Upgrade `dmypy` to a language server (LSP)

Feature

I would like for dmypy to be a fully fledged language server. Obviously it would only support diagnostics (which would make this much simpler). But this would be very convenient from an editor point on view given the direction editor tooling is going.

Could probably use something like https://github.com/openlawlibrary/pygls to handle the low level details of LSP.

Pitch

Most editors and their plugins shell out and call mypy. But this can be quite slow on some projects since it needs to cold start every time (except for .mypy_cache).

Commencez par lire l’implémentation de dmypy et la spécification LSP, puis évaluez pygls comme bibliothèque de bas niveau proposée. Définissez comment dmypy doit exposer les diagnostics via LSP et identifiez les tests d’éditeur ou de protocole nécessaires pour vérifier le serveur. Le travail est terminé lorsque dmypy fonctionne comme un serveur de langage qui fournit des diagnostics aux éditeurs.