Paren issues with Clojure probably mean your functions are too long? I like to keep mine down to 8-10 lines or less when possible, keep them flat and composable, use threading macro and then transducers for performance. At least that's how I read it. AST might not matter much either way, or in a stranger way, because the LLM's corpus and progression through code will give it a kind of shadow or grooves of an ast, but it isn't making or receiving any ast from this piece of code.

Still, Elixir scores best on the TenCent AutoCodebench, by far actually, "despite" being like Clojure built with an AST and immutability. Clojure wasn't part of those tests but I use both daily with LLMs (mostly Codex) and imagine it's on par with Elixir. The repl is better than Elixir's. Both have serious strengths.