fancy-regex VS BSDCoreUtils

https://github.com/fancy-regex/fancy-regex/issues/84 it's still open issue

Ahh, very interesting, thanks for sharing! Do you have any thoughts around why that is? I presume that's due to Oniguruma supporting a much broader feature set and something like fancy-regexp's approach with mixing a backtracking VM and NFA implementation for simple queries would be needed for better perf? (I am aware you played a role in that) [1]

I have been playing around with regex parsing through building parsers through parser combinators at runtime recently, no clue how it will perform in practice yet (structuring parser generators at runtime is challenging in general in low-level languages) but maybe that could pan out and lead to an interesting way to support broader sets of regex syntaxes like POSIX in a relatively straightforward and performant way.

[1] https://github.com/fancy-regex/fancy-regex#theory

Not an expert but fancy regex is a Rust library that uses a hybrid approach to detect whether a sub expression contains backtracking and delegates to the appropriate engine.

https://github.com/fancy-regex/fancy-regex

https://github.com/DiegoMagdaleno/BSDCoreUtils/blob/master/src/cat/cat.c (not upstream but a port)

The Rust implementation that we are discussing is MIT licensed and as far as I know not part of GNU.

I do not believe that "Coreutils" is trademarked by GNU.

There are other projects that use the name "Coreutils" that are not part of GNU:

https://github.com/DiegoMagdaleno/BSDCoreUtils

Unsure. Would BSD CoreUtils help?

This makes me want to build a container for testing scripts that contains: posh, BSD coretools, shellcheck, checkbashisms.