# Show and Tell **URL:** https://discourse.haskell.org/c/show-and-tell/7.md [Latest](https://discourse.haskell.org/latest.md) · [Categories](https://discourse.haskell.org/categories.md) · [Tags](https://discourse.haskell.org/tags.md) --- ## [About the Show and Tell category](https://discourse.haskell.org/t/about-the-show-and-tell-category/15)
**Author:** [@jaspervdj](https://discourse.haskell.org/u/jaspervdj)\ **Replies:** 0
If you made something using Haskell, you can show the community and tell us about it here. --- ## [Rust-style Attribute Macro in Haskell, using GHC 10 Modifiers Extension](https://discourse.haskell.org/t/rust-style-attribute-macro-in-haskell-using-ghc-10-modifiers-extension/14726)
**Author:** [@konn](https://discourse.haskell.org/u/konn)\ **Replies:** 10\ **Last updated:** [September 26, 2026, 12:31pm UTC](https://discourse.haskell.org/t/rust-style-attribute-macro-in-haskell-using-ghc-10-modifiers-extension/14726 "2026-09-26T12:31:07Z")
As a long-time Haskeller writing Rust in production, I always miss the powerful Template Haskell macros - Rust’s macro system is rather ad-hoc and weaker than Haskell (it fails to handle hygienity properly, and, cruciall… --- ## [Lask — a task runner with its own typed language, written in Haskell](https://discourse.haskell.org/t/lask-a-task-runner-with-its-own-typed-language-written-in-haskell/14713)
**Author:** [@torudev](https://discourse.haskell.org/u/torudev)\ **Replies:** 0\ **Last updated:** [September 20, 2026, 10:05am UTC](https://discourse.haskell.org/t/lask-a-task-runner-with-its-own-typed-language-written-in-haskell/14713 "2026-09-20T10:05:06Z")
This is my first post here, and I’m afraid it’s about my own project — I hope that’s an acceptable way to introduce myself. What I made Lask is a task runner. It replaces Makefiles and CI YAML with a small typed languag… --- ## [First Draft: Little Haskell Compiler Adventures: The SECD Machine](https://discourse.haskell.org/t/first-draft-little-haskell-compiler-adventures-the-secd-machine/14560)
**Author:** [@ApothecaLabs](https://discourse.haskell.org/u/ApothecaLabs)\ **Replies:** 16\ **Last updated:** [September 15, 2026, 10:48pm UTC](https://discourse.haskell.org/t/first-draft-little-haskell-compiler-adventures-the-secd-machine/14560 "2026-09-15T22:48:41Z")
STATUS: This article is a little bit rough, but I’ve been working on it long enough that its worth publishing now, and editing to fix anything. I really should have published it earlier, because I actually broke the char… --- ## [Case-split plugin at GSoC 2026 - Retrospective](https://discourse.haskell.org/t/case-split-plugin-at-gsoc-2026-retrospective/14690)
**Author:** [@enlico](https://discourse.haskell.org/u/enlico)\ **Replies:** 1\ **Last updated:** [September 14, 2026, 12:23pm UTC](https://discourse.haskell.org/t/case-split-plugin-at-gsoc-2026-retrospective/14690 "2026-09-14T12:23:44Z")
Google Summer of Code was hands down the most exciting opportunity and, in hindsight, the most formative experience in my software development journey. Multiple factors contributed to me considering this adventure so hi… --- ## [Effectful is better at running unspecialized mtl-style code than transformers](https://discourse.haskell.org/t/effectful-is-better-at-running-unspecialized-mtl-style-code-than-transformers/14648)
