I've used this approach before. It was simple and worked well. Note that assoc can take multiple keys and vals so you can simplify it to (assoc m k v v k) instead of nesting the assoc calls. If there's any chance of a collision, you could be defensive and test for (contains? m k) or (contains? m v) and take appropriate action (maybe throw). It might be a good thing to put into a pre-condition.
On May 25, 2011, at 11:12 PM, Ken Wesson wrote: > If the token and id sets are disjoint (no single object can ever > appear as each -- only one of those at most) then you can use a single > map with a function put defined as: > > (defn put [m k v] > (assoc (assoc m k v) v k)) > > which adds mappings in both directions. Then just use (m k) or (m v) > to perform lookups in either direction. The overhead may be less than > with two separate hashmaps, and the code is certainly simpler. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
