Arnaud Spiwack
aspiwack.bsky.social
Arnaud Spiwack
@aspiwack.bsky.social
Multi-classed Software Engineer/Constructive Mathematician. Sometimes plays video games sort of fast. Puts topoi in your computer.
Pinned
👋 Welcome (numerous) newcomers.

I'm a Tokyo-based, French, polyglot software engineer, computer scientist, mathematician, and hobbyist speedrunner.

I generally speak of programming languages and their theory, linguistics, science, video games, movies, books. And how the world is very funny indeed.
I'm furious at myself.

I've discovered just this instant that Emacs's Reftex has a command to insert Cleveref's \cref commands. For *years* I've been inserting \ref and manually fixing. I discovered it by mistakenly typing cref in my completion engine.

Don't mind me, I'll be weeping in a corner.
January 27, 2026 at 7:14 AM
J'avoue, ça donne envie.
On est bien chez les matheux y'a des tableaux dans le jardin
January 25, 2026 at 11:05 PM
What a time we live in. On Twitter, what appears to be an official account of French diplomacy seems to be mostly shittposting. x.com/FrenchResponse

I'm torn between “this is no way for a government to behave” and “this is the right way to deal with international trolls in this and that place”.
French Response (@FrenchResponse) / X
French Response (@FrenchResponse) / X
x.com
January 20, 2026 at 12:35 AM
I'm reminded of the French 2012 presidential election. I felt that even those who voted for him were relieved that Nicolas Sarkozy lost. His constant presence and occupation of the media landscape was positively exhausting.
I'm perfectly aware this is by far not the worst thing he's done, but Trump's constant presence - day after day after day - in the lives and headspaces of hundreds of millions of people (billions?), in the US and outside, is so taxing. Every morning, we wake up and have to think about this asshole.
January 20, 2026 at 12:00 AM
Reposted by Arnaud Spiwack
Followed by The Final Countdown played on assorted junk.
youtu.be/B4PSvN3VSyI?...
The Final Countdown (Europe) - Les Fo'Plafonds
YouTube video by Les Fo'Plafonds
youtu.be
January 16, 2026 at 10:19 PM
Reposted by Arnaud Spiwack
What your TL needs right now is the Star Wars Imperial March played on rubber chickens: www.youtube.com/shorts/PQhVt...
Imperial March on Rubber Chicken
YouTube video by Vinheteiro
www.youtube.com
January 16, 2026 at 9:49 PM
Reposted by Arnaud Spiwack
January 14, 2026 at 12:16 PM
Reposted by Arnaud Spiwack
Cantor-Bernstein:
January 12, 2026 at 3:38 AM
Reposted by Arnaud Spiwack
🧪 Here's a science mystery to start the year.

Why are species names for fish and plants appearing in the scientific literature in papers about firefighter injuries, hearing loss and heart attack?

Is it AI? Translation tools? Something else?

nobreakthroughs.substack.com/p/is-this-fi...
January 11, 2026 at 11:34 PM
Diminish a band

Rage Against the Machinima
Diminish a band

Police (Municipale)
Diminish a band

The Placo Maiden
January 12, 2026 at 2:20 AM
I'm quite happy about how this library turned out. I have good hope that it's going to be useful to you. Yes. You.
New year, new blog post. Arnaud Spiwack announces the Pup library. A Haskell library for combinators that do both parsing and pretty printing in a single grammar description. Read and discover the big ideas behind the library's design. www.tweag.io/blog/2026-01...
The quest for grammar combinators: introducing the Pup library
Announcing the Pup library.
www.tweag.io
January 9, 2026 at 7:39 AM
I'd like to contrast this to Dept Q, which I recently watched too. It has a very similar premise: the main character is typically described as “an arrogant prick”. But this series is fantastic, not in small part because the characters feel like characters.
The result is that the season consists mostly of Wednesday being angry and claiming herself perfect, and the rest of the cast lecturing her about it. Over, and over. And it doesn't even amount to anything. If other characters are allowed a modicum of growth, not Wednesday. 2/15
January 8, 2026 at 6:50 AM
Reposted by Arnaud Spiwack
This etymology is wild!

#TIL The English word “average”, originally “custom duty” or “loss in transported goods”, comes from the French “avarie” (meaning “damage to a ship or cargo”) from the Italian “avaria” (same meaning), …
January 7, 2026 at 12:34 AM
There are more nuances to this story that I still don't get either.

If you look at the definition of realisers of A->B, it's not the function space of A to B: it's only those function which are represented by a term. 1/3
I keep thinking about realisability for linear types, and how it seems important that it takes semantics in every presheaf category. Or maybe not all, but all those where the base category admits is a product with a certain category. 1/2
January 7, 2026 at 1:52 PM
I keep thinking about realisability for linear types, and how it seems important that it takes semantics in every presheaf category. Or maybe not all, but all those where the base category admits is a product with a certain category. 1/2
January 6, 2026 at 12:18 PM
Reposted by Arnaud Spiwack
A back-to-work cartoon for @newscientist.com
January 5, 2026 at 11:32 AM
I watched Wednesday season 2. It's not very good.

Mostly it's very boring. It's not that the story is bad, it's pretty ok. But other series or film would run this story in 2 to 3 hours, not 8. 1/15
December 31, 2025 at 8:33 AM
So, Wake up Dead Man, yeah?

It's a very good movie. It's biggest weak point is, ironically, the murder mystery🧵 1/11
December 27, 2025 at 6:52 AM
Gremlins.
December 25, 2025 at 9:07 AM
Reposted by Arnaud Spiwack
Ça vient d'ouvrir ! Ils avaient planqué l'adresse jusque-là, on savait juste que c'est à Arcueil, RER Laplace. J'irai dès que possible. museedujeuvideo.org/fr
Le musée du jeu vidéo
Préserver, comprendre, transmettre : l'héritage du jeu vidéo
museedujeuvideo.org
December 19, 2025 at 11:13 AM
I'd say Capras are kind of the GOAT of the animal kingdom.
December 16, 2025 at 11:48 AM
After 6 years of sitting on the GHC steering committee, my second term is officially over and I haven't sought re-election. It's been a demanding engagement, certainly, but one that I enjoyed a lot. 🙇
December 10, 2025 at 7:26 AM
Reposted by Arnaud Spiwack
A couple years (!) in the making: we’re releasing a new corpus of embodied, collaborative problem solving dialogues. We paid 36 people to play Portal 2’s co-op mode and collected their speech + game recordings.

Paper: arxiv.org/abs/2512.03381
Website: berkeley-nlp.github.io/portal-dialo...

1/n
December 5, 2025 at 6:54 PM
Reposted by Arnaud Spiwack
Indefinite Hyperbolic Numerals
forty-leven
squillion
umpteen
steen
umpty
umpty-ump
umpty-steen
zillion
skillion
jillion
gillion
bazillion
umptillion
kazillion
gazillion
kajillion
gajillion
bajillion
Collected by Stephen Chrisomalis
www.futilitycloset.com/2025/12/05/e...
Extra Large - Futility Closet
Which is bigger, a jillion or a zillion? No one’s quite sure, though we all use these terms pretty readily. In 2016 Wayne State University linguistic anthropologist Stephen Chrisomalis cataloged the f...
www.futilitycloset.com
December 6, 2025 at 4:30 PM
Reposted by Arnaud Spiwack
#Avent2025 2/24 À la recherche des traces des Trente Glorieuses, toujours présentes dans le paysage... Avez-vous déjà vu le pilier bizarre à la sortie de l'A10 à Massy? Maintenant, oui :-)
December 2, 2025 at 3:38 PM