text: // 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.
  
  #pragma once
  
  #include <string>
  
  #include "gandiva/arrow.h"
  #include "gandiva/gandiva_aliases.h"
  #include "gandiva/visibility.h"
  
  namespace gandiva {
  
  /// \brief An expression tree with a root node, and a result field.
  class GANDIVA_EXPORT Expression {
   public:
    Expression(const NodePtr root, const FieldPtr result) : root_(root), result_(result) {}
  
    virtual ~Expression() = default;
  
    const NodePtr& root() const { return root_; }
  
    const FieldPtr& result() const { return result_; }
  
    std::string ToString();
  
   private:
    const NodePtr root_;
    const FieldPtr result_;
  };
  
  }  // namespace gandiva
  