@base-ui-components/react/esm/combobox/root/utils/constants.js

Base UI is a library of headless ('unstyled') React components and low-level hooks. You gain complete control over your app's CSS and accessibility features.

export const NO_ACTIVE_VALUE = Symbol('none');
export const INITIAL_LAST_HIGHLIGHT = {
  value: NO_ACTIVE_VALUE,
  index: -1
};