TIL predicate dispatch. https://en.wikipedia.org/wiki/Predicate_dispatch learned thanks to "smart #Clojure people"® a la https://clojureverse.org/t/dispacio-predicate-dispatch-for-clojure-script/8956 . One of those things I never knew I never knew I never knew. Suppose you want to dispatch based on some 3rd-party or other dynamic value.