LSP Development: Add __all__ in ./sage/all.py

[SeanDictionary]

It's enssential to add __all__ list in ./sage/all.py. It'll make LSP development easier.
I'm trying to customize an LSP python-lsp-server for SageMath(see in here). It uses stastic methods to check the imported package.
However, there are no __all__ which caused errors with from sage.all import *. The LSP can't recognize which modulos was imported.

[vincentmacri]

Having a Sage LSP sounds like a great project! I don't know much about this, but one potential hurdle might be that Sage makes use of lazy imports (https://doc.sagemath.org/html/en/reference/misc/sage/misc/lazy_import.html). This is a custom lazy import system. Do you know anything about how that might interact with what you're trying to do here? With PEP810 recently approved, maybe we can eventually get rid of our custom lazy import system in favour of something more standard, but we're still a few years off from that.

[SeanDictionary]

I think lazy imports may not affect LSP. The problem I think is that Sage's directory structure is too complex, but all modules are generally imported via sage.all. This makes it difficult for LSPs to easily trace back to the corresponding function/class through sage.all and thus return the corresponding documentation or usage, etc. As a result, LSPs suffer from high runtime overhead, and may even fail to return results or be down. Having predefined tables, such as __all__, would allow LSPs to quickly query packages that can be imported via sage.all.

[vincentmacri]

If tracking down the source of something imported from sage.all is the issue, then some of the functions documented here might be of interest to you: https://doc.sagemath.org/html/en/reference/misc/sage/misc/dev_tools.html