Write a plugin in vimscript to be compatible with the original Vim

[jclsn]

This plugin exclusively written for Neovim, which can't be used in the original Vim. Many people still use it though. Would be great if there could also get one written in vim9script for Vim!

[holzensp]

That's a totally reasonable ask. It's going to be a while before we can prioritize this, though, so if you want it fast; PRs are most welcome ;) Ideally, though, we have one plugin that works in either, if that's doable.

[jclsn]

@holzensp Thank you for being open for this. It is doable, but currently it would have to be written in legacy vimscript. Although I am not sure if Neovim will add vim9script support in the future.

Ah seems there are plans

https://neovim.discourse.group/t/will-vim9-be-supported/2229/10

vim9script is also much nicer to program in, as it got rid of much of the quirks of legacy vimscript.

[holzensp]

In that case, I'd await the neovim support for vim9 before kicking this off.

[jclsn]

Upon further inquiry it seems they are not likely to support it any time soon.

neovim/neovim#13625

You could still write the plugin in legacy vimscript though, to make it available for both editors.

[jclsn]

Any news regarding this?

[bioball]

Hmm... I don't know how likely it is that we switch to vimscript. Much of what this plugin provides are integrations specific to neovim (specifically, the tree-sitter and LSP APIs). I don't think we're likely to write a syntax highlighter for Vim.

However, I definitely encourage you to try integrating vanilla Vim with pkl-lsp (maybe through vim-lsp)?

[jclsn]

@bioball Creating a vim syntax file is pretty straightforward. In fact I already started doing that here. Feel free to fork and improve things. I don't see myself going all the way here. I really don't understand the choice of creating a Neovim-only plugin. It just excludes a high number of users. Most plugin developers create a plugin usable by both.

I had a look at pkl-lsp, but was turned off by it being written in Java. I would probably use it though if I actually used pkl. Currently I am just interested in it. As long as the plugin is LSP-compliant, it should be possible via yeggapan/lsp or coc.nvim (yes, they really called it that. Most capable LSP client plugin out there though).

[jclsn]

@holzensp You could easily create a plugin usable for both. You could check for Neovim using

if has('nvim')
    source ./pkl-nvim.vim
else 
    source ./pkl-vim.vim
endif

to organize specific configurations.

[bioball]

That makes sense! I'd be fine with structuring this repo so that it's still usable for only vim users (where features like tree-sitter highlighting and LSP are disabled).

In fact I already started doing that here. Feel free to fork and improve things. I don't see myself going all the way here.

Very cool! Happy to accept PRs for this.

[jclsn]

Appreciate you are open for PRs! Let me see if I can help with the syntax file for starters! Can you maybe provide me with a .pkl reference file containing all keywords to test if the syntax works correctly? Or is there a list of all the keywords, so I don't have to hand-pick them all out of the documentation?

[bioball]

For implementing highlighting, the textmate grammar might be a good reference here: https://github.com/apple/pkl.tmbundle/blob/main/pkl/pkl.tmLanguage.pkl

This grammar is incomplete, but is good enough for the 90% case.

You can also take a look at the tree-sitter grammar, which is 99% complete (and also includes all of Pkl's keywords).

It should also be useful to inspect code in https://github.com/apple/pkl-pantry. For example, ModuleGenerator.pkl uses a lot of different types of nodes.

[jclsn]

So I made some progress. What are these annotations/decorators like `@SourceCode`? I could not find them in the documentation. In VSCode they don't seem to get highlighted either. I also highlighted the `# comments` inside verbatim strings as comments. This isn't done in VSCode either. Also nothing in the docs about those.