Haskell Weekly


Issue 374 2023-06-29

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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.


  • What’s the biggest development trend for 2023? (ad)

    Take the Developer Nation survey, share your opinion about tools and technologies and win cool prizes like an Apple MacBook Pro 13-Inch, Apple AirPods and dozens more! Start here!

  • Assumptions for Liquid Haskell in the large by Facundo Domínguez

    In this post we present a specific improvement that I integrated recently, which cuts down the maintenance cost to use LH when introducing assumptions about functions coming from large or multiple packages.

  • Bringing Fun into FP: Interview with Impure Pics by Denis Oleynikov

    In this article, we interview Jay, the mastermind behind Impure Pics. If you have been on Haskell Twitter for a while, you’ve definitely seen some of his drawings.

  • GHC activities report: April–May 2023 by Well-Typed

    This is the eighteenth edition of our GHC activities report, which describes the work on GHC and related projects that we are doing at Well-Typed.

  • Haskell: How a Lazy Language Was Put to Work (Part Three) by Obsidian Systems

    The history of Haskell dates back to the mid-eighties when there was a growing interest in lazy functional languages. At that time, a research committee was diligently working on designing a language suitable for teaching, research, and application development, as well as constructing large systems.

  • Haskell: Sourced Recursion Schemes by Leo Dillinger

    This is the third article in a series about recursion, focused on developing the birecursion-schemes library, although it is starting to grow beyond that scope.

  • ICFP Pearl preprint on rec-def by Joachim Breitner

    It is about the idea of using Haskell’s inherent ability to define recursive equations, and use them for more than just functions and lazy data structures.

  • LTS 21 release for ghc-9.4 and Nightly now on ghc-9.6 by Jens Petersen & Andreas Ländle

    The Stackage team is very happy to announce the first Stackage LTS version 21 snapshot has been released this week, based on GHC stable version 9.4.5.

  • Monadic lenses are the optic for right monad modules III by Jules Hedges

    If we’d like both our forwards and backwards passes to live in our monad then this is the simplest case that there is no possible concrete description, without using any quantification.

  • r/haskell will remain read-only by Taylor Fausak

    Until further notice, r/haskell will be read-only. You can still comment, but you cannot post.

  • Writing prettier Haskell with Unicode Syntax and Vim by Rodrigo Mesquita

    A short write-up on combining digraphs, a feature built-in to vim, and Haskell’s UnicodeSyntax extension, to easily write beautiful Haskell programs with unicode symbols.


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

In brief

Show & tell

  • base16 version 1.0 by Emily Pillmore

    This step in the library follows an RFC announced last year regarding a shift in the api for the base encoding libraries that would unlock several important optimizations and safety principles for them.

  • HLS version by Julian Ospald

    This is mainly a bindist release.

  • macaroni.nix by Armando Ramirez

    I’d like to properly announce the tooling I’ve been using to cross-compile my Haskell games 3 from Linux to Windows.

Call for participation