bool lex_match_id (struct lexer *, const char *);
bool lex_match_id_n (struct lexer *, const char *, size_t n);
bool lex_match_int (struct lexer *, int);
bool lex_match_id (struct lexer *, const char *);
bool lex_match_id_n (struct lexer *, const char *, size_t n);
bool lex_match_int (struct lexer *, int);