Method: (ENSURE-VALID-COMPONENT-LABEL CONTAINER T)

Documentation

Returns T is LABEL names one of the component in CONTAINER. Otherwise a restartable error is signaled.

Source

(defmethod ensure-valid-component-label ((container container) label)
  "Returns T is LABEL names one of the component in CONTAINER.

Otherwise a restartable error is signaled."
  (if (find-component container label)
      t
      (restart-case
          (error "No component named ~S in container ~S [~S]."
                 label container (container.contents container))
        (use-first ()
          :report (lambda (stream)
                    (format stream "Use the first component in the container (~S)"
                            (cdr (first (container.contents container)))))
          (cdr (first (container.contents container)))))))