This is just going to be random. Don't expect it to make sense.
The obvious next steps in my Scheme are: Strings. A Common Lisp 22.1.1 compliant hand-written parser, as a prologue to re-writing it in Scheme, where the record objects used in Coglan's version are replaced with cons list of the various fields being collected.
Macros. And that's where my brain comes a screeching halt. Because "macros" seem to imply a certain purity of lispyness. How do I make a Lisp macro engine that successfully handles, and yet successfully ignores, all of the extra stuff after the content?
Maybe I _don't. _Maybe I just write it so that it accepts all that, and more, because ultimately I want to add a deterministic more to the list to carry typing information.
Grief, I have no idea at this point. I just know what I want it to be able to do next.