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 com.google.common.collect.ImmutableList;
  
  /**
   * Measure SQL type.
   *
   * <p>The type serves as a tag that the measure must be expanded
   * into an expression before use.
   */
  public class MeasureSqlType extends ApplySqlType {
    /** Private constructor. */
    private MeasureSqlType(RelDataType elementType, boolean isNullable) {
      super(SqlTypeName.MEASURE, isNullable, ImmutableList.of(elementType));
      computeDigest();
    }
  
    @Override public RelDataType getMeasureElementType() {
      return types.get(0);
    }
  
    /** Creates a MeasureSqlType. */
    static MeasureSqlType create(RelDataType elementType) {
      return new MeasureSqlType(elementType, elementType.isNullable());
    }
  }
  