https://xcancel.com/charliermarsh/status/1884651482009477368

We’re building a new static type checker for Python, from scratch, in Rust.

From a technical perspective, it’s probably our most ambitious project yet. We’re about 800 PRs deep!

Like Ruff and uv, there will be a significant focus on performance.

The entire system is designed to be highly incremental so that it can eventually power a language server (e.g., only re-analyze affected files on code change).

Performance is just one of many goals, though.

For example: we’re investing heavily in strong theoretical foundations and a consistent model of Python’s typing semantics.

(We’re lucky to have @carljm and @AlexWaygood on the team for many reasons, this is one of them.)

Another goal: minimizing false positives, especially on untyped code, to make it easier for projects to adopt a type checker and expand coverage gradually over time, without being swamped in bogus type errors from the start.

We haven’t publicized it to-date, but all of this work has been happening in the open, in the Ruff repository.

All driven by a uniquely great team: @carljm, @AlexWaygood, @sharkdp86, @MichaReiser, @DhruvManilawala, @ibraheemdev, @dcreager.

I’m learning so much from them.

Warning: this project is not ready for real-world user testing, and certainly not for production use (yet). The core architecture is there, but we’re still lacking support for some critical features.

Right now, I’d only recommend trying it out if you’re looking to contribute.

For now, we’re working towards an initial alpha release. When it’s ready, I’ll make sure you know :)

  • esa@discuss.tchncs.de
    1·
    6 hours ago

    For context I’m a scientist doing data analysis and modeling, so my view point is potentially significantly different than most of “the industry”.

    Isn’t most of science also rather big on types, only they use the phrase “units”? If you take an attitude of “I never bother checking my units, I just see if it works or not after the fact”, that’s rather different from the science I learned where checking the types of calculations was considered an important step.

    At some levels it’s even just like colour-coding your wires, helping you not accidentally put ground in the wrong part of the circuit.