> if the key is missing today you'll get nil as the value You can add a third parameter to override the nil if detecting the missing key matters. (You almost

> if the key is missing today you'll get nil as the value You can add a third parameter to override the nil if detecting the missing key matters. (You almost surely know this, but not all HN commenters will.) user> (:bar {:foo 1}) nil user> (:bar {:foo 1} :missing) :missing