Chris Penner

Chris Penner

@chrispenner.ca

FP and Programming languages nerd Building the Unison Language & Unison Share 📍Victoria BC 🇨🇦 https://chrispenner.ca

557 followers609 following263 posts

Chris Penner
@chrispenner.ca

Another @unison-lang.org feature I think every language should have in some capacity: Streams! Unison's effect system makes them even more useful since you can interleave effects into your streams. A Stream or Coroutine abstraction is so useful as a way for libraries to consume or provide data.

Chris Penner
@chrispenner.ca

Obviously many other languages have a take on this, but in Haskell for example there are many different and incompatible kinds. Optimizing for specific use-cases is nice, but I think having a shared foundational and compatible interface wins out in this case.

Chris Penner
@chrispenner.ca

In Unison it's great because producers use the Stream effect, and you can upgrade it to a Coroutine by just adding the `Ask` effect, they compose!

Chris Penner
@chrispenner.ca

No other language lets me write straight-line code like this. The `prompt` line saves saves the current continuation in a database, then sends a prompt to the user's browser to select a slot. When selected, `prompt` returns the in-memory @unison-lang.org object which corresponds to the chosen slot.

Chris Penner
@chrispenner.ca

It doesn't look like much, and that's kinda the point. That single line saves the full workflow seamlessly to a DB, it can be re-hydrated and continue running like nothing happened whenever the response is received whether in a second or a week.

Chris Penner
@chrispenner.ca

I don't have to serialize some state machine, the code itself and the real Unison values are serialized for me by the language itself. Pretty cool 😎

Chris Penner
@chrispenner.ca

Happy to announce Unison Computing is branching out into consulting! iIf you'd like a hand with your project you'd be hard-pressed to find a better team to help, drop us a line 😎

Unison@unison-lang.org

We have a consulting group, now open to work in a variety of languages, including Scala, Haskell, Rust, Elm, and of course Unison. More details here: www.unison-lang.org/blog/consult... Please boost to help get the word out. And we'd love to hear from you if you're interested in working with us!

unison-lang.orgUnison Computing now has a consulting group · Unison programming languageWe are spinning up a consulting group, now open to work in a variety of languages, including Scala, Haskell, Rust, Elm, and of course Unison. Our goal is a self-sustaining model in which a mix of consulting and product revenue funds development of Unison-based tech well into the distant future. We aim to be cash flow positive as a business in the next 12 months and could use your help in getting there.

Chris Penner reposted

Unison
@unison-lang.org

📰 UCM 1.1.0 is out! * `dependents` can search by variant, not just type or ability name * New built-ins for Argon2id hashing * VS Code actions: Edit Definition & Open on Share * MCP tool: `share-project-info` * Faster bytes ops & improved run command

github.comRelease release/1.1.0 · unisonweb/unisonWhat's Changed Features: The dependents command now work on constructors and ability requests. (#6115) Support for "Edit Definition" and "Open on Share" in the Unison Language VS Code extension v1...
Chris Penner
@chrispenner.ca

I made this tool for managing workshop sessions in tmux and I've used it *hundreds of times* per day every day for 6 years now without any hiccups; if you're looking for a good way to manage your terminal sessions maybe this is it. github.com/ChrisPenner/...

github.comGitHub - ChrisPenner/session-sauce: Shell plugin for managing tmux sessionsShell plugin for managing tmux sessions. Contribute to ChrisPenner/session-sauce development by creating an account on GitHub.
Chris Penner
@chrispenner.ca

I'm learning that the model for the fully-formed shape wasn't too bad, but splitting it up into individually printable parts for assembly is much trickier 🤷‍♂️

Chris Penner
@chrispenner.ca

It's absolutely bonkers how much of modern society is still dependent on staying on hold for 2 hours on an unreliable connection when at any moment your thumb could slip or you could drop the call and there's just no way to get that call back except to wait another 2 hours 😑 #WestJet

Chris Penner
@chrispenner.ca

In any active software project new bugs are always being introduced. Bugs that are important or easy to fix are typically prioritized. This means that as the project ages, the pool of bugs inevitably becomes a majority of the 'difficult to fix' or 'low-priority' variety 😢

Chris Penner
@chrispenner.ca

Want to try a radically innovative programming language? Unison is ready! Unison is approachable, user-friendly, and has a great community of friendly folks :) On top of that it has mind-bending features like serializable function closures and built-in distributed programming tools!

Unison@unison-lang.org

🎉 Unison 1.0 has landed! After years of engineering, design, and community collaboration, we’re excited to announce this milestone! Spread the word!

unison-lang.orgAnnouncing Unison 1.0After years of engineering, design, and community collaboration, we're excited to release Unison 1.0. This version delivers a refined programming workflow and a mature toolchain. Join us as we celebrate this milestone and look ahead to the future of Unison.

Chris Penner reposted

Unison
@unison-lang.org

🚀 New deep dive: Distributed System Engineering in Unison In our latest blog post, take a look at the design of the Volturno library: a distributed stream processing engine built atop Unison Cloud. www.unison-lang.org/blog/volturn...

unison-lang.orgDistributed system engineering in Unison: Volturno · Unison programming languageWe look at the design of Volturno, a streaming engine with exactly-once processing, to illustrate why Unison Cloud is a great enabler for distributed systems builders.

