Is there any Lua library that converts a string to bytes using UTF8 encoding?

Question

I wonder whether this kind of library exists.

Answer 1

Lua 5.3 has UTF-8 support in the standard library now.

For example, to get a UTF-8 string's code points:

for p, c in utf8.codes("瑞&于") do
  print(c)
end

Output:

29790
38
20110