anchor.diff:  (defclass structure-start-lexeme (lisp-lexeme) ())
   (defclass pathname-start-lexeme (lisp-lexeme) ())
   (defclass undefined-reader-macro-lexeme (lisp-lexeme) ())
  -(defclass bit-vector-lexeme (form-lexeme) ())
  +(defclass bit-vector-form (form-lexeme complete-form-mixin) ())
   (defclass number-lexeme (form-lexeme complete-form-mixin) ())
   (defclass token-mixin () ())
   (defclass literal-object-lexeme (form-lexeme) ())
  
positive.code: 			       (if (and (not (end-of-buffer-p scan))
  					(constituentp (object-after scan)))
  				   (make-instance 'error-lexeme)
  				   (make-instance 'bit-vector-lexeme)))
  			  (#\: (fo)
  			       (make-instance 'uninterned-symbol-lexeme))
  			  (#\. (fo)
  
negative.code: (defmethod token-to-object ((syntax lisp-syntax) (token complete-function-form) &rest args &key &allow-other-keys)
    (fdefinition (apply #'token-to-object syntax (second (children token)) args)))
  
  (defmethod token-to-object ((syntax lisp-syntax) (token bit-vector-form)
                              &key &allow-other-keys)
    (read-from-string (token-string syntax token)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Arglist fetching.
  