Why is neovim infoview faster than of emacs and code?

Stream: general

[Abdullah Uyu]

By faster, I measure the response time with my eye, and neovim seems to update the infoview faster than emacs and code. Here is a recording that demonstrates the phenomenon:
2024-04-08-21-35-28.mkv

[Richard Copley]

In Emacs, most of the delay is just lsp-mode waiting in case there are more keystrokes, before sending a refresh request. This is lsp-idle-delay (default 0.5 (seconds)) and you can customize it.

[Kevin Buzzard]

Is there an analogous delay in VS Code?

[Abdullah Uyu]

Oh yes, now emacs and code seem equal for me.

[Richard Copley]

Kevin Buzzard said:

Is there an analogous delay in VS Code?

(I can't answer that.)

[Joachim Breitner]

Ok, indeed, that seems a significant difference. Maybe I should look into using neovim for lean development :-)

[Marc Huisinga]

Kevin Buzzard said:

Is there an analogous delay in VS Code?

There's an elaboration delay setting that you can configure (its default is at 200ms, I believe the NeoVim plugin just sets it to 0ms by default).

[Marc Huisinga]

It shouldn't affect just moving the cursor, though

[Marc Huisinga]

I didn't know about this myself, but it turns out that the VS Code InfoView has an additional 'Infoview: Debounce Time' setting that is at 50ms by default to prevent the InfoView from re-rendering when quickly moving the text cursor a lot. If you want the InfoView to update more quickly when the text cursor is moved, you can reduce the debounce time further.

[Julian Berman]

We set the debounce time to 0 by default.

[Julian Berman]

Really that was originally to avoid whatever race condition in the server causes neovim to hang.

[Julian Berman]

But it does certainly make things feel snappier too.

[Julian Berman]

Oh you said that already previously.

[Marc Huisinga]

It's also worth pointing out that the elaboration delay setting is dead code now. The post-incrementality language server uses the server.reportDelayMs command line option to reduce flickering and the edit delay setting is not used at all anymore.