Support for $ autocompletion in nested lists

[Ben-Drucker]

Is your feature request related to a problem? Please describe.
Sometimes, I'm using nested lists, for example

l <- list(a1 = list(b = 3, c = list(1, 2, d = list(e = 3))), a2 = 4, a3 = 5)

The existing autocompletion feature when using the $ selector is very handy to bring up the possible elements:

However, if one tries to use the $ operator on a sublist, no autocompletions are available:

If I'm manipulating a nested list from, say, an external package, I don't always know what the elements of a nested list are (and they're not always documented). So it would be nice to see them directly within the code editor.

Perhaps this is because autocompletions only appear when an object is evaluated. Hence, a potential workaround is assigning l$a1 to an intermediate variable and using $ on that.

Describe the solution you'd like
When selecting elements of a nested list using multiple $, the elements of the nested list should appear as auto-suggestions.

Describe alternatives you've considered
One can assign an intermediate, temporary variable and then use the $ selector on that. Obviously, one could also print the list of elements in the terminal, but the presentation is much nicer when it's integrated into the code editor.

Additional context
I've really enjoyed using this extension! It's incredibly useful :)

[renkun-ken]

If you enable r.useWebServer which starts a http web server via {httpuv} and communicates with vscode-R session watcher, using $ on a nested list should work.

[github-actions]

This issue is stale because it has been open for 365 days with no activity.