funny_sorted_set_by.clj

; sorting seqables by length, but keep same-length seqables based on (in)equality
user=> (def comparator (reify java.util.Comparator
                  (compare [this x y]
                    (let [v (compare (count x) (count y))]
                      (if (and (zero? v) (not= x y))
                        -1
                        v)))))
#'user/comparator
user=> (sorted-set-by comparator "foo" "bar" "a" "b" "bar" "futz")
#{"b"
  "a"
  "bar"
  "foo" "futz"}