UTF8

Provides UTF-8 aware string functions implemented in pure lua:

• string.utf8len(s)
• string.utf8sub(s, i, j)
• string.utf8reverse(s)

If utf8data.lua (containing the lower<->upper case mappings) is loaded, these additional functions are available:

• string.utf8upper(s)
• string.utf8lower(s)

All functions behave as their non UTF-8 aware counterparts with the exception that UTF-8 characters are used instead of bytes for all units.