Representing [Clojure] code in JSON

gistfile1.clj

; Context:
; http://stackoverflow.com/questions/3436216/how-to-map-clojure-code-to-and-from-json

(defn escape-string [x]
  (clojure.string/replace x #"^[':\\]" "\\\\$0"))

(defn code-to-json [x]
  (condp #(%1 %2) x
    number?  x
    symbol?  (str \' (name x))
    keyword? (str \: (name x))
    string?  (escape-string x)
    list?    (into [] (cons "list"   (map code-to-json x)))
    vector?  (into [] (cons "vector" (map code-to-json x)))
    set?     (into [] (cons "set"    (map code-to-json x)))
    map?     (into {} (map #(mapv code-to-json %) x))
    (throw (Exception. (format "Unsupported type: %s" (type x))))))