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* fix errors in the parse_number_string.

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This commit is contained in:
IRainman 2025-04-11 22:52:18 +03:00
parent 88b3887b52
commit 563648f76d
1 changed files with 19 additions and 12 deletions
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31
include/fast_float/ascii_number.h
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@ -260,6 +260,7 @@ enum class parse_error {
};
template <typename UC> struct parsed_number_string_t {
// an unsigned int avoids signed overflows (which are bad)
uint64_t mantissa{0};
int16_t exponent{0};
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
@ -328,7 +329,6 @@ parse_number_string(UC const *p, UC const *pend,
UC const *const start_digits = p;
// an unsigned int avoids signed overflows (which are bad)
while ((p != pend) && is_integer(*p)) {
// a multiplication by 10 is cheaper than an arbitrary integer
// multiplication
@ -359,7 +359,6 @@ parse_number_string(UC const *p, UC const *pend,
if (has_decimal_point) {
++p;
UC const *before = p;
uint16_t fraction = 0;
// can occur at most twice without overflowing, but let it occur more, since
// for integers with many digits, digit parsing is the primary bottleneck.
loop_parse_if_eight_digits(p, pend, answer.mantissa);
@ -371,13 +370,13 @@ parse_number_string(UC const *p, UC const *pend,
digit; // in rare cases, this will overflow, but that's ok
++p;
}
fraction = static_cast<uint16_t>(before - p);
answer.exponent = static_cast<int16_t>(before - p);
answer.fraction = span<UC const>(before, static_cast<uint16_t>(p - before));
digit_count -= fraction;
digit_count -= answer.exponent;
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
FASTFLOAT_IF_CONSTEXPR17(basic_json_fmt) {
// at least 1 digit in fractional part
if (has_decimal_point && fraction == 0) {
if (has_decimal_point && answer.exponent == 0) {
return report_parse_error<UC>(
p, parse_error::no_digits_in_fractional_part);
}
@ -389,7 +388,8 @@ parse_number_string(UC const *p, UC const *pend,
}
// We have now parsed the integer and the fraction part of the mantissa.
// Now we can parse the exponent part.
// Now we can parse the explicit exponential part.
int16_t exp_number = 0; // explicit exponential part
if ((p != pend) && (uint8_t(options.format & chars_format::scientific) &&
(UC('e') == *p) ||
(UC('E') == *p))
@ -400,8 +400,14 @@ parse_number_string(UC const *p, UC const *pend,
#endif
) {
UC const *location_of_e = p;
#ifdef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
++p;
#else
if ((UC('e') == *p) || (UC('E') == *p) || (UC('d') == *p) ||
(UC('D') == *p)) {
++p;
}
#endif
bool neg_exp = false;
if (p != pend) {
if (UC('-') == *p) {
@ -423,16 +429,17 @@ parse_number_string(UC const *p, UC const *pend,
p = location_of_e;
} else {
while ((p != pend) && is_integer(*p)) {
if (answer.exponent < 0x1000) {
if (exp_number < 0x1000) {
// check for exponent overflow if we have too many digits.
uint8_t const digit = uint8_t(*p - UC('0'));
answer.exponent = 10 * answer.exponent + digit;
exp_number = 10 * exp_number + digit;
}
++p;
}
if (neg_exp) {
answer.exponent = -answer.exponent;
exp_number = -exp_number;
}
answer.exponent += exp_number;
}
} else {
// If it scientific and not fixed, we have to bail out.
@ -479,7 +486,7 @@ parse_number_string(UC const *p, UC const *pend,
}
if (answer.mantissa >=
minimal_nineteen_digit_integer) { // We have a big integers
answer.exponent += int16_t(end_of_integer_part - p);
answer.exponent = int16_t(end_of_integer_part - p) + exp_number;
} else { // We have a value with a fractional component.
p = answer.fraction.ptr;
UC const *frac_end = p + answer.fraction.len();
@ -488,7 +495,7 @@ parse_number_string(UC const *p, UC const *pend,
answer.mantissa = answer.mantissa * 10 + uint64_t(*p - UC('0'));
++p;
}
answer.exponent += int16_t(answer.fraction.ptr - p);
answer.exponent = int16_t(answer.fraction.ptr - p) + exp_number;
}
// We have now corrected both exponent and mantissa, to a truncated value
}