Support variables pane for R (was: Code highlight for R kernel)

[phisanti]

So I am currently using the latest version of Jupyter (v2021.2.0) on my laptop. I find it very cool that I can also use R kernels, even with IntelliSense! yet I might be missing something because I would like to see the variables that I have created and if possible code highlight. Here is a screenshot.

[rchiodo]

Thanks for the suggestion.

We'd likely need help from the R community to get code highlighting and the variable explorer to work.

The variable explorer uses a setting to determine how to query the R kernel for the value of a variable. Specifically this one:

"jupyter.variableQueries": 
                        [
                            {
                                "language": "python",
                                "query": "_rwho_ls = %who_ls\\nprint(_rwho_ls)",
                                "parseExpr": "'(\\w+)'"
                            },
                            {
                                "language": "julia",
                                "query": "whos",
                                "parseExpr": "'(\\w+)'"
                            }
                        ]

If you added a setting for R, you might be able to figure out how get the kernel to return variable information. On top of that the R kernel has to support the jupyter 'introspection' message.

Syntax highlighting is more about VS code supporting R as a default language. In the VS code insiders build, I believe R highlighting should already work.

[greazer]

Thanks for your feedback. The code colorization issue will be addressed once VS Code adds native support for editing notebooks. Please see microsoft/vscode#91987. You can experiment by using VS Code insiders, which defaults to the new notebook experience.

We're keeping this open to track the ability for R to display variables.

[morning-start]

R kernel supports the jupyter 'introspection' message. #710

But what I set could use the variableQueries.

    {
      "language": "R",
      "query": "as.list(.GlobalEnv)",
      "parseExpr": "'(\\w+)'"
    }

    {
      "language": "R",
      "query": "_rwho_ls = %who_ls\\nprint(_rwho_ls)",
      "parseExpr": "'(\\w+)'"
    }

all of these can't work

[rchiodo]

There's likely something that causes a parsing error. You'd have to debug our variable code to figure out why.