connection.clj

(def connection {:host "127.0.0.1"})

(defn query [conn query]
  (str (:host conn) ":" query))

(defn query-with-modifiers [conn query modifiers]
  (str (:host conn) ":" query ":" modifiers))

(defmacro with-connection
  [conn & body]
  `(map (fn [op#]
          (let [call# (resolve (first op#))
                args# (rest op#)]
            (apply (partial call# ~conn) args#)))
        (quote ~body)))

(with-connection connection
  (query "q1")
  (query "q2")
  (query "q3")
  (query-with-modifiers "q4" "my-modifiers"))