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: ;; ==========================================================================
  
  (define-condition format-string-error (focus-error)
    ((format-string :documentation "The format string related to the error."
  		  :initarg :format-string
  		  :reader format-string)
     (offset :documentation "The offset in the string where the error occurs."
  	   :initform nil
  	   :initarg :offset
  	   :reader offset))
    (:documentation "A format string error."))
  
  (define-condition missing-directive (format-string-error)
    ()
    (:report (lambda (error stream)
  	     (cl:format stream
  		 "Missing directive character:~%  => ~S~%  => ~V@T^"
  	       (format-string error)
  	       (1+ (offset error)))))
    (:documentation "A missing directive error."))
  
  (define-condition spurious-parameter (format-string-error)
  
negative.code: 		      (directive-character directive))
  		    (1+ closing-character))
  	  (error 'missing-delimiter
  		 :string string
  		 :position start
  		 :delimiter character)))))
    (:method (string start (directive function-directive))
      "Method for function directives."
  