[Dev-luatex] string library with utf-8 support

[Olivier Binda]

Hello, I developped a Japanese dictionnary in XeTeX.
It compiles just fine in luatex but I would like to code the commands in 
Lua instead of TeX.
To make the code faster, cleaner, simpler and more powerfull.

Yet, I need to be able to manipulate utf-8 strings (find, substring, 
replace, length, etc...).
Is there a simple way to do that in LUA ? Will there be one day a luatex 
library for utf8 string managments ?
(because it seems the string library is just for strings with 1 byte 
characters and it is really lacking)

Keep up the good work.
Olivier Binda