Iteration

(deftype Iteration [xform coll]
   ISequential
   
   ISeqable
   (-seq [_] (seq (sequence xform coll)))

   IReduce
   (-reduce [_ f init] (transduce xform f init coll))

   IPrintWithWriter
   (-pr-writer [coll writer opts]
     (pr-sequential-writer writer pr-writer "(" " " ")" opts coll)))