Do we actually need the mzscheme dependency? Any reason we couldn't switch to a full racket base?
Interesting. I'll have to play around with that. And study it a bit more to figure out how it works. If I understand your description correctly, the reason you're using lists is so that 'nil is interpreted as no value, while '(nil) is interpreted as intentionally passing the value 'nil? How does the function know the difference?
Interesting opinion. Unless I misunderstood you, I would have felt the opposite way. Normally, I would expect the purpose of the data interaction layer to be separating the implementation details from the code, so that if changes need to be made to what backend storage system you can just trade it out.
Maybe that is what you mean though, and that's supposed to be a distinction between the "driver" and an additional abstraction layer. Though your comment about ORMs including sugar confuses that a bit. I don't really want sugar per se, just abstraction away from how I'm actually storing the data, within reason anyway.
When I was using Arc heavily, I defined a utility (sobj ...) that was just like (obj ...) but it wrapped everything in a singleton list. That may have been the only extra utility I needed.
I could write (each (k (v)) tab ...) in place of (each (k v) tab ...). I could write tab!key.0 in place of tab!key. I could write (iflet (v) tab!key ...) in place of (iflet v tab!key ...).
It was surprisingly unintrusive, even pleasant.
"Normally, I would expect the purpose of the data interaction layer to be separating the implementation details from the code, so that if changes need to be made to what backend storage system you can just trade it out."
I like the sound of that, but I think it's always a bit leaky, unless the result is a full database design that lets people happily forget there's another database underneath.