mirror of
https://github.com/nlohmann/json
synced 2024-12-03 08:41:04 +00:00
Added locale-independent numtostr
This commit is contained in:
Alex Astashyn
parent
bc28942101
commit
21cae35930
179
src/json.hpp
179
src/json.hpp
@ -2180,14 +2180,6 @@ class basic_json
|
||||
string_t dump(const int indent = -1) const
|
||||
{
|
||||
std::stringstream ss;
|
||||
// fix locale problems
|
||||
ss.imbue(std::locale::classic());
|
||||
|
||||
// 6, 15 or 16 digits of precision allows round-trip IEEE 754
|
||||
// string->float->string, string->double->string or string->long
|
||||
// double->string; to be safe, we read this value from
|
||||
// std::numeric_limits<number_float_t>::digits10
|
||||
ss.precision(std::numeric_limits<double>::digits10);
|
||||
|
||||
if (indent >= 0)
|
||||
{
|
||||
@ -5878,10 +5870,6 @@ class basic_json
|
||||
`std::setw(4)` on @a o sets the indentation level to `4` and the
|
||||
serialization result is the same as calling `dump(4)`.
|
||||
|
||||
@note During serializaion, the locale and the precision of the output
|
||||
stream @a o are changed. The original values are restored when the
|
||||
function returns.
|
||||
|
||||
@param[in,out] o stream to serialize to
|
||||
@param[in] j JSON value to serialize
|
||||
|
||||
@ -5903,22 +5891,9 @@ class basic_json
|
||||
// reset width to 0 for subsequent calls to this stream
|
||||
o.width(0);
|
||||
|
||||
// fix locale problems
|
||||
const auto old_locale = o.imbue(std::locale::classic());
|
||||
// set precision
|
||||
|
||||
// 6, 15 or 16 digits of precision allows round-trip IEEE 754
|
||||
// string->float->string, string->double->string or string->long
|
||||
// double->string; to be safe, we read this value from
|
||||
// std::numeric_limits<number_float_t>::digits10
|
||||
const auto old_precision = o.precision(std::numeric_limits<double>::digits10);
|
||||
|
||||
// do the actual serialization
|
||||
j.dump(o, pretty_print, static_cast<unsigned int>(indentation));
|
||||
|
||||
// reset locale and precision
|
||||
o.imbue(old_locale);
|
||||
o.precision(old_precision);
|
||||
return o;
|
||||
}
|
||||
|
||||
@ -6419,6 +6394,146 @@ class basic_json
|
||||
return result;
|
||||
}
|
||||
|
||||
|
||||
/*!
|
||||
@brief locale-independent serialization for built-in arithmetic types
|
||||
*/
|
||||
struct numtostr
|
||||
{
|
||||
public:
|
||||
template<typename T>
|
||||
numtostr(T value)
|
||||
{
|
||||
x_write(value, std::is_integral<T>());
|
||||
}
|
||||
|
||||
operator const char*() const
|
||||
{
|
||||
return m_buf.data();
|
||||
}
|
||||
|
||||
const char* c_str() const
|
||||
{
|
||||
return m_buf.data();
|
||||
}
|
||||
|
||||
private:
|
||||
static constexpr size_t s_capacity = 30;
|
||||
std::array<char, s_capacity + 2> m_buf{};
|
||||
|
||||
template<typename T>
|
||||
void x_write(T x, std::true_type)
|
||||
{
|
||||
const bool is_neg = x < 0;
|
||||
size_t i = 0;
|
||||
|
||||
while(x and i < s_capacity)
|
||||
{
|
||||
m_buf[i++] = '0' + abs(x % 10);
|
||||
x /= 10;
|
||||
}
|
||||
|
||||
if(i == s_capacity)
|
||||
{
|
||||
std::runtime_error(
|
||||
"Number is unexpectedly long: "
|
||||
+ std::to_string(x));
|
||||
}
|
||||
|
||||
if(i == 0)
|
||||
{
|
||||
m_buf[i++] = '0';
|
||||
}
|
||||
|
||||
if(is_neg)
|
||||
{
|
||||
m_buf[i++] = '-';
|
||||
}
|
||||
|
||||
std::reverse(m_buf.begin(), m_buf.begin() + i);
|
||||
}
|
||||
|
||||
template<typename T>
|
||||
void x_write(T x, std::false_type)
|
||||
{
|
||||
if (x == 0)
|
||||
{
|
||||
std::strcpy(m_buf.data(),
|
||||
std::signbit(x) ? "-0.0" : "0.0");
|
||||
return;
|
||||
}
|
||||
|
||||
static constexpr auto d =
|
||||
std::numeric_limits<number_float_t>::digits10+1;
|
||||
|
||||
// I'm not sure why we need that +1 above, if at all,
|
||||
// but without it there's a unit-test that fails
|
||||
// that asserts precision of the output
|
||||
|
||||
static_assert(d == 6 or d == 15 or d == 16 or d == 17, "");
|
||||
static constexpr auto fmt = d == 6 ? "%.6g"
|
||||
: d == 15 ? "%.15g"
|
||||
: d == 16 ? "%.16g"
|
||||
: d == 17 ? "%.17g"
|
||||
: "%.18g";
|
||||
|
||||
snprintf(m_buf.data(), m_buf.size(), fmt, x);
|
||||
|
||||
const std::locale loc;
|
||||
|
||||
// erase thousands separator
|
||||
{
|
||||
const char sep =
|
||||
std::use_facet< std::numpunct<char> >(
|
||||
loc).thousands_sep();
|
||||
|
||||
auto end = std::remove(m_buf.begin(),
|
||||
m_buf.end(),
|
||||
sep);
|
||||
|
||||
std::fill(end, m_buf.end(), '\0');
|
||||
}
|
||||
|
||||
// convert decimal point to '.'
