Create map from alternating series of keys and values

map-pairs.clj

(defn make-pairs
  "Creates a vector of pairs from the incoming sequence. Ignores extra elements."
  ([] []) ; return an empty vector if supplied no arguments
  ([seq] (make-pairs seq [])); return a vector of pairs taken from seq
  ([seq pairs] ; return a vector of pairs, starting with some existing pairs
  (if (< (count seq) 2) pairs
      (make-pairs (rest (rest seq))
                  (conj (vec pairs) [(first seq) (second seq)])))))

(defn map-pairs
  "Creates a map from pairs of values from seq. Ignores extra elements."
  [seq]
  (into {} (make-pairs seq)))