LSP for slow-starting (remote) kernels about jupyterlab-lsp

[Zsailer]

If so, I looked into writing a custom NotebookAdapter (from 4.x branch—I'm still stuck in JupyterLab 3.6.x land for awhile), but the interfaces and classes I need (e.g. NotebookAdapter and WidgetAdapter) are not exported.

I see this was already requested:
#774 (comment)

[krassowski]

Would you be willing to export NotebookAdapter and WidgetAdapter in a 4.x release soon

If needs be, sure! But it would be perfect to have a more general solution so maybe it would not be needed?

Does it make sense to fix for the slow, remote kernel case more generally?

Certainly! Is there a way to get kernel_info earlier? If not we could use the one from notebook metadata, right?

[Zsailer]

If not we could use the one from notebook metadata, right?

Yeah, that's right.

In fact, this is what I was attempting to do when writing with my own NotebookAdapter. Determine the language from the Notebook's metadata and begin streaming LSP info right away... then try to ask the kernel for more context once its ready.

I'll work on a PR. 🙂