> Looking closer, GNU grep, git grep, ripgrep all support PCRE. That might be an okay alternative. It would take some time and effort to switch over. I do not know yet whether it would be worth the effort, but getting used to a different syntax that's used by a wide number of tools seems more useful than getting used to a different syntax that's used by a single tool, no matter how useful the tool.

Yes, that's true. You could do that.

I will say though that if you take PCRE, EREs and ripgrep's default regex engine, they all support largely the same syntax. There are differences of course (you've pointed out one already), but they're a lot more alike than they are different.

BREs are the oddball with its escaping rules. But if you know the escaping rules they can be quite useful in a context where most of what you're searching for is a literal with some regex aspects. Vim's default regex syntax is like this for example and it is quite useful in that context.

And yes, grep's tend to have a lot of extensions. So I guess what you're after is "GNU's particular extension of regex syntax." Idk, just seems like if that's what you care most about, then just keep using GNU tooling. Otherwise, ripgrep's default regex engine is very very similar to EREs and other Perl inspired regex syntaxes. Which is intentional.

The \< and \> stuff might be something I implement eventually, but I've always found them strange. YMMV.