Embedded Syntax Highlighting in Neovim with Nix Multiline Strings

collinarnett · February 26, 2023, 1:00pm

GitHub flavored markdown has a neat feature where you can specify what language you want highlighted in a code block:

```nix

I was wondering, how to set this up with nix files and multiline strings in Neovim. Something like:

''lua

Bonus if the block can also leverage LSP support for the given language.

There were a couple of suggestions here:
https://www.reddit.com/r/NixOS/comments/ymdgm9/how_can_i_get_vim_syntax_highlighting_within_a/

Some of the suggestions were:

Use treesitter (idk what this means)
FeMaco (not in nixpkgs)
A PR to vim-nix

My problem stems from the fact that I would like to use nix paths in my lua configs and so referencing them externally is not possible.

Here’s my config if you want to see an example:

github.com

collinarnett/brew/blob/acccf06a880486f06dde2c03391c80875c3c9328/modules/home-manager/neovim/neovim.nix

{pkgs, ...}: {
  programs.neovim = {
    enable = true;
    defaultEditor = true;
    vimAlias = true;
    plugins = with pkgs.vimPlugins; [
      neo-tree-nvim # File-browser
      vimwiki # Wiki
      {
        plugin = lualine-nvim;
        type = "lua";
        config = ''
          local function metals_status()
            return vim.g["metals_status"] or ""
          end
          require('lualine').setup(
            {
              options = { theme = 'dracula-nvim' },
              sections = {
                lualine_a = { 'mode' },

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Relevant discussion:

rnhmjoj · February 26, 2023, 5:03pm

What you’re looking for is called “language injection”.
For neovim you can install the nvim-treesitter plugin with the Nix parser (and more parsers for the language you wish to highlight). If you use the unstable channel nvim-treesitter should have some of these injections by default: for example it should highlight writeScript and buildPhase as bash, etc.

collinarnett · February 26, 2023, 5:15pm

I’m currently using plugin = nvim-treesitter.withAllGrammars; # Syntax Highlighting in my config and I am also on unstable. Is there something else that I need to add? I also tried adding /* lua */ in front of my multiline strings but that didn’t work either.

figsoda · February 26, 2023, 5:17pm

/* language */ nix injections are not implemented in nvim-treesitter yet. It was previously not possible without adding directives, so I opened feat(treesitter): allow capture text to be transformed by figsoda · Pull Request #21548 · neovim/neovim · GitHub, and I’ll implement the nvim-treesitter part once that 0.9.0 is stable.

figsoda · April 15, 2023, 6:04pm

An update on the issue, opened injections(nix): dynamic language injection via comments by figsoda · Pull Request #4658 · nvim-treesitter/nvim-treesitter · GitHub to implement the feature upstream, and neovim-unwrapped: apply patch to fix the `#gsub!` directive by figsoda · Pull Request #226323 · NixOS/nixpkgs · GitHub to backport a required bugfix to nixpkgs

svrana · April 4, 2024, 7:17pm

I’ve got the embedded lua treesitter highlighting working for lua plugins via home-manager here nix-home/home/config/nvim/queries/nix/injections.scm at 242bf7485cf64ae3579564c90d916f13078a6eda · svrana/nix-home · GitHub

That file should be placed in .config/nvim/queries/nix/injections.scm. I have hm put it in place for me.

symphorien · April 9, 2024, 8:34pm

It works without any configuration for me, and the syntax highlighting defaults to bash when the corresponding attribute name is somethingPhase or postSomething: