Include syntax highlighting in vscode extension

[simonzkl]

Is your feature request related to a problem? Please describe.
The vscode extension right now only does LSP and relies on a third party vscode extension for syntax highlighting. The third party extension is out of date as well and doesn't support keywords introduced in 1.0.

Describe the solution you'd like
The syntax highlighting should be implemented in the official vscode extension.

Describe alternatives you've considered
I don't feel like having these separate makes sense from a user's perspective. Especially as the official lsp extension relies on the nickel language being registered. So the unofficial syntax highlighting extension is actually a hard requirement.

[yannham]

I'm not a VSCode user, so I don't know much about extension development, but that would be great if we could just piggy-back on tree-sitter, as we maintain a fairly up-to-date grammar already. It's hard to keep the number down (Vim, the Nickel parser, Prism.js for highlighting on the website, etc.), but the less grammars we have to maintain, the better 🙂

[szlend]

There's no vscode tree-sitter support yet, but they're discussing it. Until then I quickly hacked together a more complete and up to date vscode package:

https://marketplace.visualstudio.com/items?itemName=szlend.unofficial-vscode-nickel

[yannham]

Thanks @szlend, we're going to take a look, maybe re-use what you did as a base. I dream that one day we will only write one grammar specification, and derive a parser, various highlighters and plugins for editors, whatever is needed for a formatter, etc. but that day hasn't come yet 😞

[szlend]

Done in PR #1405

[yannham]

Syntax highlighting has been added and the extension is now available on the VSCode Market Place: https://marketplace.visualstudio.com/items?itemName=Tweag.vscode-nickel