anchor.diff:                                      (when (non-repeated-bool-field field)
                                         (incf bool-index))
                                       :bool-values bool-values)
  -             (incf field-offset)
  +             (declare (ignore offset-p))
  +             (when offset-p
  +               (incf field-offset))
                (if (proto-lazy-p field)
                    (collect-lazy-field field)
                    (collect-non-lazy-field field))
  
positive.code: 
  (defun process-field (field &key conc-name alias-for field-offset bool-index bool-values)
    "Process one field descriptor within 'define-message' or 'define-extend'.
  Returns a 'proto-field' object, a CLOS slot form, and the field index.
  
  Arguments
    FIELD: The description of the field as laid out in the proto schema.
  
negative.code:                `(setf (bit (,bit-field-name ,obj) ,bool-index)
                        ,(if default-form 1 0))
                 `(setf (,hidden-accessor-name ,obj) ,default-form))
            ,(when index
              `(setf (bit (,is-set-accessor ,obj) ,index) 0)))
  
          ;; Create defmethods to allow for getting/setting compatibly
          ;; with the standard-classes.
  