frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

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

https://github.com/bugsbugsbux/understanding-j
62•todsacerdoti•8mo ago

Comments

prezjordan•8mo 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•8mo ago
Unintentional humour with how the title got cut off?
pixelpoet•8mo ago
The title stops just short of the
johnisgood•8mo ago
"to the point", I presume, based on its README.
pjmlp•8mo ago
A side effect of the small length available for titles and the whole titles should not be editoralised point of view.
Jtsummers•8mo 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•8mo ago
It's hard to check if titles fit if you use a bot to repost from other sites.
Jtsummers•8mo 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•8mo 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•8mo 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•8mo ago
APL used ¯3 for negative 3; J went underscore to be similar but ascii.
gitroom•8mo ago
Underscore stuff always throws me off - never quite got used to how J does it. Gotta respect the weird choices though.
jbverschoor•8mo ago
Not the same as (Visual) J++. Great IDE btw
vintagedave•8mo 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•8mo 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•8mo ago
Uiua?
binary132•8mo ago
interesting, I have not seen this one
preguntador•8mo ago
12j34 is 12j + 34 or 12 + 34j?
quartern•8mo ago
12 + 34j as per https://code.jsoftware.com/wiki/Vocabulary/Constants#Complex...

Trump is now the president of Venezuela too

https://www.nbcnews.com/world/latin-america/live-blog/venezuela-explosions-trump-maduro-live-upda...
1•nothrowaways•14s ago•1 comments

Asterisk: A small text embedding model for low-resource hardware

https://github.com/rcarmo/asterisk-embedding-model
1•rcarmo•26s ago•0 comments

Intelligence Is a Landscape, Not a Ladder

https://compellingsciencefiction.com/posts/intelligence-is-a-landscape-not-a-ladder.html
1•mojoe•56s ago•0 comments

A Month Exploring Fizzy, "Kanban as it should be"

https://www.zolkos.com/2026/01/02/a-month-exploring-fizzy.html
1•dxs•2m ago•0 comments

Show HN: Byte Lang – a unique programming language with zero optimizations

https://github.com/Morcules/byte-lang
1•morcules•2m ago•0 comments

Seedream 4.0 AI 1-Second Image Generation and Editing Studio

https://seedream4.me/
1•mariolattik•3m ago•0 comments

Show HN: Utilioo- Speak your invoice, get a PDF (built for tradespeople)

https://utilioo.com
1•digi_wares•4m ago•0 comments

Katsuhiro Otomo's Animation Work for Canon's T70 35mm Camera: Japanese Futurism

https://shellzine.net/otomo-canon-t70/
1•zdw•5m ago•0 comments

Bluesky is not the good place

https://www.ms.now/opinion/bluesky-elon-musk-twitter-replacement
1•cf100clunk•6m ago•0 comments

Hardcoded Auth Token in RustFS (CVE-2025-68926)

https://github.com/rustfs/rustfs/security/advisories/GHSA-h956-rh7x-ppgj
1•Tiberium•12m ago•0 comments

Jamal Bryant: The Sound of Covenant This ain't about the dress

https://blacklistedsaint.substack.com/p/jamal-bryant-the-sound-of-covenant
1•BlacklistedSNT•13m ago•0 comments

Plannotator

https://backnotprop.com/blog/plannotator/
2•ramoz•14m ago•0 comments

Dutch amateur weather stations help KNMI boost forecast accuracy

https://nltimes.nl/2026/01/03/thousands-dutch-amateur-weather-stations-help-knmi-boost-forecast-a...
1•giuliomagnifico•20m ago•0 comments

FakeParts: A New Family of AI-Generated DeepFakes

https://arxiv.org/abs/2508.21052
1•ColinWright•20m ago•0 comments

Two Stop Bits – I pushed regular VGA CRTs to 1920x1440 and it worked out

https://twostopbits.com/item?id=7615
2•rbanffy•20m ago•0 comments

Schotter (1968)

https://collections.vam.ac.uk/item/O221321/schotter-print-nees-georg
1•basilikum•20m ago•0 comments

Ambani takes on Coke and Pepsi for India fizzy drink supremacy

https://www.ft.com/content/b2f5a634-1f95-49b7-b4bc-131b5ebc13b8
1•ViktorRay•22m ago•0 comments

Xr0 verifier, guarantee the safety of C programs at compile time

https://xr0.dev
1•Alifatisk•24m ago•0 comments

MetaFun: Compile Haskell-like code to C++ template metaprograms

https://gergo.erdi.hu/projects/metafun/
1•PaulHoule•27m ago•0 comments

Chatbots could be harmful for teens' mental health and social development

https://www.npr.org/2025/12/29/nx-s1-5646633/teens-ai-chatbot-sex-violence-mental-health
2•rbanffy•28m ago•0 comments

Why ChatGPT can't be trusted with breaking news

https://garymarcus.substack.com/p/why-chatgpt-cant-be-trusted-with
1•headalgorithm•28m ago•0 comments

Termix: Web-based platform with SSH terminal, tunneling, file editing

https://github.com/Termix-SSH/Termix
1•thunderbong•32m ago•0 comments

Show HN: 20-Pct-Time

https://github.com/delmarcode/20-pct-time
1•jgautsch•34m ago•0 comments

Show HN: Everyday.live – An MMO you control only through daily text intentions

https://www.everyday.live/
2•joelS•38m ago•0 comments

Trump says US will 'run' Venezuela until 'safe transition can take place'

https://www.bbc.co.uk/news/live/c5yqygxe41pt
6•olalonde•40m ago•2 comments

Brow6el – Terminal Web Browser with Sixel Support

https://codeberg.org/janantos/brow6el
2•bane•40m ago•0 comments

CIA Source Inside Venezuelan Government Helped Track Maduro

https://www.nytimes.com/2026/01/03/world/americas/cia-venezuela-maduro.html
3•ironyman•41m ago•1 comments

Regenerative Software

https://aicoding.leaflet.pub/3majnyfydzs2y
2•chadfowler•41m ago•1 comments

Reflections of a Podcast Power User

https://sajithpai.com/reflections-of-a-podcast-power-user-january-2026/
1•paulpauper•42m ago•0 comments

Google Search Appliance

https://en.wikipedia.org/wiki/Google_Search_Appliance
1•bschne•43m ago•0 comments