bounded-static VS competitive-programming-rs

I needed something similar a few years ago and went the Cow route and eventually pulled it into a crate: https://github.com/fujiapple852/bounded-static

Finished off and published the (very niche) bounded_static crate.

I have this question because, as practice, I'm trying to implement a struct Scanner based on this repo, and as an extra, I'd like to be able to handle errors instead of just panicking. However, unlike map(), the skip_while() and take_while() won't handle errors. If the Errs wouldn't happen unless in situations when the program were going very wrong, then I could just panic. Alternatively, is there a way to break and just return an error once bytes() gives an Err, with just iterator function chaining and without having to write loops myself?

This week I read about FnMut and FnOnce. I also found some amazing Rust code for parsing input/output for competitive programming , and solved all the google kickstart problems using it. I made two one hour video of my efforts starting here: https://youtu.be/EvL5YfPw8Ts