capture class bytes

scratch.clj

(def classbytes (atom {}))

(defn bytes-of-forms [form]
  (push-thread-bindings
   {clojure.lang.Compiler/LOADER
    (proxy [clojure.lang.DynamicClassLoader] [@clojure.lang.Compiler/LOADER]
      (defineClass
        ([name bytes src]
           (swap! classbytes assoc name bytes)
           (proxy-super defineClass name bytes src))))})
  (try
    (let [line @clojure.lang.Compiler/LINE
          column @clojure.lang.Compiler/COLUMN
          line (if-let [line (:line (meta form))]
                 line
                 line)
          column (if-let [column (:column (meta form))]
                   column
                   column)]
      (push-thread-bindings {clojure.lang.Compiler/LINE line
                             clojure.lang.Compiler/COLUMN column})
      (try
        (let [form (macroexpand form)]
          (cond
           (and (seq? form) (= 'do (first form)))
           (do
             (doseq [f (butlast (rest form))]
               (bytes-of-forms f))
             (bytes-of-forms (last form)))
           (and (or (instance? clojure.lang.IType form)
                    (coll? form))
                (not (and (symbol? (first form))
                          (.startsWith (name (first form)) "def"))))
           (let [exp (clojure.lang.Compiler/analyze
                      clojure.lang.Compiler$C/EXPRESSION
                      `(fn [] ~form))]
             ((.eval exp)))
           :else (let [exp (clojure.lang.Compiler/analyze
                            clojure.lang.Compiler$C/EVAL
                            form)]
                   (.eval exp))))
        (finally
          (pop-thread-bindings))))
    (finally
      (pop-thread-bindings))))