provide rstudio-like keymaps

Describe the solution you’d like

I’d love it if there was a way to quickly get the key bindings that I (and I suspect many others) have muscle-memoried from RStudio.

Caveats:

• This should only cover R-specific keybindings, such as for devtools::load_all() or R CMD check and not the general-purpose IDE/Editor bindings (i.e. <kbd>CTRL</kbd>+<kbd>1</kbd> for “move to source editor”. VSCode is a different beast and has a completely different design, so it doesn’t make sense for it to behave like RStudio all around. As a heuristic, only those keybindings should be enabled which only make sense inside R projects. If there’s already a native, cross-language VSCode shortcut, that should take precedence.
• Consequently, this should only trigger when "when": "editorLangId == r || editorLangId == rmd && editorTextFocus".
• Some default VSCode keybindings would have to be overwritten (see below).
• The whole thing could maybe be enabled as an option in the setting.

---

Here’s what I have so far (using tasks as per #59):

    {
        "description": "Insert <-",
        "key": "alt+-",
        "command": "type",
        "when": "editorLangId == r || editorLangId == rmd && editorTextFocus",
        "args": {
            "text": "<- "
        }
    },
    {
        "description": "Insert %>%",
        "key": "ctrl+shift+m",
        "command": "type",
        "when": "editorLangId == r || editorLangId == rmd && editorTextFocus",
        "args": {
            "text": "%>% "
        }
    },
    {
        // "description": "Disable (overloaded with above)",
        "key": "ctrl+shift+m",
        "when": "editorLangId == r || editorLangId == rmd && editorTextFocus",
        "command": "-workbench.actions.view.problems"
    },
    {
        "description": "Load all", 
        "key": "cmd+shift+l",
        "command": "r.runCommand",
        "when": "editorLangId == r || editorLangId == rmd",
        "args": "devtools::load_all()"
    },
    {
        "description": "Test",
        "key": "cmd+shift+t",
        "command": "workbench.action.tasks.runTask",
        "when": "editorLangId == r || editorLangId == rmd",
        "args": "Test"
    },
    {
        "description": "Document",
        "key": "cmd+shift+d",
        "command": "workbench.action.tasks.runTask",
        "when": "editorLangId == r || editorLangId == rmd",
        "args": "Document"
    },
    {
        "description": "Check",
        "key": "cmd+shift+e",
        "command": "workbench.action.tasks.runTask",
        "when": "editorLangId == r || editorLangId == rmd",
        "args": "Check"
    },

[bersbersbers]

I found this issue because I fell for an unexpected key mapping collision: in RStudio, <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>S</kbd> runs the source, while that combination in VS Code (and many other tools, compare https://defkey.com/what-means/ctrl-shift-s) is usually used for “File - Save As”. So instead of re-saving my file, I accidentally ran some R code in VS Code due to https://github.com/Ikuyadeu/vscode-R/blob/abd2392d7ef02ea5151b26004368fdedfcc979f4/package.json#L651-L656

In general, I am not sure it is beneficial to emulate RStudio behavior at all. RStudio is only for people working (mostly) with R. VS Code is not only for people who mostly use R, but people also use JavaScript, Python, etc. - often several languages across the same project. So I think I would put more focus on being consistent within the VS Code environment rather than compatibility with RStudio. Please consider that if and when revising any keyboard shortcuts (including <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>S</kbd>). It’s easy for me to unmap*, but new users will always fall for that.

*How? Put this in your keybindings.json:

    {
        "key": "ctrl+shift+s",
        "command": "-r.runSource",
        "when": "editorTextFocus && editorLangId == 'r'"
    },

[bersbersbers]

We could add the suggested keybindings to an RStudio-like keymaps section there? Then users who want them can do a quick copy-paste into their keybindings.json.

You could also add a default-false setting such as config.latex-workshop.bind.altKeymap.enabled in LaTeX Workshop and scope two sets of key bindings to that. That’s how they implement it: https://github.com/James-Yu/LaTeX-Workshop/blob/f6016f6dd15992894935545e25ef1a6a2b6ef411/package.json#L481-L577

I think this is a great idea in general, and it would allow maintaining one (default) set of key bindings with maximum compatibility to VS Code, and another for RStudio users that can be enabled using a single setting.