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.rex;
  
  import org.apache.calcite.rel.type.RelDataType;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * A row-expression which references a field.
   */
  public abstract class RexVariable extends RexNode {
    //~ Instance fields --------------------------------------------------------
  
    protected final String name;
    protected final RelDataType type;
  
    //~ Constructors -----------------------------------------------------------
  
    protected RexVariable(
        String name,
        RelDataType type) {
      this.name = requireNonNull(name, "name");
      this.digest = requireNonNull(name, "name");
      this.type = requireNonNull(type, "type");
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public RelDataType getType() {
      return type;
    }
  
    /**
     * Returns the name of this variable.
     */
    public String getName() {
      return name;
    }
  }
  