Unlike ';', which skips everything until a newline, a ':' skips just itself.
What do y'all think of this idea? Does it pop up any weird interactions?
I'm not sure ':' is the right character for this. It has the pleasing symmetry that these are now always equivalent.
Credits: David Wheeler and almkglor on readable-discuss (http://sourceforge.net/mailarchive/message.php?msg_id=29539336)
(f a b c :d d)
(f : a : b : c :d d)