【lucene】IndexOptions

public enum IndexOptions {
  // NOTE: order is important here; enum ordinals can be used to compare options.
  /** Not indexed */
  NONE,
  /**
   * Only documents are indexed: term frequencies and positions are omitted. Phrase and other
   * positional queries on the field will throw an exception, and scoring will behave as if any term
   * in the document appears only once.
   */
  DOCS,
  /**
   * Only documents and term frequencies are indexed: positions are omitted. This enables normal
   * scoring, except Phrase and other positional queries will throw an exception.
   */
  DOCS_AND_FREQS,
  /**
   * Indexes documents, frequencies and positions. This is a typical default for full-text search:
   * full scoring is enabled and positional queries are supported.
   */
  DOCS_AND_FREQS_AND_POSITIONS,
  /**
   * Indexes documents, frequencies, positions and offsets. Character offsets are encoded alongside
   * the positions.
   */
  DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS,
}