- Online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript
- Regular Expressions Quick Start
- Regex Tutorial - POSIX Bracket Expressions can be relevant, for example in the implementation of pretokenizers e.g. by tiktoken
- Regex Tutorial - Unicode Characters and Properties
- Unicode character property - Wikipedia
Notes
- Regex is not globbing (and globbing is not regex) - globbing comes from libc (the C Standard Library) and is generally used for files in filesystems whereas regex is for matching patterns in text