(labels((m(o)(if(atom o)`(,o)o))(f(l)(if(cdr l)(f(if(equal"."#1=(car l))`(,@#2=(m(cadr l))(,@(m(nth 2 l)),(nth 3 l)),@(cddddr l))`((,#1#,(f #2#)),@(cddr l))))#1#)))(loop(format t"~A "(f(asdf::split(read-line))))))
Note that non-ascii characters in the above source code will be escaped (such as \x9f).