content: /*
   * Copyright © 2018-2025 Commonwealth Scientific and Industrial Research
   * Organisation (CSIRO) ABN 41 687 119 230.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package au.csiro.pathling.fhirpath.comparison;
  
  import jakarta.annotation.Nonnull;
  import org.apache.spark.sql.Column;
  import org.apache.spark.sql.functions;
  
  /**
   * An interface that defines methods for comparing two {@link Column} objects for equality and
   * inequality.
   *
   * @author Piotr Szul
   */
  public interface ColumnEquality {
  
    /**
     * Creates an equality comparison between two columns.
     *
     * @param left the left column
     * @param right the right column
     * @return a column representing the equality comparison
     */
    @Nonnull
    Column equalsTo(@Nonnull Column left, @Nonnull Column right);
  
    /**
     * Creates an inequality comparison between two columns.
     *
     * @param left the left column
     * @param right the right column
     * @return a column representing the inequality comparison
     */
    @Nonnull
    default Column notEqual(@Nonnull final Column left, @Nonnull final Column right) {
      return functions.not(equalsTo(left, right));
    }
  }
  