Column projection methods

RefinableView.java

  /**
   * Creates a copy of this {@code View} for entities of the given type class.
   *
   * @param type a Java Class to use for entities
   * @return a copy of this view for the given type
   * @throws org.kitesdk.data.IncompatibleSchemaException
   *          If the schema for {@code type} is incompatible with the
   *          underlying dataset's Schema.
   */
  <T> RefinableView<T> asType(Class<T> type);

  /**
   * Creates a copy of this {@code View} for the given {@link Schema}.
   * <p>
   * This method always returns a {@code View} for {@code GenericRecord}. To
   * use specific, reflect, or other records, use {@link #asType(Class)}.
   *
   * @param schema an Avro Schema to use for entities
   * @return a copy of this view for the given Schema
   * @throws org.kitesdk.data.IncompatibleSchemaException
   *          If the {@code schema} is incompatible with the underlying
   *          dataset's Schema.
   */
  <T extends GenericRecord> RefinableView<T> asSchema(Schema schema);

  /**
   * Creates a copy of this {@code View} with a {@link Schema} created from
   * only the given {@code fields}.
   * <p>
   * Each field must be present in the underlying dataset's Schema. The
   * returned view's Schema is constructed by adding each selected field to a
   * new Schema that is a filtered version of the initial Schema.
   *
   * @param fields a list of selected Avro Schema fields
   * @return a copy of this view for the given Schema
   * @throws java.lang.IllegalArgumentException
   *           If one of the selected {@code fields} is not present in the
   *           underlying dataset's Schema.
   */
  <T extends GenericRecord> RefinableView<T> select(String... fields);