(defmacro with-entry
  "zip-output-stream に、エントリーを追加する"
  [[entry-name zip-output-stream] & body]
  `(try
     (.putNextEntry ^ZipOutputStream ~zip-output-stream
                    (ZipEntry. ^String ~entry-name))
     ~@body
     (finally (.closeEntry ~zip-output-stream))))

(defn make-archive [output-filename contents]
  (with-open [output (ZipOutputStream. (io/output-stream output-filename))]
    (doseq [{:keys [from to]} contents]
      (with-entry [to output]
        (with-open [in (io/input-stream from)]
          (io/copy in output))))))