anchor.diff:                :validator (or (and validator (clavier:&& (clavier:valid-email)
                                                           (make-validator validator)))
                                (clavier:valid-email))
  -              :if-invalid (or (parse-if-invalid if-invalid)
  +              :if-invalid (or (parse-if-invalid if-invalid error-color)
                                 (lambda (&optional value)
                                   (declare (ignore value))
                                   (say "Invalid email" :color error-color)))
  
positive.code:           :parser #'chronicity:parse
            :default default
            :required-p required-p
            :if-invalid (or (parse-if-invalid if-invalid)
                            (lambda () (say "Error. Invalid timestamp"
                                            :color error-color)))
            :color color
  
negative.code:                          (return nil))
                          ((not parsed-input)
                           (if if-invalid
                               (funcall (parse-if-invalid if-invalid error-color))
                               (say "Invalid value" :color error-color)))
                          (parsed-input
                           (return parsed-input)))))))
  