let-map macro (creating a map using a let form) and map-let (using a map to establish local bindings in a let form)

let-map.clj

(defmacro let-map
  "Takes a binding form (as in let) and returns a map of (keywordized)
  binding names and bound values. It allows to construct a map sequentially.
  Usage:
  (let-map [a 1 b (+ a 1)])
  => {:a 1 :b 2}"
  [kv]
  (let [ks (map keyword (take-nth 2 kv))]
    `(let [~@kv]
       (into {} (map vec (partition 2 (interleave '~ks (take-nth 2 ~kv))))))))


(defmacro map-let
  [m body]
  "Takes a map literal and a body, evaluates body within a let form with local bindings 
  from each key of the map to its value (where binding names are un-keywordized).
  Usage:
  (map-let {:a 1 :b 2} [a b (+ a b)])
  => [1 2 3]"
  (let [ks (vec (map (comp symbol name) (keys m)))] 
    `(let [{:keys ~ks} ~m] ~body)))