Simon Willison’s Weblog

Data-driven performance optimization with Rust and Miri (via) Useful guide to some Rust performance optimization tools. Miri can be used to dump out a detailed JSON profile of a program which can then be opened and explored using the Chrome browser’s performance tool. # 9th December 2022, 5:19 pm

Introducing sqlite-loadable-rs: A framework for building SQLite Extensions in Rust. Alex Garcia has built a new Rust library for creating SQLite extensions—initially supporting custom scalar functions, virtual tables and table functions and with more types of extension coming soon. This looks very easy to use, partly because the documentation and examples are already delightfully thorough, especially for an initial release. # 7th December 2022, 11:08 pm

Building a BFT JSON CRDT (via) Jacky Zhao describes their project to build a CRDT library for JSON data in Rust, and includes a thorough explanation of what CRDTs are and how they work. “I write this blog post mostly as a note to my past self, distilling a lot of what I’ve learned since into a blog post I wish I had read before going in”—the best kind of blog post! # 21st November 2022, 7:56 pm

Blessed.rs Crate List (via) Rust doesn’t have a very large standard library, so part of learning Rust is figuring out which of the third-party crates are the best for tackling common problems. This here is an opinionated guide to crates, which looks like it could be really useful. # 7th November 2022, 7:25 pm

mitsuhiko/insta (via) I asked for recommendations on Twitter for testing libraries in other languages that would give me the same level of delight that I get from pytest. Two people pointed me to insta by Armin Ronacher, a Rust testing framework for “snapshot testing” which automatically records reference values to your repository, so future tests can spot if they change. # 31st October 2022, 1:06 am

py2rs. Extremely useful document providing resources for learning Rust followed by an extensive collection of common Python tasks (building a list, opening a file, spawning a thread, running a simple web server) and their Rust equivalents. # 7th October 2022, 5:44 pm

libsql (via) A brand new Apache 2 licensed fork of SQLite. The README explains the rationale behind the project: SQLite itself is open source but not open contribution, and this fork aims to try out new ideas. The most interesting to me so far is a plan to support user defined functions implemented in WebAssembly. The project also intends to use Rust for new feature development. # 4th October 2022, 4:13 pm

Turning SQLite into a distributed database (via) Heyang Zhou introduces mvSQLite, his brand new open source “SQLite-compatible distributed database” built in Rust on top of Apple’s FoundationDB. This is a very promising looking new entry into the distributed/replicated SQLite space: FoundationDB was designed to provide low-level primitives that tools like this could build on top of. # 21st August 2022, 5:40 pm

sqlite-zstd: Transparent dictionary-based row-level compression for SQLite. Interesting SQLite extension from phiresky, the author of that amazing SQLite WASM hack from a while ago which could fetch subsets of a large SQLite database using the HTTP range header. This extension, written in Rust, implements row-level compression for a SQLite table by creating compression dictionaries for larger chunks of the table, providing better results than just running compression against each row value individually. # 9th August 2022, 9:23 pm

The State of WebAssembly 2022. Colin Eberhardt talks through the results of the State of WebAssembly 2022 survey. Rust continues to dominate as the most popular language for working to WebAssembly, but Python has a notable increase of interest. # 20th June 2022, 6:07 pm

Why Rust’s postfix await syntax is good (via) C J Silverio explains postfix await in Rust—where you can write a line like this, with the ? causing any errors to be caught and turned into an error return from your function:

let count = fetch_all_animals().await?.filter_for_hedgehogs().len(); # 15th May 2022, 2:27 pm

jless (via) A really nice new command-line JSON viewer, written in Rust, created by Paul Julius Martinez. It provides a terminal interface for navigating through large JSON files, including expanding and contracting nested objects and searching for strings or a modified form of regular expressions. # 12th February 2022, 3:17 am

Writing a minimal Lua implementation with a virtual machine from scratch in Rust. Phil Eaton implements a subset of Lua in a Rust in this detailed tutorial. # 15th January 2022, 6:29 pm

Announcing Parcel CSS: A new CSS parser, compiler, and minifier written in Rust! An interesting thing about tools like this being written in Rust is that since the Rust-to-WASM pipeline is well trodden at this point, the live demo that this announcement links to runs entirely in the browser. # 13th January 2022, 8:40 pm