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Merge pull request #191 from twelsby/issue186

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Fixed Issue #186 - add strto(f|d|ld) overload wrappers, "-0.0" special case and FP trailing zero
This commit is contained in:
Niels
2016-01-24 17:21:22 +01:00
parent 9584a99a43 81b7079255
commit ad5d1dabb2
3 changed files with 576 additions and 807 deletions
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88
src/json.hpp.re2c
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@ -5604,10 +5604,16 @@ class basic_json
case value_t::number_float:
{
// 15 digits of precision allows round-trip IEEE 754
// string->double->string; to be safe, we read this value from
// std::numeric_limits<number_float_t>::digits10
o << std::setprecision(std::numeric_limits<number_float_t>::digits10) << m_value.number_float;
// If the number is an integer then output as a fixed with with precision 1
// to output "0.0", "1.0" etc as expected for some round trip tests otherwise
// 15 digits of precision allows round-trip IEEE 754 string->double->string;
// to be safe, we read this value from std::numeric_limits<number_float_t>::digits10
if (std::fmod(m_value.number_float, 1) == 0) o << std::fixed << std::setprecision(1);
else {
o.unsetf(std::ios_base::floatfield); // std::defaultfloat not supported in gcc version < 5
o << std::setprecision(std::numeric_limits<double>::digits10);
}
o << m_value.number_float;
return;
}
@ -7036,6 +7042,63 @@ class basic_json
return result;
}
/*!
@brief parse floating point number
This function (and its overloads) serves to select the most approprate
standard floating point number parsing function based on the type
supplied via the first parameter. Set this to
@a static_cast<number_float_t>(nullptr).
@param type the @ref number_float_t in use
@param endptr recieves a pointer to the first character after the number
@return the floating point number
*/
long double str_to_float_t(long double* /* type */, char** endptr) const
{
return std::strtold(reinterpret_cast<typename string_t::const_pointer>(m_start), endptr);
}
/*!
@brief parse floating point number
This function (and its overloads) serves to select the most approprate
standard floating point number parsing function based on the type
supplied via the first parameter. Set this to
@a static_cast<number_float_t>(nullptr).
@param type the @ref number_float_t in use
@param endptr recieves a pointer to the first character after the number
@return the floating point number
*/
double str_to_float_t(double* /* type */, char** endptr) const
{
return std::strtod(reinterpret_cast<typename string_t::const_pointer>(m_start), endptr);
}
/*!
@brief parse floating point number
This function (and its overloads) serves to select the most approprate
standard floating point number parsing function based on the type
supplied via the first parameter. Set this to
@a static_cast<number_float_t>(nullptr).
@param type the @ref number_float_t in use
@param endptr recieves a pointer to the first character after the number
@return the floating point number
*/
float str_to_float_t(float* /* type */, char** endptr) const
{
return std::strtof(reinterpret_cast<typename string_t::const_pointer>(m_start), endptr);
}
/*!
@brief return number value for number tokens
@ -7053,13 +7116,12 @@ class basic_json
@throw std::range_error if passed value is out of range
*/
long double get_number() const
number_float_t get_number() const
{
// conversion
typename string_t::value_type* endptr;
assert(m_start != nullptr);
const auto float_val = std::strtold(reinterpret_cast<typename string_t::const_pointer>(m_start),
&endptr);
number_float_t float_val = str_to_float_t(static_cast<number_float_t*>(nullptr), &endptr);
// return float_val if the whole number was translated and NAN
// otherwise
@ -7293,11 +7355,11 @@ class basic_json
case lexer::token_type::value_number:
{
auto float_val = m_lexer.get_number();
result.m_value = m_lexer.get_number();
// NAN is returned if token could not be translated
// completely
if (std::isnan(float_val))
if (std::isnan(result.m_value.number_float))
{
throw std::invalid_argument(std::string("parse error - ") +
m_lexer.get_token() + " is not a number");
@ -7305,9 +7367,10 @@ class basic_json
get_token();
// check if conversion loses precision
const auto int_val = static_cast<number_integer_t>(float_val);
if (float_val == static_cast<long double>(int_val))
// check if conversion loses precision (special case -0.0 always loses precision)
const auto int_val = static_cast<number_integer_t>(result.m_value.number_float);
if (result.m_value.number_float == static_cast<number_float_t>(int_val) &&
result.m_value.number_integer != json_value(-0.0f).number_integer)
{
// we would not lose precision -> return int
result.m_type = value_t::number_integer;
@ -7317,7 +7380,6 @@ class basic_json
{
// we would lose precision -> return float
result.m_type = value_t::number_float;
result.m_value = static_cast<number_float_t>(float_val);
}
break;
}