Hi all, Getting bored of hacking fonts, and inspired by a discussion on XeTeX list, I wrote a small lua module that tries to handle the various space characters defined in Unicode and convert them to something TeX understands.
The code is here: https://github.com/khaledhosny/luaunicodespace It reads the node list and converts the space characters to glue nodes and penalty nodes if necessary. It is just a proof of concept, and need to be extended a bit to be more useful, if there is an interest in it. Regards, Khaled
