anchor.diff:  	     (cl:format stream "Spurious '~A' modifier:~%  => ~S~%  => ~V@T^"
   	       (modifier error)
   	       (format-string error)
  -	       (1+ (offset error)))))
  +	       (1+ (string-position error)))))
     (:documentation "A spurious modifier error."))
   
   (define-condition missing-delimiter (format-string-error)
  
positive.code: 	:and atsignp := nil
  	:for char := (if (< index end)
  			 (schar string index)
  		       (error 'missing-directive
  			      :format-string string
  			      :offset start))
  	:when (and (or colonp atsignp)
  		   (or (char<= #\0 char #\9)
  		       (member char '(#\- #\+ #\v #\V #\# #\' #\,))))
  	  :do (error 'spurious-parameter
  		     :format-string string
  		     :offset index)
  	:do (flet ((skip-comma (&optional (advance t))
  		     (when advance (incf index))
  		     (when (and (< index end)
  
negative.code: 		    ((char= char #\')
  		     (incf index)
  		     (when (= index end)
  		       (error 'missing-string-directive
  			      :string string
  			      :position start))
  		     (skip-comma))
  		    ((char= char #\,)
  		     (incf index))
  		    ((char= char #\:)
  		     (if colonp
  			 (error 'spurious-modifier
  				:string string
  				:position index
  				:modifier #\:)
  		       (setf colonp t))
  		     (incf index))
  		    ((char= char #\@)
  		     (if atsignp
  			 (error 'spurious-modifier
  				:string string
  				:position index
  				:modifier #\@)
  		       (setf atsignp t))
  		     (incf index))
  