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OpenCiv3: Open-source, cross-platform reimagining of Civilization III

https://openciv3.org/
624•klaussilveira•12h ago•182 comments

The Waymo World Model

https://waymo.com/blog/2026/02/the-waymo-world-model-a-new-frontier-for-autonomous-driving-simula...
927•xnx•18h ago•548 comments

What Is Ruliology?

https://writings.stephenwolfram.com/2026/01/what-is-ruliology/
32•helloplanets•4d ago•24 comments

How we made geo joins 400× faster with H3 indexes

https://floedb.ai/blog/how-we-made-geo-joins-400-faster-with-h3-indexes
109•matheusalmeida•1d ago•27 comments

Jeffrey Snover: "Welcome to the Room"

https://www.jsnover.com/blog/2026/02/01/welcome-to-the-room/
9•kaonwarb•3d ago•7 comments

Unseen Footage of Atari Battlezone Arcade Cabinet Production

https://arcadeblogger.com/2026/02/02/unseen-footage-of-atari-battlezone-cabinet-production/
40•videotopia•4d ago•1 comments

Show HN: Look Ma, No Linux: Shell, App Installer, Vi, Cc on ESP32-S3 / BreezyBox

https://github.com/valdanylchuk/breezydemo
219•isitcontent•13h ago•25 comments

Monty: A minimal, secure Python interpreter written in Rust for use by AI

https://github.com/pydantic/monty
210•dmpetrov•13h ago•103 comments

Show HN: I spent 4 years building a UI design tool with only the features I use

https://vecti.com
322•vecti•15h ago•143 comments

Sheldon Brown's Bicycle Technical Info

https://www.sheldonbrown.com/
370•ostacke•18h ago•94 comments

Microsoft open-sources LiteBox, a security-focused library OS

https://github.com/microsoft/litebox
358•aktau•19h ago•181 comments

Hackers (1995) Animated Experience

https://hackers-1995.vercel.app/
477•todsacerdoti•20h ago•232 comments

Show HN: If you lose your memory, how to regain access to your computer?

https://eljojo.github.io/rememory/
272•eljojo•15h ago•160 comments

An Update on Heroku

https://www.heroku.com/blog/an-update-on-heroku/
402•lstoll•19h ago•271 comments

Dark Alley Mathematics

https://blog.szczepan.org/blog/three-points/
85•quibono•4d ago•20 comments

Vocal Guide – belt sing without killing yourself

https://jesperordrup.github.io/vocal-guide/
14•jesperordrup•2h ago•7 comments

Delimited Continuations vs. Lwt for Threads

https://mirageos.org/blog/delimcc-vs-lwt
25•romes•4d ago•3 comments

PC Floppy Copy Protection: Vault Prolok

https://martypc.blogspot.com/2024/09/pc-floppy-copy-protection-vault-prolok.html
56•kmm•5d ago•3 comments

Start all of your commands with a comma

https://rhodesmill.org/brandon/2009/commands-with-comma/
3•theblazehen•2d ago•0 comments

Was Benoit Mandelbrot a hedgehog or a fox?

https://arxiv.org/abs/2602.01122
12•bikenaga•3d ago•2 comments

How to effectively write quality code with AI

https://heidenstedt.org/posts/2026/how-to-effectively-write-quality-code-with-ai/
244•i5heu•15h ago•189 comments

Introducing the Developer Knowledge API and MCP Server

https://developers.googleblog.com/introducing-the-developer-knowledge-api-and-mcp-server/
52•gfortaine•10h ago•21 comments

I spent 5 years in DevOps – Solutions engineering gave me what I was missing

https://infisical.com/blog/devops-to-solutions-engineering
140•vmatsiiako•17h ago•63 comments

Understanding Neural Network, Visually

https://visualrambling.space/neural-network/
280•surprisetalk•3d ago•37 comments

I now assume that all ads on Apple news are scams

https://kirkville.com/i-now-assume-that-all-ads-on-apple-news-are-scams/
1058•cdrnsf•22h ago•433 comments

Why I Joined OpenAI

https://www.brendangregg.com/blog/2026-02-07/why-i-joined-openai.html
132•SerCe•8h ago•117 comments

Show HN: R3forth, a ColorForth-inspired language with a tiny VM

https://github.com/phreda4/r3
70•phreda4•12h ago•14 comments

Female Asian Elephant Calf Born at the Smithsonian National Zoo

https://www.si.edu/newsdesk/releases/female-asian-elephant-calf-born-smithsonians-national-zoo-an...
28•gmays•8h ago•11 comments

Learning from context is harder than we thought

https://hy.tencent.com/research/100025?langVersion=en
176•limoce•3d ago•96 comments

FORTH? Really!?

https://rescrv.net/w/2026/02/06/associative
63•rescrv•20h ago•22 comments
Open in hackernews

Creating C closures from Lua closures

https://lowkpro.com/blog/creating-c-closures-from-lua-closures.html
60•publicdebates•1mo ago

Comments

widdershins•1mo ago
This doesn't seem like something that should require generating assembly to solve. Couldn't `CALLBACK` just return a table, which contains both the userdata pointer to `REAL_CALLBACK` and a value for `findex`, eliminating the global variable? Then `Add` could extract that. You could even make the table returned by `CALLBACK` callable in Lua with a metatable.

