The personal writings of Gavin Gray, when he finds enough characters.https://gavinleroy.com/en-ushttps://gavinleroy.com/writings/posts/errors-diagnostics-interaction/https://gavinleroy.com/writings/posts/errors-diagnostics-interaction/Languages target static, text-based diagnostics by default and make anything fancier an afterthought. This post shows how one technique — Parametric Error Rendering — makes a language's diagnostic system extensible. I build several tiers of type error diagnostic for an MLsub implementation, argue that diagnostics are data visualization, and sketch how to architect a diagnostic system so the technique applies.Mon, 19 Oct 2026 00:00:00 GMThttps://gavinleroy.com/writings/posts/introducing-dark-posts/https://gavinleroy.com/writings/posts/introducing-dark-posts/This is a Dark Theme post. Dark Posts are a subset of blog posts that are even more personal, opinion based, or cynical. Here is why I added them to my site.Tue, 15 Sep 2026 00:00:00 GMThttps://cel.cs.brown.edu/blog/design-space-async-awaithttps://cel.cs.brown.edu/blog/design-space-async-awaitTue, 08 Sep 2026 00:00:00 GMThttps://gavinleroy.com/writings/posts/inlay-hint-confusion/https://gavinleroy.com/writings/posts/inlay-hint-confusion/Many language server implementations use Inlay Hints to show a myriad of information: type hints, navigational hints, contextual hints, etc. AI-autocomplete also uses an inlay-hint-like syntax to show results. In this post I share how this clash in visual notation confused students in our Summer@Brown Introduction to Programming course.Mon, 18 Aug 2025 00:00:00 GMThttps://gavinleroy.com/writings/posts/so-many-companions-and-no-help/https://gavinleroy.com/writings/posts/so-many-companions-and-no-help/Every app now provides some AI assistant to "help you out." But are they actually helping, or merely providing the appearance of intelligence?Sat, 14 Jun 2025 00:00:00 GMThttps://cel.cs.brown.edu/blog/an-interactive-debugger-for-rust-trait-errorshttps://cel.cs.brown.edu/blog/an-interactive-debugger-for-rust-trait-errorsTue, 29 Apr 2025 00:00:00 GMThttps://gavinleroy.com/writings/posts/i-heart-assoc-types/https://gavinleroy.com/writings/posts/i-heart-assoc-types/Associated types in Rust are grossly misunderstood, according to quiz data from the Rust Book Experiment. In this post I explain my view on associated types, when they're useful, and a rule-of-thumb for when a type should be a parameter or associated.Sun, 11 Aug 2024 00:00:00 GMThttps://gavinleroy.com/writings/posts/zuri-kaffee/https://gavinleroy.com/writings/posts/zuri-kaffee/Zurich is one of my favorite cities. Zurich also has an incredible coffee scene. Coincidence? Here are my recommendations for a great cup of coffee in the city.Sat, 30 Sep 2023 00:00:00 GMThttps://gavinleroy.com/writings/posts/julia-dsl/https://gavinleroy.com/writings/posts/julia-dsl/Fri, 20 Aug 2021 00:00:00 GMT