#haskell ghcid supports cabal scripts now (3 years after I filed the feature request! :-)) 🎉

I'm sorry but writing mega-imperative Nintendo emulator code in #haskell is in fact both hilarious and weirdly enjoyable.

(I have no plans to stream this one, although I might make a video talking about it when I'm further along.)

GHC 9.12.4-rc1 is now available The GHC developers are very pleased to announce the availability of the release candidate for GHC 9.12.4. Binary distributions, source distributions, and documentation are available at downloads.has...

GHC 9.12.4-rc1 is available for testing! Please try it out on your projects and give feedback! It is available today on the GHCup pre-release channel. See the installation instructions: discourse.haskell.org/t/ghc-9-12-4...

#Haskell

New video: Drifting on the Seas of IO

Thumbnail painting: The Raft of the Medusa (1819) by Théodore Géricault.

This week we do a brief refresher on the IO Monad and "do" notation in #haskell

https://youtu.be/5McozSwG8uU

Drifting on the Seas of IO (Haskell Mooc, Set 11a) YouTube video by Tea Leaves

New video: Drifting on the Seas of IO

Thumbnail painting: The Raft of the Medusa (1819) by Théodore Géricault.

This week we do a brief refresher on the IO Monad and "do" notation in #haskell

youtu.be/5McozSwG8uU

This is amazing 😍

Solving `Passport Application` with Haskell
https://jameshaydon.github.io/passport/

#UK #Haskell #Citizenship

Fragment from a 6502 CPU emulator.

It turns out #Haskell is the world's best imperative language.

Blague à part, hormis en #haskell, où j'ai cette erreur affreuse du Skolem qui essaye de quitter son scope (ce qui semble absolument illégal), j'ai jamais trop compris ce que c’était si ce n'est qu'il n'est pas forcement possible d'inverser les "pour tout" et les "il existe".

A screenshot of the gchup TUI. My current version of ghc is 8.10.7 while the latest version is 9.14.1

My #haskell GHC is sooooo out of date, all my llvm-related stuff I wrote 2 years ago no longer works. Sigh.

Readings shared March 9, 2026 The readings shared in Bluesky on 9 March 2026 are: Fantastic simprocs and how to write them. ~ Yaël Dillies, Paul Lezeau. #LeanProver #ITP Formalization in Lean of faithfully flat descent of project

Readings shared March 09, 2026. jaalonso.github.io/vestigium/po... #AI #AI4Math #CategoryTheory #CoqProver #Emacs #FunctionalProgramming #Haskell #ITP #IsabelleHOL #LambdaCalculus #LeanProver #Lisp #Math #Physics #RocqProver

The floor is magma. ~ Alexandre Esteves. github.com/alexfmpe/sem... #Haskell #FunctionalProgramming

This is #Haskell and #Coq/#Rocq, not lean.

Category Theory for Programming In these lecture notes, we give a brief introduction to some elements of category theory. The choice of topics is guided by applications to functional programming. Firstly, we study initial algebras, ...

Category theory for programming. ~ Benedikt Ahrens, Kobe Wullaert. arxiv.org/abs/2209.012... #CategoryTheory #Haskell #LeanProver #FunctionalProgramming

Readings shared March 4, 2026 The readings shared in Bluesky on 4 March 2026 are: When AI writes the world’s software, who verifies it? ~ Leonardo de Moura. #AI #LeanProver #ITP Formalising sphere packing in Lean. ~ Chris Birkbec

Readings shared March 04, 2026. jaalonso.github.io/vestigium/po... #AI #AI4Math #CoqProver #FunctionalProgramming #Haskell #ITP #LeanProver #Math #RocqProver

Monuses and heaps. ~ Donnacha Oisín Kidney. doisinkidney.com/posts/2026-0... #Haskell #FunctionalProgramming

Layoutz 0.3.2 🪶 Zero-dep Elm-style TUI’s for Haskell - now w/ terminal plots & more Hello! Layoutz has quite some improvements including built-in granite-esque plots. Thanks for your great feedback thus far … sure you will find some more rough edges.

Layoutz! Zero-dep Elm-style TUI’s for #Haskell - now w/ terminal plots & more

discourse.haskell.org/t/layoutz-0-...

Pro #haskell tip.

In the repl, when you start a command (such as `sydTest spec`) which is actually behind the scene a "main" function which parses command line argument, you can pass any command line argument for free after your main function, e.g. `sydTest spec --golden-rest filteringArgument1`

Branch weight support by iand675 · Pull Request #744 · ghc-proposals/ghc-proposals Rendered

Notorious mad lad @iankduncan.com has opened a GHC Proposal to add hints to guide branch prediction! github.com/ghc-proposal...

