From: Per Eckerdal per.eckerdal@gmail.com
Oh, the expand-source hooks must return an internal Gambit structure called source. It is used to mark s-expressions with source location information. See _eval.scm for details about it. I don't remember exactly how it works, but here's something that might help you get going:
Yes, I've seen ##surcify and the likes, but I wasn't sure it was the right way to go. Now I can try to understand them better.
Thank you very much.
--marco