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.sql.type;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeFamily;
  import org.apache.calcite.rel.type.RelDataTypeField;
  import org.apache.calcite.rel.type.RelDataTypeImpl;
  import org.apache.calcite.rel.type.RelDataTypePrecedenceList;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.io.Serializable;
  import java.util.List;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Abstract base class for SQL implementations of {@link RelDataType}.
   */
  public abstract class AbstractSqlType
      extends RelDataTypeImpl
      implements Cloneable, Serializable {
    //~ Instance fields --------------------------------------------------------
  
    protected final SqlTypeName typeName;
    protected final boolean isNullable;
  
    //~ Constructors -----------------------------------------------------------
  
    /**
     * Creates an AbstractSqlType.
     *
     * @param typeName   Type name
     * @param isNullable Whether nullable
     * @param fields     Fields of type, or null if not a record type
     */
    protected AbstractSqlType(
        SqlTypeName typeName,
        boolean isNullable,
        @Nullable List<? extends RelDataTypeField> fields) {
      super(fields);
      this.typeName = requireNonNull(typeName, "typeName");
      this.isNullable = isNullable || (typeName == SqlTypeName.NULL);
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public SqlTypeName getSqlTypeName() {
      return typeName;
    }
  
    @Override public boolean isNullable() {
      return isNullable;
    }
  
    @Override public RelDataTypeFamily getFamily() {
      SqlTypeFamily family = typeName.getFamily();
      // If typename does not have family, treat the current type as the only member its family
      return family != null ? family : this;
    }
  
    @Override public RelDataTypePrecedenceList getPrecedenceList() {
      RelDataTypePrecedenceList list =
          SqlTypeExplicitPrecedenceList.getListForType(this);
      if (list != null) {
        return list;
      }
      return super.getPrecedenceList();
    }
  }
  