Token filters are an experimental add-on to Lua 5. They've been discussed extensively on the list, and there are a couple alternative implementations currently.
In short, they will allow one to "cut in" the token stream, modifying syntactical things as long as the outcoming stream remains valid Lua tokens. In the exhibited case, one would simply add "nil" where two consequtive commas occur. In practise, it is not quite as simple as this.
Alternatives to experiment with include lhf's token filter patch, my fsyntax.lua/ftools.lua which builds upon it (adding syntax awareness), and MetaLua (which in my opinion has way too complex expressions, but I'm biased... ;)
RJP Computing kirjoitti 22.7.2007 kello 20:55:
On 7/22/07, Asko Kauppi <email@example.com> wrote: