Is anyone actively working on fixing 323/adding support for the other new features? I didn't see any active PRs related to it, and no one had commented on the issue, but I figured I'd ask first.

Is anyone actively working on fixing 323/adding support for the other new features?

Not that I know of, no. Iirc I wrote a comment asking for advice on how the API might look like, but had no responses. I did have a quick look at implementing support for popping multiple contexts at once but it wasn't trivial with the current design.

Oh, see the minimum supported rust version CI error, you just need to borrow the array you're iterating.

CI error should be fixed with the latest push.

As for backtracking, thanks for bringing that up. I'd only seen issue 323 and not issue 271, so I hadn't realized that was another potential pain point before bumping to ST4. It looks like a bunch of grammars are already using the backtracking-related features:

Batch File/Batch File.sublime-syntax
C#/C#.sublime-syntax
Git Formats/Git Commit.sublime-syntax
Java/Java.sublime-syntax
JavaScript/JSX.sublime-syntax
JavaScript/JavaScript.sublime-syntax
JavaScript/TSX.sublime-syntax
JavaScript/TypeScript.sublime-syntax
Lua/Lua.sublime-syntax
Markdown/Markdown.sublime-syntax
PHP/PHP Source.sublime-syntax
Python/Python.sublime-syntax
SQL/SQL.sublime-syntax

Apart from backtracking, it sounds like adding support for the 4075-specific features, such as syntax inheritance, is not as complicated and shouldn't affect the public API -- is that a fair assessment?

... grammars which are using branch: ...

also add these pending re-writes from PRs:

• Haskell
• JSON

Could someone please kick-off the PR testing again? The clippy issue should be fixed, and I'm seeing a "First-time contributors need a maintainer to approve running workflows" message.

Huh I tried re-running it and the clippy issue happened again. Did you already look into it? Looks like the problem is that the time crate updated past our MSRV, which of course isn't a problem with this PR. Perhaps we need to either bump our MSRV or constrain an older version of the time crate.

I created a PR to bump MSRV along with a motivation of why I believe that is preferred over putting an upper limit on time: #422

Thanks @Enselic, we can retest and land this PR after your PR lands.

@varungandhi-src Could you merge origin/master into this branch so CI becomes green please?

@Enselic rebased and force-pushed; sorry I hadn't realized that PR testing was running pre-merge instead of after locally merging into master.

Since this has been Approved by both Tristan and Keith I will merge this now that CI is green. I took a quick look and the code looked good to me too.

I will add an entry for this PR to CHANGELOG at a later point as part of #409