Hacker News Reader

This is awesome! Thank you for sharing it!

I'm wondering though, why do existing tools like Mypy and Pyright not scale for Meta? Is Pyre(fly) being used extensively at Meta? In general what sort of issues did Meta run into?

View on HN

We go into it a bit more here: https://pyrefly.org/en/docs/pyrefly-faq/ The short answer is that the scale of the Python projects we work on is huge. Pyre is the only checker that can scale for our needs today. To bring modern features like type inference and better IDE integration, a full rewrite needed to happen. We are not done just yet, but have been using our massive codebases to test the performance and flexibility of the checker. Thanks for the question!

Reply on news.ycombinator.com