Hacker News: pcwalton

New comment by pcwalton in "JIT: So you want to be faster than an interpreter on modern CPUs"

pcwalton — Tue, 14 Oct 2025 18:27:26 +0000

Sure, but the relevant comparison isn't between languages: it's between a state-of-the-art JIT implementation of one language and a likewise-state-of-the-art AOT implementation of the same language. Unfortunately there aren't many examples of this; most languages have a preferred implementation strategy that receives much more effort than the other one.

New comment by pcwalton in "JIT: So you want to be faster than an interpreter on modern CPUs"

pcwalton — Tue, 14 Oct 2025 18:25:38 +0000

I believe HotSpot is usually faster than GCJ.

New comment by pcwalton in "Perfecting anti-aliasing on signed distance functions"

pcwalton — Mon, 04 Aug 2025 17:46:58 +0000

Mathematically, what you want to do here is to calculate the area of the pixel square (or circle; however you want to approximate it) that the shape covers. In this case a linear ramp actually approximates the true value better than smoothstep does. (I had the derivation worked out at some point; I don't have it handy, unfortunately.) Of course, beauty is in the eye of the beholder, and aesthetically one might prefer smoothstep.

By the way, since the article mentions ellipse distance approximations, the fastest way to approximate distance to an ellipse is to use a trick I came up with based on a paper from 1994 [1]: https://github.com/servo/webrender/blob/c4bd5b47d8f5cd684334... Unless it's changed recently, this is what Firefox uses for border radius.

[1]: http://mesh.brown.edu/taubin/pdfs/Taubin-tog94.pdf

New comment by pcwalton in "Canyon.mid"

pcwalton — Sun, 15 Jun 2025 19:25:07 +0000

Your note taking app doesn't need AI, but it also doesn't need OLE, which represented an equally hot buzzword ("software componentry") of the 90s that Microsoft was trying to shoehorn into everything.

Every generation has its hype cycle; it's nothing new.

New comment by pcwalton in "Writing into Uninitialized Buffers in Rust"

pcwalton — Wed, 21 May 2025 22:53:40 +0000

jcranmer is correct and pointer provenance-related issues are not "boxed and contained". Start here: https://www.ralfj.de/blog/2020/12/14/provenance.html

New comment by pcwalton in "Evolution of Rust Compiler Errors"

pcwalton — Fri, 16 May 2025 17:43:17 +0000

My recollection is that Brian Anderson, who came from the C# world, was an early advocate of the easily-googlable error codes that Microsoft compilers use a lot, and pushed to get them in. That was a good call. (In general Brian had a lot of behind-the-scenes positive influence on Rust: my favorite brson-ism is "if the code doesn't have a test it doesn't exist".)

New comment by pcwalton in "Evolution of Rust Compiler Errors"

pcwalton — Fri, 16 May 2025 17:40:15 +0000

When I was first developing early versions of rustc I was really fascinated with Clang's effort at good error messages, which was helping it gain traction vs. GCC at the time, and I tried to start the Rust compiler project off on the right foot. I'm really glad that the Rust compiler dev community has continued to value great error messages: they're the UX of a compiler, and are every bit as important as UX of any other app.

New comment by pcwalton in "Designing Cities for Families"

pcwalton — Fri, 16 May 2025 15:16:31 +0000

The modal urbanist who lives in the suburbs is usually just someone who wants to be able to have the lifestyle they want without a commute to work. Someone who works at Google in Mountain View but would prefer not to have to drive everywhere, for example. Or, in your example, someone who works at the Pentagon but doesn't want to have to commute from Maryland (or D.C.) in order to live in a walkable area.

New comment by pcwalton in "Designing Cities for Families"

pcwalton — Thu, 15 May 2025 16:52:38 +0000

But urbanists do live in cities? San Francisco proper is, like, the origin of the YIMBY movement. Searching for "baltimore yimby" on Google brings up a lot of advocacy, like this: https://www.thebaltimorebanner.com/community/housing/baltimo...

New comment by pcwalton in "RIP Usenix ATC"

pcwalton — Thu, 15 May 2025 05:19:24 +0000

Yes, all Rust papers anyone tried to submit were consistently rejected up until Rust became popular, at which point Rust became the hot new thing in applied programming language research. Academic PL is very insular (to its detriment, I'm convinced).

New comment by pcwalton in "How Riot Games is fighting the war against video game hackers"

pcwalton — Sun, 04 May 2025 19:39:29 +0000

You can raise the cost of cheating so that cheating kids will get annoyed and go cheat in some other game or scroll TikTok or whatever. We're not exactly dealing with nation-states here.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Sat, 03 May 2025 04:00:34 +0000

Yeah, sorry, my mistake. GitHub did report on the SO survey [1], which probably led to my mixup.

Anyway, Rust was still the "most admired" language in 2024 [2].

[1]: https://github.blog/developer-skills/programming-languages-a...

[2]: https://survey.stackoverflow.co/2024/technology#admired-and-...

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:51:52 +0000

Yes, you have correctly pointed out that there are some developers who are unhappy with Rust.

I don't really care to have an argument as to whether "Rust has peaked" or not. Rust is the same language now as it was in 2023, and 2022, and 2021, etc., and developers liked it then. That's all.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:29:53 +0000

I'm happy to revise what I said from "Rust keeps winning" to "Rust continually won" if you want to nitpick my choice of verb tenses. It refutes the idea that the "developer joy is pretty low" either way.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:20:05 +0000

Because "else" technically includes "comptime_float", so that case is handled, just not in the way that's expected.

One of the downsides of comptime over generics is that, because it's low-level and procedural instead of high-level and declarative, things like automatically inserting coercions become harder.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:14:49 +0000

https://github.blog/developer-skills/programming-languages-a...

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:09:13 +0000

> Rust is still popular but it turns out the developer joy is pretty low.

I mean, Rust keeps winning the "most loved" language contest on GitHub, so it seems someone likes it.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:07:31 +0000

This is a good point. Zig is practically optimized for this: comptime is extremely dynamically typed compared to actual generics, and the lack of memory safety is often "a breath of fresh air"--until you have to actually fix bugs (including security bugs) resulting from it.

New comment by pcwalton in "Reflecting on a Year of Gamedev in Zig"

pcwalton — Fri, 02 May 2025 19:06:03 +0000

> It's not a great hobby language but it is a fantastic professional language,

I never thought I'd live to see the day when someone would say this. The first 5 years of Rust were all "this is interesting for hobby projects but nobody will ever adopt this in industry".

New comment by pcwalton in "Office is too slow, so Microsoft is making it load at Windows startup"

pcwalton — Thu, 01 May 2025 21:30:56 +0000

If Microsoft had adopted this attitude, then by now Excel's market share would probably be 0% and Google Sheets' would be 100%. Microsoft doesn't add features because they like bloated software; they add features because the market demands them, and the market demanded support for more than 65,535 rows.