A guide to domain-specific types that make sense.

Luau is the first programming language to put the power of semantic subtyping in the hands of millions of creators. Minimizing false positives One of the issues with type error reporting in tools like the Script Analysis widget in Roblox Studio is false positives. These are warnings that are artifacts of the analysis, and don’t correspond […]

Coming from OCaml, the Rust programming language has many appealingfeatures. Rust’s system for tracking lifetime and ownership allowsusers to safely express...

I have long struggled to understand what a logical relation is. This may come as a surprise, since I have used logical relations a bunch in my research, apparently successfully. I am not afraid to admit that despite that success, I didn't really know what...

Hacky repo to see what the Copilot extension sends to the server

Way back in 2016 I wrote a couple of (now mostly outdated) blog posts talking about how types and declarations are represented in the compiler, and at the time I promised a third installment which would discuss generics. A few of you have asked me about this over the years... Well, I finally got around to starting a write up about how generics work last year, and I think I its finally in good enough shape that I can release the first part of what is going to be a three part series. So here it i...

I don't mean to complain. Doing software engineering for a living is a situation of extreme privilege. But there's something to be said about how alienating it can be at times. ...

This is a post about writing elegant and performant recursive algorithms in Rust. It makes heavy use of a pattern from Haskell called recursion schemes, but you don't need to know anything about that; it's just an implementation detail. Instead, as motivation, I have benchmarks showing a 14-34% improvement over the typical boxed pointer representation of recursive data structures in Rust.

Computer security as a field is met with a persistent criticism:flashy attacks arehot,boring (hard-fought) defenses arenot. Comparedto security, programming ...

I recently decided to confront the fact that I didn't know what "realizability" meant. I see it in programming languages papers from time to time, and could see little rhyme or reason to how it was used. Any time I tried to look it up, I got some nonsense...

Many are well aware of the hazards of race conditions. But what about the benefits?