-int scan(const string &path, int fd, dev_t parent_dev, dir_time modified, dir_time db_modified, ExistingDB *existing_db, Corpus *corpus, DictionaryBuilder *dict_builder)
+int scan(const string &path, int fd, dev_t parent_dev, dir_time modified, dir_time db_modified, ExistingDB *existing_db, DatabaseReceiver *corpus, DictionaryBuilder *dict_builder)