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Is Jev the general-purpose classifier we've been waiting for?

https://twitter.com/kris_cvetko/status/2101614168763695308
1•kncvetko•26s ago•1 comments

Dragonfly 2.0: more performance for Redis and Memcached replacement

https://www.phoronix.com/news/Dragonfly-2.0-Released
1•joshcsimmons•1m ago•0 comments

AI and the Destruction of the Creative Commons

https://www.chesterwisniewski.com/post/2026-09-13-ai-is-destroying-the-creative-commons/
1•rakel_rakel•2m ago•0 comments

Show HN: WTF > Auto-check what your coding agent changed

https://github.com/LinusInnovator/wtf
1•Linusinnovator•4m ago•0 comments

Joe Shipman proves marked ruler and compass solves the general quintic

2•jjgreen•12m ago•0 comments

PDF Forgeries Are Surprisingly Rare (2022)

https://gwern.net/blog/2022/pdf-forgery
2•1317•12m ago•0 comments

Hyperbolic Navigation

https://en.wikipedia.org/wiki/Hyperbolic_navigation
1•Eridanus2•16m ago•0 comments

Away Goals Rule

https://en.wikipedia.org/wiki/Away_goals_rule
1•chistev•17m ago•0 comments

Enterprise Cyber Risk Management

https://andersenlab.com/services/cybersecurity-risk-management
1•andersen_lab•23m ago•0 comments

Be Careful with Your Select * Queries

https://notesonsystems.com/articles/why-im-done-with-select-star
1•theanonymousone•28m ago•1 comments

TeaonherChecker

https://teaonher.org
1•thefirstname322•28m ago•0 comments

Leaping Sun Dogs (2016) [video]

https://www.youtube.com/watch?v=KPPaGmtuHCY
1•joebig•31m ago•0 comments

Jev is the fastest-adopted model in AI Gateway history

https://vercel.com/blog/ai-gateway-jev-model-launch
1•flashbrew•32m ago•1 comments

A font that reads what you wrote

https://rohanadwankar.github.io/posts/semfont.html
1•RohanAdwankar•32m ago•1 comments

A deep dive into Jev, TypeSafe's System One model

https://flaviocopes.com/jev/
1•sts153•32m ago•0 comments

CoyoPedal – Full-Size Neural Amp Modeler Captures on an ESP32-S3

https://github.com/dashersw/coyopedal
1•arbayi•32m ago•0 comments

I'm so bad at billiards that I ended up in the hyperbolic plane [video]

https://www.youtube.com/watch?v=kL9BTbIGxLg
1•vismit2000•33m ago•0 comments

MIT Just Proved LLMs Will Stop Getting Smarter, and Money Won't Fix It [video]

https://www.youtube.com/watch?v=6xQ8LQfkBg4
1•bArray•36m ago•0 comments

Show HN: Delightful Cells – reliable AI batch processing for spreadsheets

https://delightfulcells.com
1•sumtsui•38m ago•1 comments

Clawptcha: Reverse Captcha

https://clawptcha.com/
1•Kotlopou•43m ago•0 comments

Neutron Radiation, Emission and Scattering (Neutron Chemistry)

https://www.ossila.com/pages/neutron-radiation
1•peter_d_sherman•44m ago•0 comments

Drop-in Django app to serve a decent LLM-ready documentation site

https://mdjango.chesselink.com/
3•fluxmatix•51m ago•1 comments

I built an extension that hides your personal information from AI

https://github.com/arikchakma/opencloak
2•arikchakma•55m ago•0 comments

Show HN: I-server: Hide server using ICMP reflection/Destination Unreachable

https://github.com/hajoon22/i-server
2•hajoon22•59m ago•0 comments

Benchmarking Wild vs. Mold

https://davidlattimore.github.io/posts/2026/09/18/benchmarking-wild-vs-mold.html
6•birdculture•1h ago•0 comments

