Hacker News: ltratt

New comment by ltratt in "Garbage collection without unsafe code"

ltratt — Wed, 22 Apr 2026 10:19:01 +0000

It would really be good if someone could provide an updated overview of all of the "GCs for Rust" created thus far -- for a while I tried to keep up with them, but there are just too many! When we wrote the Alloy paper, we took Manish's survey as a starting point, and covered as many GCs of different kinds as we could squeeze in [1]. But even then there was no way we could squeeze _everything_ in, and I've seen at least 2 or 3 new ones since (safe-gc is older than the Alloy paper, so I'm not including it in that count)!

[1] https://soft-dev.org/pubs/html/hughes_tratt__garbage_collect...

New comment by ltratt in "Retrofitting JIT Compilers into C Interpreters"

ltratt — Thu, 16 Apr 2026 14:42:25 +0000

> If this project would be able to detect the interpreter hotspots itself and completely automate the procedure, it would be great.

I don't think that's realistic; or, at least, not if you want good performance. You need to use quite a bit of knowledge about your context to know when best to add optimisation hints. That said, it's not impossible to imagine an LLM working this out, if not today, then perhaps in the not-too-distant future! But that's above my pay grade.

New comment by ltratt in "Retrofitting JIT Compilers into C Interpreters"

ltratt — Thu, 16 Apr 2026 07:00:33 +0000

You're quite right that since we're working with LLVM IR, adapting to other languages is probably not _that_ difficult, though these things always end up taking more time than I expect! Since the majority of real-world problems in this area depend on C interpreters, we put our limited resources to that problem. You're also right that "interpreters" is a pretty vague category, and there are other parts of C (and other) programs that could be yk-ified, though I suspect it would be a fairly specialised subset of programs.

New comment by ltratt in "Retrofitting JIT Compilers into C Interpreters"

ltratt — Thu, 16 Apr 2026 06:56:06 +0000

Our fork of LLVM does add a pass, amongst other changes, but we also have to do things like change stackmaps in a way that breaks compatibility. Whether stackmaps in their current incarnation are worth retaining compatibility for is above my pay grade! So some of our changes are probably upstreamable, but some might be considered too niche for wider integration.

Retrofitting JIT Compilers into C Interpreters

ltratt — Wed, 15 Apr 2026 12:00:24 +0000

Article URL: https://tratt.net/laurie/blog/2026/retrofitting_jit_compilers_into_c_interpreters.html

Comments URL: https://news.ycombinator.com/item?id=47777897

Points: 135

# Comments: 26

Some Things I've Learned About Software [video]

ltratt — Mon, 12 Jan 2026 20:00:37 +0000

Article URL: https://www.youtube.com/watch?v=RJgDW2AERr8

Comments URL: https://news.ycombinator.com/item?id=46593441

Points: 1

# Comments: 1

New comment by ltratt in "Async and Finaliser Deadlocks"

ltratt — Wed, 12 Nov 2025 19:36:28 +0000

I'm assuming you're referring to the Python finaliser example? If so, there's no syntax sugar hiding function calls to finalisers: you can verify that by running the code on PyPy, where the point at which the finaliser is called is different. Indeed, for this short-running program, the most likely outcome is that PyPy won't call the finaliser before the program completes!

What Context Can Bring to Terminal Mouse Clicks

ltratt — Thu, 30 Oct 2025 08:27:52 +0000

Article URL: https://tratt.net/laurie/blog/2025/what_context_can_bring_to_terminal_mouse_clicks.html

Comments URL: https://news.ycombinator.com/item?id=45757621

Points: 2

# Comments: 0

What Context Can Bring to Terminal Mouse Clicks

ltratt — Wed, 29 Oct 2025 23:16:51 +0000

Article URL: https://tratt.net/laurie/blog/2025/what_context_can_bring_to_terminal_mouse_clicks.html

Comments URL: https://news.ycombinator.com/item?id=45754389

Points: 3

# Comments: 0

New comment by ltratt in "Garbage collection for Rust: The finalizer frontier"

ltratt — Wed, 15 Oct 2025 21:27:47 +0000

The only way to forbid it would be to forbid creating pointers from `Gc`. That would, for example, preclude a slew of tricks that high performance language VMs need. That's an acceptable trade-off for some, of course, but not all.

New comment by ltratt in "Garbage collection for Rust: The finalizer frontier"

ltratt — Wed, 15 Oct 2025 18:53:42 +0000

We don't exactly want Alloy to have to be conservative, but Rust's semantics allow pointers to be converted to usizes (in safe mode) and back again (in unsafe mode), and this is something code really does. So if we wanted to provide an Rc-like API -- and we found reasonable code really does need it -- there wasn't much choice.

I don't think Rust's design in this regard is ideal, but then again what language is perfect? I designed languages for a long while and made far more, and much more egregious, mistakes! FWIW, I have written up my general thoughts on static integer types, because it's a surprisingly twisty subject for new languages https://tratt.net/laurie/blog/2021/static_integer_types.html

New comment by ltratt in "Garbage collection for Rust: The finalizer frontier"

ltratt — Wed, 15 Oct 2025 16:46:55 +0000

If you've used Chrome or Safari to read this post, you've used a program that uses (at least in parts) conservative GC. [I don't know if Firefox uses conservative GC; it wouldn't surprise me if it does.] This partly reflects shortcomings in our current compilers and in current programming language design: even Rust has some decisions (e.g. pointers can be put in `usize`s) that make it hard to do what would seem at first glance to be the right thing.

Garbage collection for Rust: The finalizer frontier

ltratt — Wed, 15 Oct 2025 12:08:04 +0000

Article URL: https://soft-dev.org/pubs/html/hughes_tratt__garbage_collection_for_rust_the_finalizer_frontier/

Comments URL: https://news.ycombinator.com/item?id=45591149

Points: 144

# Comments: 180

Why Firsts Matter

ltratt — Tue, 16 Sep 2025 21:04:57 +0000

Article URL: https://tratt.net/laurie/blog/2025/why_firsts_matter.html

Comments URL: https://news.ycombinator.com/item?id=45268024

Points: 2

# Comments: 0

Why Firsts Matter

ltratt — Tue, 16 Sep 2025 12:29:45 +0000

Article URL: https://tratt.net/laurie/blog/2025/why_firsts_matter.html

Comments URL: https://news.ycombinator.com/item?id=45261346

Points: 1

# Comments: 0

New comment by ltratt in "LLM Inflation"

ltratt — Wed, 06 Aug 2025 13:18:47 +0000

As Koffiepoeder suggests, since the vast majority of content on my site is static, I only have to compress a file once when I build the site, no matter how many people later download it. [The small amount of dynamic content on my site isn't compressed, for the reason you suggest.]