ClojureScript watchers and validators

Thanks to some nice work by Bobby Calderwood ClojureScript now has Atom validators and watchers. Some commentary below: Setting a validator Placing a validator on an Atom is as easy as: (def A (atom 0 (fn [key a old-val new-val] (== 0 new-val)))) @A ;=> 0 (swap! A inc) ;; AssertionError @A ;=> 0 As [...]