This may be key to better register allocation and code layout.

#Haskell

I'm unappy about #haskell idea that different type must have the same name because they are in a different module, such as Vector.

It gives super nice (sarcasm) "hover" type signature in LSP, such as `convert :: Vector -> Vector`.

`text` and `bytestring` tried to fix that with `StrictXXX` aliases.

State of Haskell 2025 results At the end of 2025, the Haskell Foundation re-started the Haskell Yearly Survey. I’d like to thank Taylor Fausak for being supportive of our effort in conducting these surveys. The last survey was con...

It's there folks! The results of the State of #Haskell 2025 survey have been published

discourse.haskell.org/t/state-of-h...

A collage of several examples of 2D Graphics programming, including a version of the 2048 game, a chess board, pacman, snake, tetris and a tic-tac-toe

Brillo 2.0 - Production ready 2D graphics

#Haskell #Graphics

discourse.haskell.org/t/brillo-2-0...

Brillo 2.0 - Production ready 2D graphics I’m incredibly excited to announce Brillo 2.0! 🎉 This is a massive release and the result of our efforts to fix all the issues that make Haskell desktop apps feel like second-class citizens: Make anti-aliasing the default for all primitives Add support for true type fonts Add window refresh callback for live resizing support on macOS Add cursor shape support (pointer, crosshair, …) File system support: Add dialog to pick files or directories Support opening a save file dialog Add supp...

Brillo 2.0 - Production ready 2D graphics
discourse.haskell.org/t/brillo-2-0-production-...

> Brillo hides the pain of drawing simple vector graphics and raster images behind a nice data type and a few display functions.

#Haskell #Graphics

New video: "Great Programmers Are Lazy". An exploration of Haskell's principle of laziness, in the context of Set 10 of the #Haskell MOOC.

Thumbnail painting: Hubert Robert, "A Fishing Party" (1805).

https://youtu.be/alcv2Eu1wJk

Great Programmers Are Lazy YouTube video by Tea Leaves

New video: "Great Programmers Are Lazy". An exploration of Haskell's principle of laziness, in the context of Set 10 of the #Haskell MOOC.

Thumbnail painting: Hubert Robert, "A Fishing Party" (1805).

youtu.be/alcv2Eu1wJk

What The Functor? YouTube video by Tea Leaves

#Haskell livestream: What the Functor?

youtube.com/live/7RasneK...

Readings shared February 24, 2026 The readings shared in Bluesky on 24 February 2026 are: Formalizing Gröbner basis theory in Lean. ~ Junyu Guo, Hao Shen, Junqi Liu, Lihong Zhi. #LeanProver #ITP #Math Integral curves and flows on Ban

Readings shared February 24, 2026. jaalonso.github.io/vestigium/po... #AI4Math #ATP #Agda #CoqProver #FunctionalProgramming #Haskell #ITP #IsabelleHOL #LLMs #LeanProver #Math #Reasoning #Vampire

Haskell meets Evariste Since its birth as a new scientific body of knowledge in the late 1950s, computer programming has become a fundamental skill needed in many other disciplines. However, programming is not easy, it is p...

Haskell meets Evariste. ~ Paulo R. Pereira, Jose N. Oliveira. arxiv.org/abs/2602.168... #Haskell #FunctionalProgramming

Exported for tests only: Precise control over API visibility with custom warnings This article describes a pattern made possible by recent advances in GHC 9.8, to allow library authors to control how internal data constructors can be labelled as unsafe for human consumption, while ...

Exported for tests only: Precise control over API visibility with custom warnings

#Haskell

tech.scrive.com/exported-for...

New Haskell Debugger Release: v0.12 I’m happy to announce a new release of the new modern step-through interactive debugger (haskell-debugger). You can find installation instructions in GHC Debugger. Here’s the changelog for haskell-de...

New #Haskell Debugger Release: v0.12

discourse.haskell.org/t/new-haskel...

[ANN] sabela - A reactive Notebook for Haskell Sabela is a reactive notebook environment for Haskell. The name is derived from the Ndebele word meaning “to respond.” The project has two purposes. Firstly, it is an attempt to design and create a mo...

Sabela - A reactive Notebook for #Haskell by the DataHaskell project

Announcement: discourse.haskell.org/t/ann-sabela...

Github Repository: github.com/DataHaskell/...