Add TextMate Grammar for Linden Scripting Language (LSL)

[bennettgoble]

We’re looking for a high-quality TextMate grammar for Linden Scripting Language (LSL) to be added to this repository so that it can ultimately be be contributed to tm-grammars, the canonical grammar collection used by Shiki.

Why This Matters

We are looking to use Mintlify for documentation, which relies on Shiki for syntax highlighting. LSL code blocks are currently unhighlighted, making developer docs harder to read and write. Fixing this will benefit the Second Life scripting community and enhance the developer experience across the web wherever Shiki is used.

Acceptance Criteria

• Create a fully functional .tmLanguage.json grammar for LSL and make a PR against this repository
• Proper classification of LSL keywords, types, constants, events, functions, and operators
• Verified syntax highlighting using the Shiki engine (e.g., via shiki-playground)
• LSL added to the languages.json mapping if necessary
• Demo screenshot or GIF showing LSL highlighting in action

Further details

• Make this grammar as evergreen as possible, we don't want to have to update it every time a new library function is added
  • Ex. target patterns (functions begin with ll...(), constants are all caps snake case, etc.) instead of targeting a finite list of key words

[Martin-Pitt]

I was struggling with this problem in my project earlier since Astro uses Expressive Code which has Shiki under the hood for its syntax highlighting.

The solution was to convert the existing language grammar work that GitHub itself uses through textmate/secondlife-lsl.tmbundle and then convert that into a JSON version for Shiki lsl_grammar.json and automate updating autogenerate-grammar.js in my repo (triggered from a GitHub Action workflow that copies the definitions yaml).

Wasn't confident enough to submit to Shiki myself as wasn't 100% sure I had converted to JSON properly, was just happy it was working enough for some small example scripts for now. I also only did a basic trie based optimisation for the regexes, so they aren't as nice as the optimised regexes by the secondlife-lsl.tmbundle authors.

Note here that there are two popular syntax highlighters: Linguist (via secondlife-lsl.tmbundle) and Shiki.
So both GitHub itself and the Shiki ecosystem should be kept up to date.

Side note: The reason you don't want to make an evergreen ll* syntax highlighter is that it gives scripters the impression that a typo'd function is actually valid. Sure it's a bit more work in the grammar syntax, having to keep it up to date is a PITA, but it is something that can be automated now and should really be.

[RedCMD]

here's my VSCode extension to help with authoring TextMate grammars https://marketplace.visualstudio.com/items?itemName=RedCMD.tmlanguage-syntax-highlighter