text: // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
  
  #pragma once
  
  #include <vespa/eval/eval/function.h>
  
  namespace search {
  namespace features {
  namespace rankingexpression {
  
  /**
   * Custom symbol extractor used to extract ranking feature names when
   * parsing ranking expressions.
   **/
  struct FeatureNameExtractor : public vespalib::eval::SymbolExtractor {
      void extract_symbol(const char *pos_in, const char *end_in,
                          const char *&pos_out, vespalib::string &symbol_out) const override;
  };
  
  } // namespace rankingexpression
  } // namespace features
  } // namespace search
  
  