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An open letter to the Nvidia Board of Directors

https://standwithjensen.com/
3•iLuddite•4m ago•0 comments

Cybercab for Personal Use, for Sale

https://twitter.com/robotaxi/status/2121384435241402737
1•denysvitali•4m ago•0 comments

Anthropic Launches 'Claude for Manufacturing'

https://www.manufacturingdive.com/news/anthropic-launches-claude-for-manufacturing/874303/
1•olalonde•9m ago•0 comments

Weight Space Programming cntd (more than model card)

https://harlyn1.github.io/weight-space-advising-logs/
1•sixdimensions•10m ago•0 comments

Tell HN: Google Search to start locking down search behind a login wall

2•exploraz•11m ago•0 comments

Jensen Huang commemorative plaque gone from the Denny's where he founded Nvidia

https://nypost.com/2026/11/13/business/jensen-huang-commemorative-plaque-gone-from-famed-dennys-w...
3•Michelangelo11•17m ago•0 comments

iPhone-backup-sync: Incremental iPhone DCIM backup for Windows

https://github.com/mahdis24/iphone-backup-sync
1•mahdi_s24•17m ago•0 comments

Our new search index: Caffeine (2010)

https://developers.google.com/search/blog/2010/06/our-new-search-index-caffeine
1•measurablefunc•19m ago•0 comments

Show HN: Live map of U.S. flights during tonight's FAA nationwide ground stop

https://grounds.top/
4•gvsi•20m ago•0 comments

Jensen Huang Fu**ed Everybody

https://www.theringer.com/2026/11/12/tech/jensen-huang-nvidia-ceo-resignation-chinese-spy-stock-m...
2•cdrnsf•24m ago•0 comments

Who needs sex? Kelp reproduce asexually when no mate is nearby

https://www.nature.com/articles/d41586-026-03665-0
1•titusblair•26m ago•0 comments

FaceStealer Cryptocurrency Theft Scheme

https://www.fbi.gov/investigate/cyber/facestealer-cryptocurrency-theft-scheme
3•nomilk•28m ago•0 comments

Terminal borders that don't cost a cell

https://www.joshka.net/cell-borders/
16•vinhnx•31m ago•3 comments

The anti-marketing aspect of the Gemini network

https://ploum.net/2026-11-12-anti-marketing-gemini.html
2•birdculture•32m ago•0 comments

How Not to Build a Music Player

https://alichraghi.github.io/blog/how-not-to-build-a-music-player/
3•vinhnx•33m ago•0 comments

Complex Systems Won't Survive the Competence Crisis

https://twitter.com/palladiummag/status/2015572679064170828
2•barry-cotter•33m ago•1 comments

FAA tees up $875M AI tool to help manage air traffic congestion

https://arstechnica.com/ai/2026/09/faa-tees-up-875m-ai-tool-to-help-manage-air-traffic-congestion/
8•brandonb•35m ago•3 comments

Meta Testing New Prediction-Market App with Employees

https://www.wsj.com/tech/meta-testing-new-prediction-market-app-with-employees-bf7bacb2
3•JumpCrisscross•37m ago•0 comments

Using Claude Opus 5.5 as your daily driver for knowledge work

https://claude.com/resources/articles/using-claude-opus-5-5-as-your-daily-driver-for-knowledge-work
1•geoffbp•39m ago•0 comments

Drones over UK skies: US Air Force launches urgent response

https://www.express.co.uk/news/uk/2266117/drones-uk-skies-us
4•irthomasthomas•39m ago•0 comments

Mountain growth spurts may have sparked complex life on Earth

https://science.ubc.ca/news/2026-11/mountain-growth-spurts-may-have-sparked-complex-life-earth
1•geox•41m ago•0 comments

Opus 5.5 is probably still nerfed

https://micjm.com/blog/opus-5.5-after-fable/
1•seizethecheese•43m ago•0 comments

Lying to Zed to get its remote server running on FreeBSD

https://hayzam.com/blog/03-lying-to-zeds-remote-editor/
2•arch1e•43m ago•0 comments

Tell HN: Cloudflare's abuse report form is a blank page

2•basilikum•44m ago•5 comments

QuAIA: An open-source team of AI agents that handles the whole test process

https://quaia.dev/
1•partarstu•45m ago•0 comments

Ground stop ordered for all airports nationwide for 'reasons of safety'

https://www.nbcnews.com/news/us-news/faa-orders-nationwide-ground-stop-departing-flights-reasons-...
5•goryramsy•49m ago•1 comments

US National Weather Service reports nationwide internet, communications issues

https://www.reuters.com/technology/us-national-weather-service-reports-nationwide-internet-commun...
15•ck2•51m ago•5 comments

Nvidia's Huang turns to Paul Weiss, law firm that inked deal with Trump

https://www.reuters.com/legal/transactional/nvidias-huang-turns-paul-weiss-law-firm-that-inked-de...
2•tartoran•51m ago•0 comments

Claude Meetings

https://claude.com/resources/articles/claude-meetings
54•hmokiguess•59m ago•40 comments

Which Targets Are Overheated?

https://insights.convoke.bio/articles/target-heat-index
3•ray__•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...