Lua 5.3 can iterate over a UTF-8 string. You can even index character positions ...

spc476 on Oct 13, 2016 | parent | context | favorite | on: Why Unicode Won’t Work on the Internet (2001)

Lua 5.3 can iterate over a UTF-8 string. You can even index character positions (not byte positions) in a UTF-8 string. Some more information here: https://www.lua.org/manual/5.3/manual.html#6.5

Edit: fixed link