You know, I tried clojure out, but the cons cells are implemented in a weird way; they can't combine two objects, only an object and a sequence. So I could probably do something like trellises, but they wouldn't be as elegant.

I think one can use [a b] and destructuring instead of cons/car/cdr and be as elegant.

As I understand it, the finger trees library for clojure would give you more flexibility and better performance.

https://github.com/clojure/data.finger-tree