskell lately, for the first time in a year, and it’s a total blast! In particular, school is out for the holidays, so I had some spare time, and thought I’d waste it by making a video game. In Haskell.

  • GHC activities report: October–November 2023 by Well-Typed

    This is the twenty-first edition of our GHC activities report, which describes the work on GHC and related projects that we are doing at Well-Typed. The current edition covers roughly the months of October and November 2023.

  • Serokell’s Work on GHC: Dependent Types, Part 2 by Serokell GHC team

    We have reached another milestone on our journey towards Dependent Haskell: Visible forall, part 2 has been implemented.

  • The Haskell Interlude Podcast by Joachim Breitner

    For most episodes we also have a transcript, so you can read the interviews instead, if you prefer, and you should find the podcast on most podcast apps as well. I do not know how reliable these statistics are, but supposedly we regularly have around 1300 listeners. We don’t get much feedback, however, so if you like the show, or dislike it, or have feedback, let us know (for example on the Haskell Discourse, which has a thread for each episode).


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

In brief

Show & tell

  • DevOps Weekly Log, 2023-12-20 by Bryan Richter

    In the last week, I finished migrating all the Stackage services to a new environment, so we’re nearly ready to do a cutover. I had to patch some of the software in order to make it happen, which is why I love DevOps: got a problem somewhere in the stack? Doesn’t matter where! You can fix it!

  • Parsing Mermaid Diagrams in Haskell by Rodrigo Mequita

    I wrote a parser for a small part of the mermaid diagram language. This came up while working in a project that uses mermaid to flesh out a design for some process. Since the devs would already write down mermaid specifications for visualising the diagram of these processes, I figured it would be useful if I could leverage the existing specification programatically, in Haskell.

  • Request for comment: functor-monad package by Koji Miyazato

    I’d like to introduce a category-theory-inspired library I’m making, and I want some feedbacks on it.

Call for participation

  • Technical Working Group: Call for Volunteers by José Manuel Calderón Trilla

    We presently have three openings on the working group, and we’re seeking volunteers. Members are expected to attend a monthly meeting, to participate in and moderate discussion threads regarding specific proposals, and to evaluate proposals for their technical merits. From time to time, committee members may also be asked to help a community member revise their proposal. The ability to communicate well and respectfully is important for any potential member.

  • unison: Make unique types the default