- (defmacro push (x place)
- (multiple-value-bind (dummies vals newval setter getter)
- (get-setf-expansion place)
- (let ((g (gensym)))
- `(let* ((,g ,x)
- ,@(mapcar #'list dummies vals)
- (,(car newval) (cons ,g ,getter))
- ,@(cdr newval))
- ,setter))))
-