anchor.diff:  (defvar *read-suppress* nil)
   
   (defvar *read-lookahead-table*)
  +(defvar *read-package* nil)
   
   (declaim (special *readtable* *standard-readtable*)
            (type readtable *readtable* *standard-readtable*))
  
positive.code:         (when (eql (char token offset) #\.)
            (incf dot-count))))
      (cond
        ;; Return a symbol immediately if a package marker was seen.
        (package-name
         (if (or intern-symbol (string= "KEYWORD" package-name))
  
negative.code:       ;; If an escape character was seen, then do not try to parse the token as
        ;; an number, intern it and return it immediately.
        (seen-escape
         (intern token *read-package*))
        ;; Attempt to parse a number.
        (t (or (read-integer token)
               (read-float token)
               (read-ratio token stream)
               (intern token *read-package*))))))
  
  (defun read-ratio (string stream)
    ;; ratio = sign? digits+ slash digits+
  