* Exclude hex above max Unicode Scalar Value
simplify surrogate regex to use ranges
* allow leading 0s, but still limit max length to 6
* Add explicit regex-set rules to hex unicode
document {1,3} ranges
* add space-separators between sets
* Make test fail *only* for length limits
Previously it failed due to specifying a codepoint past max *as well*, obscuring the intended fail condition.
---------
Co-authored-by: Tab Atkins Jr. <jackalmage@gmail.com>
Evgeny