gperf学习笔记（二）

关键字的定义：

struct Keyword
{
  /* Constructor.  */
                        Keyword (const char *allchars, int allchars_length,
                                 const char *rest);

  /* Data members defined immediately by the input file.  */
  /* The keyword as a string, possibly containing NUL bytes.  */
  const char *const     _allchars;
  int const             _allchars_length;
  /* Additional stuff seen on the same line of the input file.  */
  const char *const     _rest;
  /* Line number of this keyword in the input file.  */
  unsigned int          _lineno;
};

关键字的继承类：

 

struct KeywordExt : public Keyword
{
  /* Constructor.  */
                        KeywordExt (const char *allchars, int allchars_length,
                                    const char *rest);

  /* Data members depending on the keyposition list.  */
  /* The selected characters that participate for the hash function,
     selected according to the keyposition list, as a canonically reordered
     multiset.  */
  const unsigned int *  _selchars;
  int                   _selchars_length;
  /* Chained list of keywords having the same _selchars and
     - if !option[NOLENGTH] - also the same _allchars_length.
     Note that these duplicates are not members of the main keyword list.  */
  KeywordExt *          _duplicate_link;

  /* Methods depending on the keyposition list.  */
  /* Initializes selchars and selchars_length, without reordering.  */
  void                  init_selchars_tuple (const Positions& positions, const unsigned int *alpha_unify);
  /* Initializes selchars and selchars_length, with reordering.  */
  void                  init_selchars_multiset (const Positions& positions, const unsigned int *alpha_unify, const unsigned int *alpha_inc);
  /* Deletes selchars.  */
  void                  delete_selchars ();

  /* Data members used by the algorithm.  */
  int                   _hash_value; /* Hash value for the keyword.  */

  /* Data members used by the output routines.  */
  int                   _final_index;

private:
  unsigned int *        init_selchars_low (const Positions& positions, const unsigned int *alpha_unify, const unsigned int *alpha_inc);
};

创建关键字实例的类：

 

class Keyword_Factory
{
public:
  /* Constructor.  */
                        Keyword_Factory ();
  /* Destructor.  */
  virtual               ~Keyword_Factory ();

  /* Creates a new Keyword.  */
  virtual /*abstract*/ Keyword *
                        create_keyword (const char *allchars, int allchars_length,
                                        const char *rest) = 0;
};