With some extra work I did manage too squeeze everything into 256 characters. The worst case is the following expression that weighs in at 190+.
Mar 24 2016
Mar 23 2016
It is the first string that contains more than 256 characters. The expression is put in an ordinary string before assigning it to the driver, in order to generate a better error message.
Jan 12 2014
I uploaded a very rough Autocad importer to rapidshare four years ago, It was very incomplete and never had any official status, and I have forgotten everything about it. If anybody has made any official release it must be migius, whose has spent quite a while on his importer.. He can be found on blenderartists.