[a-z] means a to z
x* means 0 or more xs
...
The problem is that
a) whitespace is significant, so long regexes start to become unreadable
b) no easy way to nest regexes
Perl 6/Raku seemed to solve this by making whitespace meaningless by default and allowing regexes to be nested into other regexes or entire "grammars".
- use only those regex features that are cross-platform (cross-engine?)
- avoid `\w` and similar (what is word?) and instead use explicit rules (`[a-zA-Z]+`)
- use [] instead of backslashes when escaping (`[(]` instead of `\(`) - especially useful with double/triple escaping
- never use long regexes (there is always a better way)
I never understood why people are afraid of regular expressions.
That said, there are some performance/security implications wrt. backtracking that one should be aware of [0].
[0] https://javascript.info/regexp-catastrophic-backtracking
I don't think that's a good idea. What about Chinese, Japanese, Arabic, ...?