for (i = 0, *out = 0; is_xdigit(scanner_peek(s)) && i < 2; i++) {
const char c = scanner_next(s);
const char offset = (c >= '0' && c <= '9' ? '0' :
c >= 'a' && c <= 'f' ? 'a' - 10 : 'A' - 10);
for (i = 0, *out = 0; is_xdigit(scanner_peek(s)) && i < 2; i++) {
const char c = scanner_next(s);
const char offset = (c >= '0' && c <= '9' ? '0' :
c >= 'a' && c <= 'f' ? 'a' - 10 : 'A' - 10);