specialize type and default

(defgeneric range->cannon (range &key jump-friendly-p jump-enemy-p before-spaces after-spaces capture-screen-p screen-count)
  (:documentation "Changes a range to a cannon by adding the requisite data."))
(defmethod range->cannon ((range range) &key
              (jump-friendly-p  t)
              (jump-enemy-p     t)
              (before-spaces    :any)
              (after-spaces     :any)
              (capture-screen-p nil)
              (screen-count     1))
  ; meh
)