**Author:** [@arybczak](https://discourse.haskell.org/u/arybczak)\ **Replies:** 3\ **Last updated:** [September 9, 2026, 7:15am UTC](https://discourse.haskell.org/t/effectful-is-better-at-running-unspecialized-mtl-style-code-than-transformers/14648 "2026-09-09T07:15:38Z")
This is something I’ve discovered a year ago and wanted to include in a refined version of benchmarks, but since I didn’t manage to do that in such a long time, let me just share this particular bit. A reminder: count… --- ## [Haskue: exploring CUE evaluation in Haskell](https://discourse.haskell.org/t/haskue-exploring-cue-evaluation-in-haskell/14643)
**Author:** [@jzhonx](https://discourse.haskell.org/u/jzhonx)\ **Replies:** 4\ **Last updated:** [September 5, 2026, 12:35pm UTC](https://discourse.haskell.org/t/haskue-exploring-cue-evaluation-in-haskell/14643 "2026-09-05T12:35:42Z")
Hi everyone, I would like to share a project I have been working on for a while: Haskue, an experimental Haskell implementation of part of the CUE configuration language. Try it online — it runs as WebAssembly, so no … --- ## [Welcome again the Case Split plugin for HLS](https://discourse.haskell.org/t/welcome-again-the-case-split-plugin-for-hls/14469)
**Author:** [@enlico](https://discourse.haskell.org/u/enlico)\ **Replies:** 9\ **Last updated:** [September 4, 2026, 8:38am UTC](https://discourse.haskell.org/t/welcome-again-the-case-split-plugin-for-hls/14469 "2026-09-04T08:38:09Z")
Welcome again the Case Split plugin for HLS Hello everybody! This summer I am a contributor to GSoC, and I’m pouring my energies and keystrokes into the HLS ecosystem, specifically into #5013, by bringing back to life a… --- ## [Experiments with Template Haskell, SQL, and Records](https://discourse.haskell.org/t/experiments-with-template-haskell-sql-and-records/14636)
**Author:** [@stevechy](https://discourse.haskell.org/u/stevechy)\ **Replies:** 9\ **Last updated:** [September 3, 2026, 2:04pm UTC](https://discourse.haskell.org/t/experiments-with-template-haskell-sql-and-records/14636 "2026-09-03T14:04:50Z")
Hello, I’ve been playing around with Template Haskell and Hasql and have posted the results on github. The idea is to generate code to make lining up db columns and record field names easier. It’s been a while since I… --- ## [Verifying Verifying Algorithm](https://discourse.haskell.org/t/verifying-verifying-algorithm/14626)
**Author:** [@dyaitskov](https://discourse.haskell.org/u/dyaitskov)\ **Replies:** 3\ **Last updated:** [August 29, 2026, 10:43am UTC](https://discourse.haskell.org/t/verifying-verifying-algorithm/14626 "2026-08-29T10:43:27Z")
Verifying Verifying Algorithm Impression about Lean4 I’ve been studying Lean for several weeks as a programming language and as a proof assistant, I would like to share my experience. My last Haskell project miso-css mo… --- ## [Space.hs by Telorum](https://discourse.haskell.org/t/space-hs-by-telorum/14615)
**Author:** [@Execute](https://discourse.haskell.org/u/Execute)\ **Replies:** 4\ **Last updated:** [August 27, 2026, 7:39am UTC](https://discourse.haskell.org/t/space-hs-by-telorum/14615 "2026-08-27T07:39:54Z")
https://telorum.itch.io/space-hs --- ## [RFC: haskell bindings to procps and higher-level library](https://discourse.haskell.org/t/rfc-haskell-bindings-to-procps-and-higher-level-library/14561)
**Author:** [@fpringle](https://discourse.haskell.org/u/fpringle)\ **Replies:** 2\ **Last updated:** [August 17, 2026, 8:30am UTC](https://discourse.haskell.org/t/rfc-haskell-bindings-to-procps-and-higher-level-library/14561 "2026-08-17T08:30:34Z")
I just stumbled across a project I was working on early last year. Evidently I must have got distracted by something else. Nevertheless, the project seems to be in decent shape with good documentation (missing a README b… --- ## [Ghc-vis-ds: a modern port of ghc-vis with a Datastar frontend](https://discourse.haskell.org/t/ghc-vis-ds-a-modern-port-of-ghc-vis-with-a-datastar-frontend/14520)
