try++.clj

;; ALERT ALERT -- don't use this, it's busted code!

(defn catch-form? [form]
  (and (list? form)
       (= 'catch (first form))))

(defn transform-catch-form [catch-form]
  (if-not (sequential? (second catch-form))
    catch-form
    (let [[_catch [k v] e & catch-body] catch-form]
      `(catch Throwable ~e
         (when (= ~v (get (ex-data ~e) ~k))
           ~@catch-body)))))

(defmacro try++ [& args]
  (let [body (remove catch-form? args)
        catch-forms (filter catch-form? args)]
    `(try
       ~@body
       ~@(map transform-catch-form catch-forms))))

;; example:
(try++
 (throw (ex-info "asdasd" {:status 400}))
 (throw (Exception. "Boom"))
 (catch [:status 400] e2
   (println (ex-data e2)))
 (catch Exception e1
   (println (.getMessage e1))))