FR: recursive tree-sitter injections

[edwloef]

Just noticed that there wasn't an open FR for this yet :P

A good way to test this is to see whether the code within a rust macro is syntax-highlighted, since the rust tree-sitter grammar injects rust into the macro contents.

[neurocyte]

We have injection support in the master branch. It was added about 2 months ago with the commit 634f453.

Do you have an example file you expect to look different?

[edwloef]

Ah, it seems to partially work, interesting. This bit of code, for example, doesn't get any syntax highlighting: https://codeberg.org/generic-daw/generic-daw/src/commit/df9a3b0d4cc9894332be3f93360993b130cffccd/generic_daw_gui/src/arrangement_view.rs#L1676-L1713. Maybe injections within injections aren't working correctly?

[neurocyte]

Maybe injections within injections aren't working correctly?

We limit injections to one level, yes. This is kind of intentional to avoid performance pot holes, but we could re-visit if there is an actual use case for fully recursive injections.

[edwloef]

I would think nesting declarative macros in Rust, like I've done there, isn't particularly rare (at least with the framework I'm using, that [primarily] uses declarative macros for row![], column![] and stack![]) 🤔 the deepest nesting in that project is I think 4 levels, but I can imagine that'd fluctuate.

[edwloef]

I've just learned that code snippets in rust doc comments are two levels (rust -> markdown -> rust), so that would be another use case