coffee/fast_float
1
0
Fork 0
mirror of https://github.com/fastfloat/fast_float.git synced 2025-12-06 16:56:57 +08:00
Code Issues Packages Projects Releases Wiki Activity

fix for the parse_number_string

Browse Source
This commit is contained in:
IRainman 2025-05-07 21:43:26 +03:00
parent 6b22957188
commit 3ee80c2da3
1 changed files with 51 additions and 86 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

137
include/fast_float/ascii_number.h
View File

@ -328,24 +328,15 @@ parse_number_string(UC const *p, UC const *pend,
#endif
UC const *const start_digits = p;
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
if (p != pend)
#endif
{
do {
if (is_integer(*p)) {
// a multiplication by 10 is cheaper than an arbitrary integer
// multiplication
answer.mantissa = static_cast<fast_float::am_mant_t>(
answer.mantissa * 10 +
static_cast<fast_float::am_mant_t>(
*p -
UC('0'))); // might overflow, we will handle the overflow later
++p;
} else {
break;
}
} while (p != pend);
while ((p != pend) && is_integer(*p)) {
// a multiplication by 10 is cheaper than an arbitrary integer
// multiplication
answer.mantissa = static_cast<fast_float::am_mant_t>(
answer.mantissa * 10 +
static_cast<fast_float::am_mant_t>(
*p - UC('0'))); // might overflow, we will handle the overflow later
++p;
}
UC const *const end_of_integer_part = p;
@ -370,7 +361,7 @@ parse_number_string(UC const *p, UC const *pend,
// We can now parse the fraction part of the mantissa.
if ((p != pend) && (*p == options.decimal_point)) {
++p;
UC const *before = p;
UC const *const before = p;
// 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);
@ -404,74 +395,46 @@ parse_number_string(UC const *p, UC const *pend,
// Now we can parse the explicit exponential part.
am_pow_t exp_number = 0; // explicit exponential part
bool neg_exp = false;
if (p != pend) {
UC const *location_of_e;
if (chars_format_t(options.format & chars_format::scientific)) {
switch (*p) {
case UC('e'):
case UC('E'):
location_of_e = p;
++p;
break;
default:
if (!chars_format_t(options.format & chars_format::fixed)) {
// It scientific and not fixed, we have to bail out.
return report_parse_error<UC>(p,
parse_error::missing_exponential_part);
}
// In fixed notation we will be ignoring the 'e'.
location_of_e = nullptr;
}
if (location_of_e && p != pend) {
switch (*p) {
case UC('-'):
neg_exp = true;
++p;
break;
case UC('+'): // '+' on exponent is allowed by C++17 20.19.3.(7.1)
++p;
break;
default:
// In scientific and fixed notations sign is optional.
break;
}
}
}
if ((p != pend) &&
(chars_format_t(options.format & chars_format::scientific) &&
((UC('e') == *p) || (UC('E') == *p)))
#ifndef FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
else if (chars_format_t(options.format & detail::basic_fortran_fmt)) {
switch (*p) {
case UC('d'):
case UC('D'):
++p;
break;
default:
// In Fortran the d symbol is optional.
break;
}
switch (*p) {
case UC('-'):
neg_exp = true;
location_of_e = p;
++p;
break;
case UC('+'):
location_of_e = p;
++p;
break;
default:
// In Fortran the sign is mandatory.
return report_parse_error<UC>(p, parse_error::missing_exponential_part);
}
|| (chars_format_t(options.format & detail::basic_fortran_fmt) &&
((UC('+') == *p) || (UC('-') == *p) || (UC('d') == *p) ||
(UC('D') == *p)))
#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
else {
location_of_e = nullptr;
bool neg_exp = false;
if (p != pend) {
if (UC('-') == *p) {
neg_exp = true;
++p;
} else if (UC('+') == *p) {
// '+' on exponent is allowed by C++17 20.19.3.(7.1)
++p;
}
}
if (location_of_e) {
// We have a valid scientific notation, let's parse the explicit
// exponent.
// We have now parsed the sign of the exponent.
if ((p == pend) || !is_integer(*p)) {
if (!(chars_format_t(options.format & chars_format::fixed))) {
// The exponential part is invalid for scientific notation, so it
// must be a trailing token for fixed notation. However, fixed
// notation is disabled, so report a scientific notation error.
return report_parse_error<UC>(p, parse_error::missing_exponential_part);
}
// Otherwise, we will be ignoring the 'e'.
p = location_of_e;
} else {
// Now let's parse the explicit exponent.
while ((p != pend) && is_integer(*p)) {
if (exp_number < 0x1000) {
// check for exponent overflow if we have too many digits.
@ -484,9 +447,11 @@ parse_number_string(UC const *p, UC const *pend,
exp_number = -exp_number;
}
answer.exponent += exp_number;
} else if (chars_format_t(options.format & chars_format::scientific) &&
!chars_format_t(options.format & chars_format::fixed)) {
// If it scientific and not fixed, we have to bail out.
}
} else {
// If it scientific and not fixed, we have to bail out.
if ((chars_format_t(options.format & chars_format::scientific)) &&
!(chars_format_t(options.format & chars_format::fixed))) {
return report_parse_error<UC>(p, parse_error::missing_exponential_part);
}
}