anchor.diff:  ;;;;    2012-04-20 <PJB> Added conditions;
   ;;;;                     Added :start and :stop to ASCII-STRING and ASCII-BYTES.
   ;;;;                     Added ASCII-CONTROL-CODE-P and ASCII-PRINTABLE-CODE-P.
  +;;;;                     Completed the TEST function.
   ;;;;    2007-07-05 <PJB> Moved to public/lisp/common-lisp
   ;;;;    2006-10-01 <PJB> Created.
   ;;;;BUGS
  
positive.code:          and both CR and LF are mapped to #\newline.
  "
    (cond
      ((<= sp code 126)             (aref *ascii-characters* (- code sp)))
      ((or (= code cr) (= code lf)) #\newline)
      (t                            (ascii-error code))))
  
  
negative.code: 
  (defun test ()
    "
  DO:     test the ascii package; signal an error if something is wrong.
  RETURN: :success
  "
    (loop
       :for ch :across *ascii-characters*
  