|
||||
{
|
||||
const char decimal_point =
|
||||
std::use_facet< std::numpunct<char> >(
|
||||
loc).decimal_point();
|
||||
|
||||
for(auto& c : m_buf)
|
||||
{
|
||||
if(decimal_point == '.') {
|
||||
break;
|
||||
}
|
||||
|
||||
if(c == decimal_point)
|
||||
{
|
||||
c = '.';
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// determine if need to apperd ".0"
|
||||
auto data_end = m_buf.begin() + strlen(m_buf.data());
|
||||
|
||||
const bool value_is_int_like =
|
||||
std::find_if(m_buf.begin(), data_end,
|
||||
[](const char c)
|
||||
{ return (c >= '0' and c <= '9')
|
||||
or c == '-'; })
|
||||
== data_end;
|
||||
|
||||
assert(data_end + 2 < m_buf.end());
|
||||
if(value_is_int_like)
|
||||
{
|
||||
strcat(m_buf.data(), ".0");
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
|
||||
/*!
|
||||
@brief internal implementation of the serialization function
|
||||
|
||||
@ -6538,27 +6653,19 @@ class basic_json
|
||||
|
||||
case value_t::number_integer:
|
||||
{
|
||||
o << m_value.number_integer;
|
||||
o << numtostr(m_value.number_integer).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
case value_t::number_unsigned:
|
||||
{
|
||||
o << m_value.number_unsigned;
|
||||
o << numtostr(m_value.number_unsigned).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
case value_t::number_float:
|
||||
{
|
||||
if (m_value.number_float == 0)
|
||||
{
|
||||
// special case for zero to get "0.0"/"-0.0"
|
||||
o << (std::signbit(m_value.number_float) ? "-0.0" : "0.0");
|
||||
}
|
||||
else
|
||||
{
|
||||
o << m_value.number_float;
|
||||
}
|
||||
o << numtostr(m_value.number_float).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
@ -2180,14 +2180,6 @@ class basic_json
|
||||
string_t dump(const int indent = -1) const
|
||||
{
|
||||
std::stringstream ss;
|
||||
// fix locale problems
|
||||
ss.imbue(std::locale::classic());
|
||||
|
||||
// 6, 15 or 16 digits of precision allows round-trip IEEE 754
|
||||
// string->float->string, string->double->string or string->long
|
||||
// double->string; to be safe, we read this value from
|
||||
// std::numeric_limits<number_float_t>::digits10
|
||||
ss.precision(std::numeric_limits<double>::digits10);
|
||||
|
||||
if (indent >= 0)
|
||||
{
|
||||
@ -5878,10 +5870,6 @@ class basic_json
|
||||
`std::setw(4)` on @a o sets the indentation level to `4` and the
|
||||
serialization result is the same as calling `dump(4)`.
|
||||
|
||||
@note During serializaion, the locale and the precision of the output
|
||||
stream @a o are changed. The original values are restored when the
|
||||
function returns.
|
||||
|
||||
@param[in,out] o stream to serialize to
|
||||
@param[in] j JSON value to serialize
|
||||
|
||||
@ -5903,22 +5891,9 @@ class basic_json
|
||||
// reset width to 0 for subsequent calls to this stream
|
||||
o.width(0);
|
||||
|
||||
// fix locale problems
|
||||
const auto old_locale = o.imbue(std::locale::classic());
|
||||
// set precision
|
||||
|
||||
// 6, 15 or 16 digits of precision allows round-trip IEEE 754
|
||||
// string->float->string, string->double->string or string->long
|
||||
// double->string; to be safe, we read this value from
|
||||
// std::numeric_limits<number_float_t>::digits10
|
||||
const auto old_precision = o.precision(std::numeric_limits<double>::digits10);
|
||||
|
||||
// do the actual serialization
|
||||
j.dump(o, pretty_print, static_cast<unsigned int>(indentation));
|
||||
|
||||
// reset locale and precision
|
||||
o.imbue(old_locale);
|
||||
o.precision(old_precision);
|
||||
return o;
|
||||
}
|
||||
|
||||
@ -6419,6 +6394,146 @@ class basic_json
|
||||
return result;
|
||||
}
|
||||
|
||||
|
||||
/*!
