Clojure if-let accepting multiple bindings

if_let_multi.clj

(ns if-let-multi-bind.core)

(defmacro if-let*
  ([bindings then]
     `(if-let* ~bindings ~then nil))
  ([bindings then else & oldform]
     (let [test (cons #'and (map last (partition 2 bindings)))]
       `(if ~test
          (let ~bindings
            ~then)
          ~else))))

(comment
  (if-let* [a 1
            b 3]
           (+ a b))
  ;; 4

  (if-let* [a 1
            b nil]
           (+ a b))
  ;; nil

  (def x 1)
  (def y false)
  (if-let* [a x
            b y]
           [a b])
  ;; nil
  )

Here is the new if-let* imp:

(defmacro if-let*
  ([bindings then]
   `(if-let* ~bindings ~then nil))
  ([bindings then else]
   (if (seq bindings)
     `(if-let [~(first bindings) ~(second bindings)]
        (if-let* ~(drop 2 bindings) ~then ~else)
        ~(if-not (second bindings) else))
     then)))

(if-let* [a 1
           b (+ a 1) ]
           b)
;;=> 2

(if-let* [a 1
           b (+ a 1)
           c  false] ;;false or nil - does not matter
           b
           a)

;;=> 1