**Author:** [@carlo\_h](https://discourse.haskell.org/u/carlo_h)\ **Replies:** 0\ **Last updated:** [August 6, 2026, 1:56am UTC](https://discourse.haskell.org/t/ghc-vis-ds-a-modern-port-of-ghc-vis-with-a-datastar-frontend/14520 "2026-08-06T01:56:52Z")
Here’s my port of ghc-vis with a Datastar web frontend: Demo site with some pre-built examples: https://ghc-vis-ds.hamalainen.dev/ Screenshot: My hope is that this will be easy to run for beginners who want to le… --- ## [Designing a Hook in Haskell (Video)](https://discourse.haskell.org/t/designing-a-hook-in-haskell-video/14488)
**Author:** [@hungryjoe](https://discourse.haskell.org/u/hungryjoe)\ **Replies:** 0\ **Last updated:** [July 31, 2026, 9:14am UTC](https://discourse.haskell.org/t/designing-a-hook-in-haskell-video/14488 "2026-07-31T09:14:42Z")
In 2018, I designed a Parametric Hook in OpenSCAD, a Programmable CAD framework. Since then, I’ve built my own library for Programmable CAD, called Waterfall-CAD. In this video, I use Haskell and Waterfal… --- ## [Cabal-add: extend Cabal build-depends from the command line](https://discourse.haskell.org/t/cabal-add-extend-cabal-build-depends-from-the-command-line/7911)
**Author:** [@Bodigrim](https://discourse.haskell.org/u/Bodigrim)\ **Replies:** 36\ **Last updated:** [July 27, 2026, 7:28pm UTC](https://discourse.haskell.org/t/cabal-add-extend-cabal-build-depends-from-the-command-line/7911 "2026-07-27T19:28:09Z")
As discussed at Convenience in the Haskell ecosystem - #169 by Bodigrim, I’ve developed a small command-line tool to add build-depends. I tried a few examples and convinced myself that it’s robust enough, but would app… --- ## [Openleetcode – LeetCode runner where tests live in the repo](https://discourse.haskell.org/t/openleetcode-leetcode-runner-where-tests-live-in-the-repo/14409)
**Author:** [@therepanic](https://discourse.haskell.org/u/therepanic)\ **Replies:** 4\ **Last updated:** [July 19, 2026, 1:54pm UTC](https://discourse.haskell.org/t/openleetcode-leetcode-runner-where-tests-live-in-the-repo/14409 "2026-07-19T13:54:32Z")
You write a standard solution, just like on LeetCode, and run it through the CLI. It identifies the problem by ID or title, executes your code against local test cases, and shows the result. It currently supports around… --- ## [Espial bookmarking server](https://discourse.haskell.org/t/espial-bookmarking-server/14395)
**Author:** [@jonschoning](https://discourse.haskell.org/u/jonschoning)\ **Replies:** 7\ **Last updated:** [July 16, 2026, 1:44pm UTC](https://discourse.haskell.org/t/espial-bookmarking-server/14395 "2026-07-16T13:44:37Z")
I’d like to share my self-hosted bookmarking server written in Haskell & Typescript, backed by SQLite (in the spirit of Pinboard). Repo: https://github.com/jonschoning/espial Demo: https://espdemo.ae8.org/u:demo (user… --- ## [Haskell Active Automata Learning](https://discourse.haskell.org/t/haskell-active-automata-learning/14415)
**Author:** [@steve-anunknown](https://discourse.haskell.org/u/steve-anunknown)\ **Replies:** 0\ **Last updated:** [July 15, 2026, 9:59pm UTC](https://discourse.haskell.org/t/haskell-active-automata-learning/14415 "2026-07-15T21:59:30Z")
Hey all, I wanted to share with you a library I’ve been working on for the past year. The library is named haal (Haskell Active Automata Learning) and it is available on github and on hackage. The aim of the library is… --- ## [I've been working on a Haskell Powered CAD Playground](https://discourse.haskell.org/t/ive-been-working-on-a-haskell-powered-cad-playground/14362)
