Clojure also prunes the excessive parentheses whenever the structure is obvious from context. E.g. "(let ((a 1) (b 2)) ...)" becomes "(let [a 1 b 2] ...)" and Clojure just requires an even number of elements so that the pairing can be inferred.
Common Lisp has this in the `setq` and `psetq` macros. E.g. exchange `x` and `y`:
(psetq x y y x)
You can easily have a nesting reduced binding macro, like (var (x 1 y 1) (list x y)), with sequential binding.
Untested:
(defmacro var (pairs &body body)
(if (oddp (length pairs))
(error "~s: variables and init-forms must occur pairwise" 'var))
`(let* ,(loop for (var init) on pairs by #'cddr
unless (and var (symbolp var)
(not (eql var t))
(not (keywordp var)))
do
(error "~s: ~s isn't a variable name" 'var var)
collect (list var init))
,@body)))