Chris Penner reposted

Unison
@unison-lang.org

📽️ Here's a quick video for anyone just getting started with Unison. The gist of it: install the UCM, create a scratch file in the right place, and have fun programming!

youtu.beStarting the UCM and setting up a scratch fileThis video covers the basics of starting the Unison Codebase Manager (UCM) and writing your first bits of Unison code in a scratch file. We walk through: * Installing Unison on your system (Mac, Linux, or Windows) * Starting the UCM in a working directory * Creating .u scratch files and ensuring the UCM is watching for changes Helpful links: * Install Unison here: https://www.unison-lang.org/docs/quickstart/#step-1-install-unison * Get the UCM Desktop app: https://github.com/unisonweb/ucm-desktop/releases * Join the Unison community: https://www.unison-lang.org/discord
Chris Penner
@chrispenner.ca

I'd really like to speak with whoever thought it was a good idea for the public and private JWK's to be represented by the same type, have the same name, with just a few missing parameters... Ah yes, the presence or absence of this "d" parameter could tank my entire company... seems safe to me :|

Chris Penner
@chrispenner.ca

Even the #Haskell `jose` library doesn't have a separate type for public vs private JWKs, even a phantom type would do the trick. TBH this is just as bad as how generated certs are named key and key.pub; If you tab-complete you'll get the private one every time and there's no `.private` as a hint

Chris Penner
@chrispenner.ca

lol, and when I implemented my own public wrapper over it, and implemented `publicJWKFromPrivateJWK` the AI auto-complete confidently returned the private JWK as-is, asserting that the library "takes care of it for you" which AFAICT is NOT the case... the next generation of app security is cooked.

Chris Penner
@chrispenner.ca

I've spent hours over the last months writing a post about how mutexes suck and everyone should use STM instead; but have come to the realization that even STM is more complex than necessary. What's your decision-making process when building a concurrent and/or parallel system? See mine below 👇

Chris Penner
@chrispenner.ca

My current thoughts: go down the list and use the first approach that you can fit your problem into: * Pipeline processing * CSP * Actors (a half dozen or fewer, statically defined) * STM * Mutexes (only ever use these if you're implementing STM 😆)

Chris Penner
@chrispenner.ca

IMO we shouldn't be trying so hard to solve "the expression problem"; We should make it easy to update existing functions when types change, but it shouldn't always "silently work" with the new type; oftentimes existing functionality needs a human to look over it when there are changes!

Chris Penner
@chrispenner.ca

What do folks out there do for error handling in concurrent tasks in #Haskell? For now I've settled on having an error `TMVar`, then use a `ki` structured concurrency scope which forks all my jobs and ends in an `(Right <$> awaitAll) <|> (Left <$> readTMVar errVar)`

Chris Penner
@chrispenner.ca

TIL callCC's return value isn't rank 2 polymorphic (but you can just route it through Void and use `absurd` to make it rank 2 polymorphic) Spent too long staring at the error wondering why it wasn't working haha. #Haskell github.com/haskell/mtl/...

github.comWhy not use rank 2 polymorphism for `callCC` · Issue #127 · haskell/mtlI think rank 2 polymorphism is a must-have for callCC, or this code will not compile: f :: Int -> String f x = (`runCont` id) $ callCC $ \exit -> do y <- case x of 0 -> exit "error: x == 0" _ -> pu...

Chris Penner reposted

Unison
@unison-lang.org

✨ The new dependents view shows everywhere a definition is used, broken down by category, as a separate card in Unison Share and the Unison Desktop app. Your codebase is a bidirectional graph! You should be able to walk it as such.

Chris Penner reposted

Unison
@unison-lang.org

📽️ New to the Unison workflow? We’re making short videos to walk you through the basics. Follow along here: www.youtube.com/watch?v=QJ1h...

youtube.comInstall and upgrade a library dependencyA walk-through of the process for installing a library dependency and upgrading it. * `lib.install` downloads the library into the `lib` namespace. * `ls lib` will show the current dependencies in the project * `upgrade` with no arguments opens up a version picker. Select the old version first, then the new one. Simple changes can be propagated without developer intervention; more complicated upgrades will prompt the UCM to create a branch for the upgrade process and open up the impacted terms in a scratch file. The resolution process follows the standard workflow for updating Unison code, described here: https://youtu.be/8lCDSCm_rGA.
Chris Penner
@chrispenner.ca

I'm pretty stoked on how well WASM seems to be working for languages that target it (not that there aren't difficulties there). Even more stoked for these updates!

Thomas Steiner@tomayac.com

In #WebAssembly spec news, #Wasm 3.0 is complete 🎉! Read all about it in Andreas Rossberg's article: webassembly.org/news/2025-09....

webassembly.orgWasm 3.0 Completed - WebAssemblyWebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the...
Chris Penner
@chrispenner.ca

It may in fact be a VeryBadIdea™ but I'm extremely tempted to duct tape my soldering iron to my 3D printer and use it to wood-burn the grid lines on the Go board I'm building...

Chris Penner
@chrispenner.ca

Programming languages really need a way to expose functions as "you can import this within this project and tests, but it's not public to other libraries"; somewhere in-between fully public and fully private.