**Author:** [@hungryjoe](https://discourse.haskell.org/u/hungryjoe)\ **Replies:** 6\ **Last updated:** [July 10, 2026, 4:59am UTC](https://discourse.haskell.org/t/ive-been-working-on-a-haskell-powered-cad-playground/14362 "2026-07-10T04:59:55Z")
I’ve been working on a Haskell powered CAD playground. It run’s entirely in the browser, in Web Assembly; this is made possible thanks to the GHC WASM backend, by Cheng Shao et al. --- ## [BitNet 1.58 in MicroHaskell: Exploring minimal LLMs and combinators (Experience Report)](https://discourse.haskell.org/t/bitnet-1-58-in-microhaskell-exploring-minimal-llms-and-combinators-experience-report/14325)
**Author:** [@Tritlo](https://discourse.haskell.org/u/Tritlo)\ **Replies:** 4\ **Last updated:** [June 29, 2026, 6:31pm UTC](https://discourse.haskell.org/t/bitnet-1-58-in-microhaskell-exploring-minimal-llms-and-combinators-experience-report/14325 "2026-06-29T18:31:08Z")
Some background: I’ve recently become obsessed with combinators, specifically iota, where: i x = x S K It’s a single combinator basis that gives you i i = I, i I = A (A x y = y), i A = K, i K = S so you can recover S,… --- ## [Flexible Haskell - a new plugin for JetBrains IDEs](https://discourse.haskell.org/t/flexible-haskell-a-new-plugin-for-jetbrains-ides/13813)
**Author:** [@madppiper](https://discourse.haskell.org/u/madppiper)\ **Replies:** 68\ **Last updated:** [June 27, 2026, 4:54am UTC](https://discourse.haskell.org/t/flexible-haskell-a-new-plugin-for-jetbrains-ides/13813 "2026-06-27T04:54:30Z")
Hey everybody, glad to be in touch. I recently launched a Haskell language implemntation for all JetBrains IDEs (IntelliJ, PyCharm, CLion, GoLand, RubyMine etc) and am now looking for early adopters. It is called “Flex… --- ## [A Quick Tour of a (WIP) Pure Haskell Software Renderer](https://discourse.haskell.org/t/a-quick-tour-of-a-wip-pure-haskell-software-renderer/14301)
**Author:** [@tobz619](https://discourse.haskell.org/u/tobz619)\ **Replies:** 0\ **Last updated:** [June 21, 2026, 11:47am UTC](https://discourse.haskell.org/t/a-quick-tour-of-a-wip-pure-haskell-software-renderer/14301 "2026-06-21T11:47:27Z")
Link: https://youtu.be/ARbqQMe88Qo Apologies for the audio. I had already tried and failed to record this 4 times, and by this point I gave up. Next update will certainly have fixed audio. This is a pure Haskell CPU re… --- ## [Sabela Notebook Gallery](https://discourse.haskell.org/t/sabela-notebook-gallery/14271)
**Author:** [@mchav](https://discourse.haskell.org/u/mchav)\ **Replies:** 2\ **Last updated:** [June 14, 2026, 1:36pm UTC](https://discourse.haskell.org/t/sabela-notebook-gallery/14271 "2026-06-14T13:36:36Z")
Thanks to @tomjaguarpaw and @hungryjoe for contributing. If anyone has any tutorial or script that they’d like to showcase let me know. --- ## [Blog: Haskell for Elm developers, Part 8 — IO](https://discourse.haskell.org/t/blog-haskell-for-elm-developers-part-8-io/14267)
