Render route containing dash

[dboris]

To demonstrate the issue:

(defroute good "/:a:b/:c" [])
(good {:a 1 :b 2 :c 3}) => "/12/3"

(defroute bad "/:a-:b/:c" [])
(bad {:a 1 :b 2 :c 3}) => "/:a-2/3"

Is there any way to render "bad" as "/1-2/3"?