content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.runtime.variant;
  
  import org.apache.calcite.runtime.rtti.RuntimeTypeInformation;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.Objects;
  
  /** A VARIANT value that contains a NULL runtime value. */
  public class VariantSqlNull extends VariantSqlValue {
    VariantSqlNull(RuntimeTypeInformation.RuntimeSqlTypeName runtimeType) {
      super(runtimeType);
    }
  
    @Override public @Nullable Object item(Object index) {
      // Result is always null
      return null;
    }
  
    @Override public @Nullable Object cast(RuntimeTypeInformation type) {
      // Result is always null
      return null;
    }
  
    @Override public String toString() {
      return "NULL";
    }
  
    @Override public int hashCode() {
      return Objects.hashCode(runtimeType);
    }
  
    @Override public boolean equals(@Nullable Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
  
      VariantSqlNull variant = (VariantSqlNull) o;
      return runtimeType == variant.runtimeType;
    }
  }
  