General discussion about support for other languages than just Python

[clouds56]

Is it possible to make jupyter support other language like julia and R?
Or at least provide some interface for other extension to integrate.

[rchiodo]

@clouds56, at the moment no.

[rchiodo]

This would be a good spot to have people vote on other languages. Which ones do you want besides python?

[rchiodo]

Julia?

[rchiodo]

R?

[rchiodo]

Haskell?

[rchiodo]

C#/F#?

[rchiodo]

Scala?

[raghavgautam]

Bash ?

[chrishales709]

SAS?

[dr-br]

cling?

[stevengj]

I don't see any point in voting on languages here — supporting two languages should be the same amount of work as supporting all languages. The whole point of Jupyter is that it defines a language-independent protocol … if there is a general vscode extension for notebooks, it should work with any notebook in any language (i.e. it should be decoupled from vscode-python, analogous to nteract/hydrogen).

That is, when you open a Jupyter notebook file (.ipynb), the kernelspec.name metadata should tell you the name foo of the kernel to run. You then look for a kernelspec file foo/kernel.json in the standard locations. This file looks something like

{
  "display_name": "Julia 1.2.0",
  "argv": [
    "/Applications/Julia-1.2.app/Contents/Resources/julia/bin/julia",
    "-i",
    "--startup-file=yes",
    "--color=yes",
    "--project=@.",
    "/Users/me/.julia/packages/IJulia/src/kernel.jl",
    "{connection_file}"
  ],
  "language": "julia",
  "env": {},
  "interrupt_mode": "signal"
}

and tells you exactly how to launch the kernel (via the argv). You create a connection file, pass this for the {connection_file} argument when starting the kernel, and then talk to the kernel over ZMQ in exactly the same way that you talk to the Python kernel.

[rchiodo]

Unfortunately supporting a kernel is not the same as supporting a language. We run a bunch of stuff that is specific to python in order to get things like theming, variables, startup directories, etc correct. None of those work without figuring out a language neutral or per language way to do them.

We will be supporting other kernels long before we support other languages. This item here:
https://github.com/microsoft/vscode-python/issues/3123
has the beginnings of how this will work.

@hochshi has implemented picking a kernel in remote situations here (which will hopefully go in soon)
microsoft/vscode-python#7790

[al6x]

Supporting just the the script itself, as an interactive notebook, without the Jupyther dependency would be even better.

[rchiodo]

Supporting just the the script itself, as an interactive notebook, without the Jupyther dependency would be even better.

@alexeyPetrushin can you elaborate more? Jupyter is just a framework for hosting a process that's running your code. I don't think we'd reinvent this ourselves. Is there something you don't like about having jupyter installed?

[stevengj]

You don't need a dependency on the Jupyter software stack if you simply speak the Jupyter messaging protocol to the kernel. e.g. nteract does this.

(You obviously need the software installed for any kernel you want to use, e.g. you need the ipython kernel installed if you want to talk to Python, which pulls in components from Jupyter. But you wouldn't need e.g. the jupyterlab component. And other languages might not need Jupyter software at all. For example, the Jupyter kernel for Julia has no dependency on the Jupyter software stack — it simply speaks the Jupyter protocol over ZMQ to anything that launches it.)

Unfortunately supporting a kernel is not the same as supporting a language. We run a bunch of stuff that is specific to python in order to get things like theming, variables, startup directories, etc correct. None of those work without figuring out a language neutral or per language way to do them.

By "theming" I guess you mean syntax highlighting etcetera? Why can't you simply read the language field of the kernelspec file and activate the syntax mode for the corresponding language?

Not sure what you mean by "startup directories" … the kernelspec file also tells you exactly how to launch a kernel, including any relevant environment variables.

I'm not speaking theoretically — JupyterLab and nteract do this in a language-neutral way already.