gistfile1.txt

(defmacro with-var-roots [bindings & body]
  (let [settings (partition 2 bindings)
        tmpvars (repeatedly (count settings) (partial gensym "old"))
        vars (map first settings)
        savevals (vec (mapcat (fn [t v] [t v]) tmpvars vars))
        setters (for [[v s] settings] `(set-var-root ~v ~s))
        restorers (map (fn [v s] `(set-var-root ~v ~s)) vars tmpvars)
        ]
    `(let ~savevals
      ~@setters
      (try
        ~@body
      (finally
        ~@restorers))
      )))