Routing by URL postfix

Is it possible to separate the parts of a routing with a character
other than ‘/’? Specifically, I’d like to be able to do something
like:

map.connect ‘:controller/:action.:format’

which would match

“blog/index.html” as {:controller => “blog”, :action => “index”,
:format => “html”}

and

“blog/index.atom” as {:controller => “blog”, :action => “index”,
:format => “atom”}

Currently, I use:

map.connect ‘:controller/*path’

and do some of the routing logic in the controller, which is doable
but not very clean. Before I wander off and write a patch, has anyone
done this already?

Regards,

Simon