macro.clj

(defmacro defthreader [macro-name & rest]
  (let [[macro-name [check-func]] (name-with-attributes macro-name rest)]
    `(defmacro ~macro-name
     ([argvec#] (~macro-name argvec# identity))
     ([argvec# subphase# & left#]
        `(fn [~'session# ~@argvec#]
           (--> ~'session#
                ~subphase#
                (~~check-func (str "The threaded argument passed out of " '~subphase#))
                ~@(when left#
                    [`((~'macro-name ~argvec# ~@left#) ~@argvec#)])))))))