I think it's ok to prioritize Positron fixes and leave the VSC fix open for a community PR if there's an approach there that would work.

This is really exciting to see! 🎉

I think there is a bit of improvement to do in terms of where the cursor goes in the visual editor after using these. I see that you said there is some difficulty about setting the cursor position in the visual editor 😬 so it's possible this is a big challenge. Take a look at what I mean:

---
title: "Diamond sizes"
format: html
---

```{r}
library(tidyverse)

smaller <- diamonds |>
  filter(carat <= 2.5)
```

• In the source editor, put your cursor at library
• Use Cmd+Enter to step through the lines, including the multiline R statement (notice where your cursor goes after each statement execution
• Switch to the visual editor and put your cursor back at library
• Use Cmd+Enter to try to step through the lines (notice that the cursor doesn't advance enough, which feels especially weird on the empty line)

I also wanted to ask about Python, because I don't see the Python statement range provider being applied, I think? Here is an example to look at:

---
title: "Quarto Basics"
format: html
---

## Matplotlib

For a demonstration of a line plot on a polar axis, see @fig-polar.

```{python}
#| label: fig-polar
#| fig-cap: "A line plot on a polar axis"

import numpy as np
import matplotlib.pyplot as plt

r = np.arange(0, 2, 0.01)
theta = 2 * np.pi * r
fig, ax = plt.subplots(
    subplot_kw = {'projection': 'polar'}
    )
ax.plot(theta, r)
ax.set_rticks([0.5, 1, 1.5, 2])
ax.grid(True)
plt.show()
```

• In the source editor, put your cursor at import numpy
• Use Cmd+Enter to step through the lines, including the multiline Python statement (notice where your cursor goes after each statement execution
• Switch to the visual editor and pur your cursor back at import numpy
• Use Cmd+Enter to try to step through the lines (notice it executes the whole cell, not line by line)

I think there is a bit of improvement to do in terms of where the cursor goes in the visual editor after using these. I see that you said there is some difficulty about setting the cursor position in the visual editor 😬 [..]

I should be able to set the cursor in the visual editor! The cursor placement problem I was having wasn't visual editor specific, it was virtual doc specific.

I will try to improve where the cursor goes after running ctrl+enter.

Aside, to elaborate on the virtual doc + cursor problem I was facing: it would be nice to unify execution in the visual editor and the source editor by creating a virtual doc for the current code block, placing a cursor in the virtual doc, and running the relevent execution-at-cursor command in that virtual doc. Unfortunately, I think virtual docs are just files and are not "open" in an editor, so they don't have a cursor associated with them.

I also wanted to ask about Python, because I don't see the Python statement range provider being applied, I think? Here is an example to look at:

Heard and seen! Thanks for the great example. Indeed the python statement range provider does not seem to be being applied. Also looking at this.

Q: In the source editor, when you Cmd+Enter to step through executing the statements in a cell, what logic does it use to find the index of the start of the next statement?

A: @sharon-wang found it for me: https://github.com/posit-dev/positron/blob/main/src/vs/workbench/contrib/positronConsole/browser/positronConsoleActions.ts#L428 in the advanceStatement function.

I will copy this logic into the Quarto LSP. Maybe ideally Positron would provide a command like "vscode.executeStatementRangeProviderAndGetNextStatementPosition" that returns both a StatementRange and a Position of the subsequent statement so the logic wouldn't have to be duplicated?

I think this was only applying to R documents because of this here:

What happens in the source editor is something like this:

• Positron says, "I have a quarto document and I need a statement range provider for it"
• Quarto extension says, "I have one of those":

• Positron says, "OK, I want you to give me the statement range at position X"
• Quarto extension say, "I will do that":

• Quarto extension fulfills getStatementRange() by executing vscode.executeStatementRangeProvider for the virtual doc (i.e. it asks Positron for the statement range for the underlying virtual doc, since Positron has statement range providers for Python and R):

So it goes back and forth a fair amount!

I think you will want to set up request forwarding in the visualEditorServer function in connection.ts, in codeViewServerMethods; I think what needs to happen for a bunch of the LSP methods (for the statement range provider, F1 help, signature help, etc) is request forwarding. My understanding is that piping through this LSP functionality new to the visual editor will be similar to how completions are piped through.

You can see what LSP functionality the source editor has with all the "providers" in here: