text: #ifndef __HASH_H
  #define __HASH_H
  
  struct hash;
  
  struct hash *hash_new (int);
  void hash_free (struct hash *);
  unsigned long hash_lookup (struct hash *, unsigned long);
  int hash_insert (struct hash *, unsigned long, unsigned long);
  unsigned long hash_delete (struct hash *, unsigned long);
  
  #endif /* __HASH_H */
  
  