Function: Read characters from STREAM while they are token constituents (according to RFC 2616). It is assumed that there's a token character at the current position. The token read is returned as a string. Doesn't signal an error (but simply stops reading) if END-OF-FILE is encountered after the first character.
(defuncontinue-p ()
"Ask user if we should continue looking for solutions."
(case (read-char)
(#\; t)
(#\. nil)
(#\Newline (continue-p))
(otherwise
(format t
" Type ; to see more or . to stop")
(continue-p))))