frontpage.
newsnewestaskshowjobs

Open Source @Github

fp.

In-App Avatar Integration

https://www.elias-schoko-shop.de/
1•eschwalme•1m ago•1 comments

standard.site

https://standard.site/
1•soheilpro•1m ago•0 comments

We found a bug in the hyper HTTP library

https://blog.cloudflare.com/hyper-bug/
1•soheilpro•2m ago•0 comments

Democratic Tech Alliance

https://democratic.technology/
1•doener•3m ago•0 comments

Hospitals switched to pen and paper to defeat a national cyber-attack

https://www.bbc.co.uk/news/articles/c4gyk756mzlo
2•mmarian•4m ago•0 comments

Show HN: Founder Pass – 6 indie dev tools lifetime for $14 (first 10 only)

https://xiaohou2503687-design.github.io/shipfast-oss/founder.html
1•shipfastcli•4m ago•0 comments

Metasearch: A self-hosted metasearch engine

https://github.com/tiagozip/metasearch
1•mrunix•8m ago•0 comments

Why AI Problems Are Becoming Philosophical Problems

https://kunyuan.substack.com/p/07concept-entrywhy-ai-problems-are
1•hufdr•9m ago•0 comments

ggsql 0.4.1: new release adds spatial plotting and in-layer aggregation

https://opensource.posit.co/blog/2026-06-23_ggsql_0_4_1/
1•thomasp85•9m ago•0 comments

Feedback on the logo for my programming language, Lopo

https://github.com/dominexmacedon-docs/lopo-docs/blob/main/lopo.png
1•dominex•12m ago•0 comments

Wlog: Claude Code token/cost/tool dashboard, single binary, no Grafana

https://github.com/openwong2kim/wlog
1•wong2kim•13m ago•0 comments

Watch me build out an 80s style BBS over SSH

1•buffer_overlord•17m ago•0 comments

A1 Road Collision Density Visualisation

https://visquill.com/gallery/uk-a1
1•zeristor•17m ago•0 comments

Show HN: Algorithm-free video hosting that doesn't recompress your master

https://longplayplatform.com/
1•longplay•17m ago•0 comments

The Startup Graveyard – what killed 16 startups

https://kasspian.com/graveyard
2•izhonline•18m ago•1 comments

Modellot – Plain language in, ODCS data contracts out (EU Data Act compliant)

https://www.modellot.com/
1•sasanin•20m ago•0 comments

Semantic Search in Under 3MB

https://blog.lukesalamone.com/posts/creating-tiny-semantic-search/
1•salamo•20m ago•0 comments

Show HN: Describe a research topic, get a daily-updated ArXiv/S2 dataset

https://fineset.io
1•dangerlego5•21m ago•0 comments

What's in America's Code?

https://www.boozallen.com/expertise/cybersecurity/whats-in-americas-code.html
1•ironyman•25m ago•0 comments

Show HN: Enigma Simulator – Encrypt Like WWII

https://enigma-simulator.waibsite.app/
2•dreamcin•30m ago•0 comments

Change 'arxiv' to 'autoarxiv' in URL to run agent on any paper

https://digg.com/tech/m9r4hegw
2•weinzierl•31m ago•0 comments

The Traditional Vi

https://ex-vi.sourceforge.net/
2•exvi•32m ago•0 comments

Gemini models increasingly stucking in thinking loop

4•StizzurpXDD•32m ago•5 comments

Reject Agility, Embrace Specification

https://lewiscampbell.tech/blog/260622.html
2•LAC-Tech•34m ago•0 comments

vilearn – an interactive vi tutorial

https://git.sr.ht/~libele/vilearn
1•exvi•34m ago•0 comments

Microsoft accidentally kills epic Outlook email threads

https://www.theregister.com/personal-tech/2026/06/22/microsoft-accidentally-kills-epic-outlook-em...
1•01-_-•35m ago•0 comments

Tencent Is Said to Mull Exits from Game Studios Like Marvelous

https://www.bloomberg.com/news/articles/2026-06-23/tencent-in-talks-to-offload-marvelous-and-othe...
2•01-_-•35m ago•0 comments

Building Blocks of GenAI Product Evaluation

https://yinghonglan.substack.com/p/building-blocks-of-genai-product
1•rented_mule•35m ago•0 comments

Will Apple Pull a SpaceX?

https://hitesh.in/2026/apple-ai-inference-silicon/
3•antrix•36m ago•1 comments

PDFWix Free online PDF and document conversion Tool

2•PDFWix•42m 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...