Everyone knows Wasm is a stack machine. Wikipedia says so, the official Wasm design specification says so, you get it. I thought so too. That is, until I started writing Wasm code – not compiling for Wasm, but writing the instructions by hand. And I found out that there exists a major difference between Wasm and all...

I needed to convert file status flags between operating systems yesterday. They are the values you pass as the second argument to open – O_NONBLOCK, O_NOATIME, O_SYNC, O_DSYNC, and so on: int open(const char *path, int flags, /* mode_t mode */ ); So naturally I wrote it like this: int dst_flags = 0; if (src_flags &...

The appearance of Mythos – a private LLM allegedly capable of finding a multitude of 0-days – has made people concerned about being denied powerful tools. This seems to be a turning point in the mainstream discourse, and it motivated me to complete the think piece I’ve been meaning to write for a while. I have a...

In case you’re unaware, I’m not a developer. I’m actually an autistic catgirl annoyed by suboptimal use of computing power, and fixing that happens to involve programming. Crucially, it also includes discussing foundational technology with people behind the scenes, and apparently that makes me more aware of social...

What came to your mind when you read “hash functions” in the title? If you’re pragmatic, you probably remembered SHA-256 or MD5. Those are cryptographic hash functions, and they work fast and well for arbitrary inputs, even if they are supplied by malicious actors. Or at least they’re designed to. That’s the exact...

This is a rant about how broken everything Web is based on is. You know, the usual. No offence intended towards framework developers, I’m glad this technology exists, but I’m sure you know this feeling. It gets too much sometimes. I’ve been meaning to improve this blog’s technology for a while. It’s held together by...

Minecraft generates a bedrock floor at the bottom of the world from a random noise. Since it’s random, it can contain naturally generated unescapable regions – prisons. While small prisons are common, larger ones are hard to find – a Minecraft world is about 60 million by 60 million blocks, so locating these boxes...

Two years ago, I was pondering ways to enhance borrowck with proof-based analysis. At the time, I was only aware of formal verification tools for functional languages, while Rust is impure. For the purposes of borrow checking, though, we can almost pretend that impurity doesn’t exist, with the notable exception of...

The story goes like this. ComputerCraft is a mod that adds programming to Minecraft. You write Lua code that gets executed by a bespoke interpreter with access to world APIs, and now you’re writing code instead of having fun. Computers have limited disk space, and my /nix folder is growing out of control, so I need...

Last year, Lemire wrote about an optimized variation of the Euclidean algorithm for computing the greatest common divisor of two numbers, called binary Euclidean algorithm or Stein’s algorithm. It’s a best-of-class implementation, though it’s currently only used by libc++. The post also briefly mentions the extended...

Functions in binary files need to have unique names, so Rust needs to decide what to call its functions and statics. This format needs to be standardized so that debuggers and profilers can recover the full names (e.g. alloc::vec::Vec instead of just Vec). About a month ago, Rust switched to symbol mangling v0 on...