Yes, at least in clojure and CL. In Clojure, you use nrepl. Emacs (and several other IDEs) have clients which open a socket connection to your running clojure p

Yes, at least in clojure and CL. In Clojure, you use nrepl. Emacs (and several other IDEs) have clients which open a socket connection to your running clojure process. While editing a function, emacs will say "tell me about `my.namespace/foo`". It then shows arity and argument name info for the fn. It's basically the same UX as you're used to in Java, except the info comes from asking the running process, rather than parsing statically.