rud.is

Microsoft’s newfound desire to make themselves desirable to the hipster development community has caused them to make many things [open](https://github.com/Microsoft/) and/or free of late. One of these manifestations is [Visual Studio Code](https://code.visualstudio.com/), an [Atom](https://atom.io/)-ish editor for us code jockeys. I have friends at Microsoft and the Revolution R folks are there now, so I try to give things from Redmond a shot more than I previously would, especially when they make things for Mac.

VS code is so much like Atom (or even [Sublime Text](http://www.sublimetext.com/)) that I won’t go into a full review of it. Suffice it to say it has a file selector pane, editor panes, output panes, snippets, theme support and is pretty extensible. One requirement I appreciate is that it forces you to think of code in terms of projects (you select a directory to edit in) and I also appreciate that they made git a first-class citizen.

Since I do not spend much time building large, compiled applications (this—along with web apps—seems to be VS Code’s sweet spot) there isn’t much initial appeal for me. It also lacks the “intellisense” support for the main language I use (R) so I’m left with basic syntax highlighting (the 90’s called and want their basic editor capabilities back).

None of that would initially drive me away from using something like VS Code and I may end up using it for HTML/CSS/JavaScript projects or even fire it up when I need to do some work in Python or Go. But I won’t be using it for R any time soon. While the aforementioned lack of “intellisense” for R is an issue, I don’t rely on the auto-completion for R but it does occasionally speed up typing and definitely helps with the more esoteric function definitions in equally esoteric packages.

The biggest show-stopper for VS Code is the lack of REPL (a read-eval-print loop) for R. I can fire up an R script in Sublime Text or even Atom and run individual lines of code that are executed in an R session that runs in the background and outputs in an editor pane. It works well but it is (unsurprisingly) a far cry from the tight integration of similar functionality in RStudio. VS Code can run R scripts (it just runs the code through R as you would at the command-line) but has no REPL for R, which means you end up executing the entire script as you go along. No saved state (more on that in a second) means that the beautiful data frame your code created that took 10 minutes to build will take 10 minutes to build every time you tweak model parameters or ggplot2 aesthetics. Granted, you could call R with `–save` but then you have to check for the presence of data structures in your code (so you might as well be programming in non-interactive Python).

An offshoot of the details behind this show-stopper is that you do not get graphics output in a window. You get a single PDF of all plots, just as you would if you ran the R script at the command-line. If you’ve been spoiled by RStudio or even cutting and pasting code from an editor into the R GUI, you will immediately miss the graphics viewer pane.

Unless Microsoft (or some community contributors who desperately want to use R in VS Code for some reason) add some of this functionality to VS Code (including support for seamlessly spinning R scripts and knitting R markdown documents), I cannot recommend using to anyone in the R community.

Having said that, here’s the `tasks.json` configuration if you want to be able to hit `Command-Shift-B` in an R script in VS Code and have it execute and display the output. This configuration is for the official R Project build of R and should work even after a R version upgrade).

{
	"version": "0.1.0",
	"command": "/Library/Frameworks/R.framework/Resources/bin/R",
	"showOutput": "always",
	"args": [
		"--no-restore",
		"--no-save",
		"--quiet",
		"--file=${file}"
	]
}

If you are using VS Code for R (on any platform) your comments would be especially most welcome. It’d be great to hear why you’re using it and how you’ve configured it to help make you as productive as RStudio or ESS has for others.