Character class negation is undocumented

[mdinger]

Character class negation isn't documented anywhere in regex. I asked on IRC where they told be the syntax is <-[abcd]> compared with Perl5 [^abcd].

This should be documented.

[pmichaud]

It's kind of documented, but not as clearly as it ought to be. The text currently reads:

In between the < > , you can also use the same operators for categories (+, |, &, -, ^) to combine multiple range definitions and even mix in some of the unicode categories above. Another thing you are allowed to write between the [ ] is the backslashed forms for character classes.

The + and - "operators" it refers to are the ones that handling character class addition and negation. I agree it's unclear as written, and there ought to be an example showing the most common negation form.

[mdinger]

Awesome! I'd also expand on how operators behave when on the endpoints they are usually binary operators and it might not be immediately apparent how they might operate as lone prefixes/suffixes (although, now that I think about it, I can see how they might operate).