**Author:** [@kutyel](https://discourse.haskell.org/u/kutyel)\ **Replies:** 0\ **Last updated:** [June 12, 2026, 2:13pm UTC](https://discourse.haskell.org/t/blog-haskell-for-elm-developers-part-8-io/14267 "2026-06-12T14:13:23Z")
Latest in my series teaching Haskell via Elm concepts. This one explains IO through Task/Cmd: descriptions of effects, composed monadically, run only at the main boundary. Includes an honest look at where the analogy bre… --- ## [H2JVM - A Haskell Library for writing JVM Bytecode](https://discourse.haskell.org/t/h2jvm-a-haskell-library-for-writing-jvm-bytecode/14182)
**Author:** [@bristermitten](https://discourse.haskell.org/u/bristermitten)\ **Replies:** 19\ **Last updated:** [June 10, 2026, 5:10pm UTC](https://discourse.haskell.org/t/h2jvm-a-haskell-library-for-writing-jvm-bytecode/14182 "2026-06-10T17:10:49Z")
Hi everyone! I have been working on a new library for writing JVM bytecode with Haskell in a nice, high level way and I’d love some feedback on it! The motivation here is for compilers to the JVM so they can focus on th… --- ## [Extension or Imitation?](https://discourse.haskell.org/t/extension-or-imitation/14203)
**Author:** [@hungryjoe](https://discourse.haskell.org/u/hungryjoe)\ **Replies:** 2\ **Last updated:** [June 7, 2026, 11:58am UTC](https://discourse.haskell.org/t/extension-or-imitation/14203 "2026-06-07T11:58:25Z")
I wrote this little Haskell Quiz (with help from some friends); in the style of “CSS or BS”; Can you tell the valid Haskell Language Extensions (based on the GHC docs), from the Impostors? --- ## [Haskell Ant Simulator Talk](https://discourse.haskell.org/t/haskell-ant-simulator-talk/14140)
**Author:** [@OlegAlexander](https://discourse.haskell.org/u/OlegAlexander)\ **Replies:** 21\ **Last updated:** [May 23, 2026, 8:14pm UTC](https://discourse.haskell.org/t/haskell-ant-simulator-talk/14140 "2026-05-23T20:14:02Z")
Hello Haskell community, I’ve created an agent-based ant foraging simulator in Haskell. I also have a 40-minute talk about this project. I’ve already delivered the talk at my company, and it was well received. Now I … --- ## [Haskell Brain Teasers](https://discourse.haskell.org/t/haskell-brain-teasers/13833)
**Author:** [@rebeccaskinner](https://discourse.haskell.org/u/rebeccaskinner)\ **Replies:** 2\ **Last updated:** [May 19, 2026, 7:33am UTC](https://discourse.haskell.org/t/haskell-brain-teasers/13833 "2026-05-19T07:33:28Z")
Hi everyone! I wanted to share that the final version of my new book, Haskell Brain Teasers is now available. I’m really excited to share this with everyone. It’s a puzzle book. Every one of the puzzles is in the form … --- ## [KnownNat-indexed vectors](https://discourse.haskell.org/t/knownnat-indexed-vectors/14099)
**Author:** [@mixphix](https://discourse.haskell.org/u/mixphix)\ **Replies:** 23\ **Last updated:** [May 15, 2026, 5:39pm UTC](https://discourse.haskell.org/t/knownnat-indexed-vectors/14099 "2026-05-15T17:39:02Z")
The way sized vectors are usually implemented in Haskell is with a data declaration, typically involving several fields of the same type, for example: data V3 x = V3 !x !x !x deriving ({- ... -}) This representation ha… --- ## [Ghc now runs in your browser](https://discourse.haskell.org/t/ghc-now-runs-in-your-browser/13169)
**Author:** [@TerrorJack](https://discourse.haskell.org/u/TerrorJack)\ **Replies:** 30\ **Last updated:** [May 7, 2026, 4:34pm UTC](https://discourse.haskell.org/t/ghc-now-runs-in-your-browser/13169 "2026-05-07T16:34:11Z")
ghc itself can now run purely client-side in the browser, here’s a haskell playground demo. terms and conditions apply, and i’ll write up more detailed explanation some time later, but i thought this is a cool thing to… [Next page](https://discourse.haskell.org/c/show-and-tell/7.md?page=1)