Steven Levithan

Yeah, there are many esoteric Oniguruma features and sub-features that are rarely used (or not used at all) in popular TM grammars (I'm primarily looking at grammars provided by [Shiki](https://shiki.style/))....

If @ota-meshi thinks this is a good idea, I'd be all for it. And I'd be happy to help, at least with answering any questions and making changes to Regex+...

I'm also not able to work on this for similar reasons. But maybe there's an opportunity to do something much simpler? If `eslint-plugin-regexp` could run on the `.toString()` (or `.source`...

I didn't mention anything about that. Nor does this project's readme. Aside: I don't think +N or -N relative offsets for backreferences or subroutines are needed or desirable.

This is an interesting use case. Given that the data cached for each regex is small, I'm assuming that for it to be an issue, XRegExp has to be used...

A feature flag to disable caching is a great idea. However, although I'm very open to PRs, I probably won't build this myself since XRegExp is now mostly in maintenance...

You've offered multiple good suggestions, and the project maintainer/owner can better speak to what they'd prefer to see. But note that there's an existing system for patching grammars at build-time....

Closed since the PR was merged months ago. Assuming this is complete.

So, I think this project by @RedCMD is wonderful, a labor of love by a master at his craft, and that every TextMate grammar author should be aware of it....

> `Error: Invalid group` isn't all too helpful I can improve the "invalid group" error. But yeah, you'll currently get that if the character following `(?` isn't a supported group...