List of pending catch tags

[Dick Gabriel <RPG@SU-AI.ARPA>]

Despite what many people believe, the Common Lisp designers have left
some programs out of the Common Lisp spec, so you, the user, can have
some fun too and write your own. If you're interested in maintaining
a list of pending catch tags, write it yourself with a special, called
something like *PENDING-TAGS*. Then you can write:

(defmacro memo-catch (tag form)
	  `(let ((*pending-tags* *pending-tags*)
		 (tag ,tag))
		(push tag *pending-tags*)
		(catch tag ,form)))

			-rpg-