If Clojure data structures are being round-tripped, clj-msgpack converts keywords into strings. An optional mechanism to force interpretation of strings which look like keywords as such would be a useful convenience feature.

This has obvious corruption potential, and should require user intervention to enable.

(def ^:dynamic *keywordize-strings*
  "Assume that any string starting with a colon should be unpacked to a keyword"
  false)
(extend-protocol Unwrapable
  RawValue
  (unwrap [o]
    (let [v (.getString o)]
      (if (and *keywordize-strings* (.startsWith v ":"))
        (keyword (.substring v 1))
        v))))

user> (pack (make-array Short/TYPE 4))

<byte[] [B@68b668b6>

user> (pack (make-array Short 4))
; Evaluation aborted.