Make yason:encode emit property lists

encode-plists.cl

(defmethod yason:encode :around ((object list) &optional (stream *standard-output*))
  "If *lists-as-plists*, encode OBJECT as plist 
if object satisfies #'plistp and every key is a keyword.
Otherwise encode as list."
  (if (and (boundp '*lists-as-plists*) 
	   *lists-as-plists*
	   (system:plistp object) 
	   (loop for key in object by 'cddr
	      always (keywordp key)))
      (yason:encode-plist object stream)
      (call-next-method)))

(let ((*lists-as-plists* t))
  (declare (special *lists-as-plists*))
  (yason:encode '(:foo 1 :bar ((:zot 2)))))
-> {"FOO":1,"BAR":[{"ZOT":2}]}(:FOO 1 :BAR ((:ZOT 2)))

(yason:encode '(:foo 1 :bar ((:zot 2))))
-> ["FOO",1,"BAR",[["ZOT",2]]](:FOO 1 :BAR ((:ZOT 2)))