|
||||
@brief locale-independent serialization for built-in arithmetic types
|
||||
*/
|
||||
struct numtostr
|
||||
{
|
||||
public:
|
||||
template<typename T>
|
||||
numtostr(T value)
|
||||
{
|
||||
x_write(value, std::is_integral<T>());
|
||||
}
|
||||
|
||||
operator const char*() const
|
||||
{
|
||||
return m_buf.data();
|
||||
}
|
||||
|
||||
const char* c_str() const
|
||||
{
|
||||
return m_buf.data();
|
||||
}
|
||||
|
||||
private:
|
||||
static constexpr size_t s_capacity = 30;
|
||||
std::array<char, s_capacity + 2> m_buf{};
|
||||
|
||||
template<typename T>
|
||||
void x_write(T x, std::true_type)
|
||||
{
|
||||
const bool is_neg = x < 0;
|
||||
size_t i = 0;
|
||||
|
||||
while(x and i < s_capacity)
|
||||
{
|
||||
m_buf[i++] = '0' + abs(x % 10);
|
||||
x /= 10;
|
||||
}
|
||||
|
||||
if(i == s_capacity)
|
||||
{
|
||||
std::runtime_error(
|
||||
"Number is unexpectedly long: "
|
||||
+ std::to_string(x));
|
||||
}
|
||||
|
||||
if(i == 0)
|
||||
{
|
||||
m_buf[i++] = '0';
|
||||
}
|
||||
|
||||
if(is_neg)
|
||||
{
|
||||
m_buf[i++] = '-';
|
||||
}
|
||||
|
||||
std::reverse(m_buf.begin(), m_buf.begin() + i);
|
||||
}
|
||||
|
||||
template<typename T>
|
||||
void x_write(T x, std::false_type)
|
||||
{
|
||||
if (x == 0)
|
||||
{
|
||||
std::strcpy(m_buf.data(),
|
||||
std::signbit(x) ? "-0.0" : "0.0");
|
||||
return;
|
||||
}
|
||||
|
||||
static constexpr auto d =
|
||||
std::numeric_limits<number_float_t>::digits10+1;
|
||||
|
||||
// I'm not sure why we need that +1 above, if at all,
|
||||
// but without it there's a unit-test that fails
|
||||
// that asserts precision of the output
|
||||
|
||||
static_assert(d == 6 or d == 15 or d == 16 or d == 17, "");
|
||||
static constexpr auto fmt = d == 6 ? "%.6g"
|
||||
: d == 15 ? "%.15g"
|
||||
: d == 16 ? "%.16g"
|
||||
: d == 17 ? "%.17g"
|
||||
: "%.18g";
|
||||
|
||||
snprintf(m_buf.data(), m_buf.size(), fmt, x);
|
||||
|
||||
const std::locale loc;
|
||||
|
||||
// erase thousands separator
|
||||
{
|
||||
const char sep =
|
||||
std::use_facet< std::numpunct<char> >(
|
||||
loc).thousands_sep();
|
||||
|
||||
auto end = std::remove(m_buf.begin(),
|
||||
m_buf.end(),
|
||||
sep);
|
||||
|
||||
std::fill(end, m_buf.end(), '\0');
|
||||
}
|
||||
|
||||
// convert decimal point to '.'
|
||||
{
|
||||
const char decimal_point =
|
||||
std::use_facet< std::numpunct<char> >(
|
||||
loc).decimal_point();
|
||||
|
||||
for(auto& c : m_buf)
|
||||
{
|
||||
if(decimal_point == '.') {
|
||||
break;
|
||||
}
|
||||
|
||||
if(c == decimal_point)
|
||||
{
|
||||
c = '.';
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// determine if need to apperd ".0"
|
||||
auto data_end = m_buf.begin() + strlen(m_buf.data());
|
||||
|
||||
const bool value_is_int_like =
|
||||
std::find_if(m_buf.begin(), data_end,
|
||||
[](const char c)
|
||||
{ return (c >= '0' and c <= '9')
|
||||
or c == '-'; })
|
||||
== data_end;
|
||||
|
||||
assert(data_end + 2 < m_buf.end());
|
||||
if(value_is_int_like)
|
||||
{
|
||||
strcat(m_buf.data(), ".0");
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
|
||||
/*!
|
||||
@brief internal implementation of the serialization function
|
||||
|
||||
@ -6538,27 +6653,19 @@ class basic_json
|
||||
|
||||
case value_t::number_integer:
|
||||
{
|
||||
o << m_value.number_integer;
|
||||
o << numtostr(m_value.number_integer).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
case value_t::number_unsigned:
|
||||
{
|
||||
o << m_value.number_unsigned;
|
||||
o << numtostr(m_value.number_unsigned).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
case value_t::number_float:
|
||||
{
|
||||
if (m_value.number_float == 0)
|
||||
{
|
||||
// special case for zero to get "0.0"/"-0.0"
|
||||
o << (std::signbit(m_value.number_float) ? "-0.0" : "0.0");
|
||||
}
|
||||
else
|
||||
{
|
||||
o << m_value.number_float;
|
||||
}
|
||||
o << numtostr(m_value.number_float).c_str();
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user