Or, if you're worried about performance/memory, you could allocate a struct for `CALLBACK` to return as userdata, containing the function pointer and `findex`. If you made a little allocator for these it would be extremely fast.

I'm sure I'm missing things, but the solution you chose feels like the nuclear option.

comex•1mo ago
The code is passing the function pointers into Win32 APIs, so the caller side isn’t controlled; the callbacks have to work as native C function pointers.

This was probably posted in response to this other link from two days ago, which is about about JIT-compiling wndproc callbacks in particular; the comments discuss the “proper” way to do it, which is to use GWLP_USERDATA:

https://news.ycombinator.com/item?id=46259334

At least, that’s the proper way to do it if you control the entire application. But for what’s apparently a thin wrapper that exposes Win32 APIs directly to Lua, I can understand picking an approach that makes life easier for the Lua code author, even if it’s hackier under the hood. It also avoids the need to write custom behavior for each API.

publicdebates•1mo ago
It was inspired by that post, but not in response to it. Over the 3 or 4 months that I took writing lowkPRO, one of the features I'm most proud of is this, the ability for it to create C callbacks on the fly that just call Lua callbacks and return the value to C. And I would argue that it's not hacky but just well-engineered. After all, everything compiles to assembly at the end of the day, right?
CodesInChaos•1mo ago
Well designed C APIs have a context/userdata parameter on their callbacks, which is registered and stored alongside the function pointer. Unfortunately WNDPROC lacks this parameter.

GWLP_USERDATA should be the best option, though the API for setting it and setting the WNDPROC being separate looks error prone.

publicdebates•1mo ago
The bigger problem is that I would have to automate this for every callback type in the Windows API, and there's no guarantee that all of them follow the same 2 or 3 patterns for passing the context pointer into the callback. This solution works great, even if it is a bit wasteful of the ctx ptr.
psychoslave•1mo ago
What’s the thing emulating so much activity around closures lately?

https://news.ycombinator.com/item?id=46228597

https://news.ycombinator.com/item?id=46259334

Also talking about the Knuth boy/man test: https://news.ycombinator.com/item?id=46020151

Not a bad thing, but that really question if there is some active micro-

shakna•1mo ago
Why VirtualAlloc?

Lua has its own allocator, which will also collect for you. lua_newuserdata. At the expense of having to set executable yourself, but without all the inbuilt inefficiencies the article points out.

publicdebates•1mo ago
Can you set arbitrary memory allocated by malloc (e.g. HeapAlloc in Windows) to executable, via VirtualProtect or something else? If so, that's news to me. I thought it had to be memory allocated by VirtualAlloc only.

That said, I'm not sure that solution beats out this one. I'm using a linked list on top of an arena allocator in practice, which means allocations happen once every 0x10000 bytes. (A single C closure of mine takes up exactly 16 bytes, which includes the pointer to the next linked list node. I'm very happy with how it's designed.)

shakna•1mo ago
Lua lets you set the allocator, so you don't have to manage the lifetime.

    void lua_setallocf (lua_State *L, lua_Alloc f, void *ud);
publicdebates•1mo ago
Two problems with that.

First, it would mean that all Lua objects would be allocated in memory that's potentially executable. That might not necessarily be more of a security issue than the app inherently allows, but at least it's wasteful.

Second, I'm not entirely sure it's a good idea to have C callbacks be collectable, which is why currently they aren't, and you have to free them manually via my winapi.freecallback function. This is part of the inherent issue in the fact that the Windows API has its own concept of lifetimes that are different than Lua's collection visibility. I would like to try to tie them together if possible one day, I'm just not entirely sure how yet.

ufo•1mo ago
I wonder if there would be a way to piggyback on top of GCC's nested function extension. It does something a little bit similar, with the dynamically generated functions.
halayli•1mo ago
I feel libffi is better suited and supports most platforms.
lkuty•1mo ago
Tsoding made a video about it : https://www.youtube.com/watch?v=0o8Ex8mXigU
rurban•1mo ago
The ffcall library even more
halayli•1mo ago
wasn't aware of ffcall, it's definitely a better fit
not_a9•1mo ago
Fun fact: LuaJIT FFI actually has a similar feature. You can do funky things like detour hooking with this functionality too.

https://luajit.org/ext_ffi_semantics.html