* vertical transformation (i.e. when {@link #isVertical()} is true).
   */
  public abstract double transform(double x);

  /**
   * Returns the inverse linear transformation. The inverse of a horizontal transformation is a
   * vertical transformation, and vice versa. The inverse of the {@link #forNaN} transformation is

/**
 * Standard transformer implementation for the Fess search engine.
 * This transformer handles document transformation and content extraction using
 * the standard Fess file transformation process with support for various content types.
 *
 * <p>It extends AbstractFessFileTransformer to provide file-specific transformation
 * capabilities while using the appropriate extractor for each document type.</p>
 */

import jakarta.annotation.PostConstruct;

/**
 * File transformer implementation for the Fess search engine.
 * This transformer handles file-based document transformation and content extraction
 * using the Fess file transformation process with support for various file types.
 *
 * <p>It extends AbstractFessFileTransformer to provide specialized file processing

  /**
   * UTF-8: eight-bit UCS Transformation Format.
   *
   * @deprecated Use {@link StandardCharsets#UTF_8} instead.
   */
  @Deprecated public static final Charset UTF_8 = StandardCharsets.UTF_8;

  /**
   * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
   *
   * @deprecated Use {@link StandardCharsets#UTF_16BE} instead.
   */

    }

    /**
     * Returns the transformation.
     *
     * @return the transformation
     */
    public String getTransformation() {
        return transformation;
    }

    /**
     * Sets the transformation.
     *
     * @param transformation
     *            the transformation
     */
    public void setTransformation(final String transformation) {

import org.lastaflute.web.validation.Required;

/**
 * Form for uploading character mapping files to the Fess search engine.
 * Character mapping allows for normalization and transformation of characters during text analysis.
 * This form is used in the admin interface to upload custom character mapping dictionary files.
 */
public class UploadForm {

    /**

/**
 * Response processor implementation for the Fess search engine.
 * This processor extends DefaultResponseProcessor to provide additional
 * processing capabilities through the ingest framework, allowing for
 * custom data transformation and enrichment during the crawling process.
 *
 * <p>It supports pluggable ingesters that can modify the result data
 * before it is stored in the search index.</p>
 */

/**
 * Implementation of IndexUpdateCallback for handling document indexing operations.
 * This class manages the process of updating the search index with documents from
 * data stores, including bulk operations, document transformation, and error handling.
 */
public class IndexUpdateCallbackImpl implements IndexUpdateCallback {
    private static final Logger logger = LogManager.getLogger(IndexUpdateCallbackImpl.class);

    /**

    //
    /** Logger for this class. */
    private static final Logger logger = LogManager.getLogger(GoAction.class);

    /** Helper for URL path mapping and transformation. */
    @Resource
    protected PathMappingHelper pathMappingHelper;

    // ===================================================================================

   *     the returned future.
   * @param executor Executor to run the function in.
   * @return A future that holds result of the transformation.
   * @since 9.0 (in 2.0 as {@code compose})
   */
  public static <I extends @Nullable Object, O extends @Nullable Object>
      ListenableFuture<O> transform(