defwith -- sugar for try-finally macros

defwith.clj

(defmacro defwith [name finalizer]
  (let [bindings-sym (gensym "bindings")
        body-sym     (gensym "body")]
    `(defmacro ~name [~bindings-sym & ~body-sym]
       (cond
         (empty? ~bindings-sym) `(do ~@~body-sym)
         (symbol? (~bindings-sym 0))
         `(let ~(subvec ~bindings-sym 0 2)
            (try
              (~'~name ~(subvec ~bindings-sym 2) ~@~body-sym)
              (finally
               (~~finalizer ~(~bindings-sym 0)))))))))

(comment
;; for example:

(defwith with-delete
  (fn [x] (. x delete)))

(with-delete [tmp (java.io.File/createTempFile "tmp" nil)]
  (println "temporary file: " tmp))

)