(defn do-map
  "Returns a vector of applying f to all first elements of the given collections, all second elements and so on
   until any one of the collections is exhausted.
  "
  ([f coll]
    (loop [s (seq coll), result (transient [])]
      (let [e (first s)]
        (if e
          (recur (rest s), (conj! result (f e)))
          (persistent! result)
        )
      )
    )
  )
  ([f c1 c2]
    (loop [s1 (seq c1), s2 (seq c2), result (transient [])]
      (let [e1 (first s1), e2 (first s2)]
        (if (and e1 e2)
          (recur (rest s1), (rest s2), (conj! result (f e1, e2)) )
          (persistent! result)
        )
      )
    )
  )
  ([f c1 c2 c3]
    (loop [s1 (seq c1), s2 (seq c2), s3 (seq c3), result (transient [])]
      (let [e1 (first s1), e2 (first s2), e3 (first s3)]
        (if (and e1 e2 e3)
          (recur (rest s1), (rest s2), (rest s3), (conj! result (f e1, e2, e3)) )
          (persistent! result)
        )
      )
    )
  )
  ([f c1 c2 c3 & colls]
    (let [colls (conj colls c3 c2 c1)]
      (loop [seqs (do-map seq colls), result (transient [])]
        (let [es (do-map first seqs)]
          (if (every? identity es)
            (recur (do-map rest seqs), (conj! result (apply f es)))
            (persistent! result)
          )
        )
      )
    )
  )
)