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.fun;
  
  import org.apache.calcite.sql.SqlBinaryOperator;
  import org.apache.calcite.sql.SqlKind;
  import org.apache.calcite.sql.type.InferTypes;
  import org.apache.calcite.sql.type.OperandTypes;
  import org.apache.calcite.sql.type.ReturnTypes;
  
  /**
   * An operator which performs set operations on multisets, such as "MULTISET
   * UNION ALL".
   *
   * <p>Not to be confused with {@link SqlMultisetValueConstructor} or
   * {@link SqlMultisetQueryConstructor}.
   *
   * <p>todo: Represent the ALL keyword to MULTISET UNION ALL etc. as a hidden
   * operand. Then we can obsolete this class.
   */
  public class SqlMultisetSetOperator extends SqlBinaryOperator {
    //~ Instance fields --------------------------------------------------------
  
    @SuppressWarnings("unused")
    private final boolean all;
  
    //~ Constructors -----------------------------------------------------------
  
    public SqlMultisetSetOperator(String name, int prec, boolean all) {
      super(
          name,
          SqlKind.OTHER,
          prec,
          true,
          ReturnTypes.MULTISET_NULLABLE,
          InferTypes.FIRST_KNOWN,
          OperandTypes.MULTISET_MULTISET);
      this.all = all;
    }
  }
  