Microsoft agentically ports Copilot runtime to Rust for $120K

https://www.theregister.com/devops/2026/09/18/microsoft-agentically-ports-copilot-runtime-to-rust...
5•pjmlp•1h ago•0 comments

Why China is pushing back on US warnings over rapid AI development

https://www.theguardian.com/world/2026/sep/20/why-china-is-pushing-back-on-us-warnings-over-rapid...
5•chrisjj•1h ago•0 comments

Boston to Calcutta Ice Trade Began with One Shipment

https://curiowire.com/article/556
3•thunderbong•1h ago•0 comments

Show HN: Book recommendations with live library availability

https://leafle.nanosheep.net
3•kidnoodle•1h ago•3 comments

Show HN: I built Hacker News alternative and scale to 11,000 users

https://founderstoday.org/
2•dreylord•1h ago•0 comments
Open in hackernews

Understanding-j: An introduction to the J programming language that gets to the

https://github.com/bugsbugsbux/understanding-j
62•todsacerdoti•1y ago

Comments

prezjordan•1y ago
To the author: you can add a .devcontainer directory with a Dockerfile, allowing folks to try this in their browser with GitHub Codespaces

Shameless plug, feel free to copy my setup! https://github.com/jdan/try-j

userbinator•1y ago
Unintentional humour with how the title got cut off?
pixelpoet•1y ago
The title stops just short of the
johnisgood•1y ago
"to the point", I presume, based on its README.
pjmlp•1y ago
A side effect of the small length available for titles and the whole titles should not be editoralised point of view.
Jtsummers•1y ago
It's more an issue of todsacerdoti not checking their submission titles will fit, they do this a lot with their submissions. Abbreviating titles is not frowned upon when they don't fit, I've never had any reverted to something like this submission's title because I (for instance) shortened "United States" to "US" to shave off 11 characters.

In this case, cutting out the superfluous "programming language" part would get you "Understanding-j: An introduction to J that gets to the point" which would fit just fine. When in doubt, include the original title in a comment to explain the edit and let the mods sort it out later.

detaro•1y ago
It's hard to check if titles fit if you use a bot to repost from other sites.
Jtsummers•1y ago
Fair, they're lazy and can't be bothered to fix their bot even after 5 years of submitting messed up titles.
t-writescode•1y ago
From the doc,

  _3                  NB. negative numbers start with underscore
  _                   NB. sole underscore is infinity: a number
  __                  NB. negative infinity
Is this a standard I'm unaware of?
avmich•1y ago
The use of underscore for negative numbers is J's choice, explained e.g. here - https://www.jsoftware.com/docs/help807/jforc/preliminaries.h... .

Explicitly representing infinity, and working with it in some cases, allows to reduce number of exceptions...

Avshalom•1y ago
APL used ¯3 for negative 3; J went underscore to be similar but ascii.
gitroom•1y ago
Underscore stuff always throws me off - never quite got used to how J does it. Gotta respect the weird choices though.
jbverschoor•1y ago
Not the same as (Visual) J++. Great IDE btw
vintagedave•1y ago
I’ve recently come to be fascinated by J.

Twenty years ago, studying my computing degree, one semester we learned J. It was unlike anything I’d used before and the entire class found it confusing. The compiler / environment was reportedly written by one of the professors and it was routine to run into bugs; I remember puzzling through something, going to a tutor, and them just shrugging it off as a J interpreter issue. I never grokked it and simply passed the course.

But it keeps on recurring to me and I pause to think of J at the weirdest times. As I use more and more languages, I’ve become more fascinated by it. Just like Prolog (also one semester, but with a reliable environment.) I want to learn both better.

binary132•1y ago
I’ve been thinking for the past couple of years that the ideal programming language would be something like a combination of a concatenative language (a la FORTH) and an array programming language.
gnubison•1y ago
Uiua?
binary132•1y ago
interesting, I have not seen this one
preguntador•1y ago
12j34 is 12j + 34 or 12 + 34j?
quartern•1y ago
12 + 34j as per https://code.jsoftware.com/wiki/Vocabulary/Constants#Complex...