bool ss_match_string (struct substring *, const struct substring);
int ss_get_char (struct substring *);
size_t ss_get_chars (struct substring *, size_t cnt, struct substring *);
bool ss_match_string (struct substring *, const struct substring);
int ss_get_char (struct substring *);
size_t ss_get_chars (struct substring *, size_t cnt, struct substring *);