True, it does not support UTF-8, just as the original Lua patterns do not. I guess having proper support for UTF-8 would probably include supporting Unicode as well and would complicate things a lot- for example, matching any unicode upper case character with %u would not be trivial.
BTW: YEs, I've seen nim-regex, which is also very nice. The lua pattern port is mainly for my personal use, because I'm leaving Lua more then 10 years of Lua behind, but I dearly miss the patterns. The advantage is that they are much more simple then regular expressions, which often result in something that I can read and understand a year after I wrote it - which is often not the case with full fledged PCRE regular expressions. (Personally, I'd prefer pure Nim regex handing in the Nim stdlib over a PCRE based solution which requires external libs, would nim-regex not be a nice candidate?)
