🔀 merge #378 (for #362 and #454)

pull/496/head
Niels Lohmann 2017-02-16 09:24:45 +01:00
commit 6408402ad2
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GPG Key ID: 7F3CEA63AE251B69
3 changed files with 346 additions and 81 deletions

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@ -2646,14 +2646,6 @@ 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)
{
@ -6214,10 +6206,6 @@ 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 serialization, 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
@ -6239,22 +6227,9 @@ 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;
}
@ -8244,6 +8219,162 @@ 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{{}}; // +2 for leading '-'
// and trailing '\0'
template<typename T>
void x_write(T x, std::true_type)
{
static_assert(std::numeric_limits<T>::digits10 <= s_capacity, "");
const bool is_neg = x < 0;
size_t i = 0;
while (x and i < s_capacity)
{
const auto digit = std::labs(static_cast<long>(x % 10));
m_buf[i++] = static_cast<char>('0' + digit);
x /= 10;
}
assert(i < s_capacity);
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;
static_assert(d == 6 or d == 15 or d == 16 or d == 17, "");
static constexpr auto fmt = d == 6 ? "%.7g"
: d == 15 ? "%.16g"
: d == 16 ? "%.17g"
: d == 17 ? "%.18g"
: "%.19g";
// I'm not sure why we need to +1 the precision,
// but without it there's a unit-test that fails
// that asserts precision of the output
snprintf(m_buf.data(), m_buf.size(), fmt, x);
#if 0
// C locales and C++ locales are similar but
// different.
//
// If working with C++ streams we'd've used
// these, but for C formatting functions we
// have to use C locales (setlocale / localeconv),
// rather than C++ locales (std::locale installed
// by std::locale::global()).
const std::locale loc;
const char thousands_sep =
std::use_facet< std::numpunct<char>>(
loc).thousands_sep();
const char decimal_point =
std::use_facet< std::numpunct<char>>(
loc).decimal_point();
#else
const auto loc = localeconv();
assert(loc != nullptr);
const char thousands_sep = !loc->thousands_sep ? '\0'
: loc->thousands_sep[0];
const char decimal_point = !loc->decimal_point ? '\0'
: loc->decimal_point[0];
#endif
// erase thousands separator
if (thousands_sep)
{
auto end = std::remove(m_buf.begin(),
m_buf.end(),
thousands_sep);
std::fill(end, m_buf.end(), '\0');
}
// convert decimal point to '.'
if (decimal_point and decimal_point != '.')
{
for (auto& c : m_buf)
{
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 == '.'
or c == 'e'
or c == 'E';
})
== 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
@ -8363,27 +8494,19 @@ 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;
}

View File

@ -2646,14 +2646,6 @@ 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)
{
@ -6214,10 +6206,6 @@ 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 serialization, 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
@ -6239,22 +6227,9 @@ 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;
}
@ -8244,6 +8219,162 @@ 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{{}}; // +2 for leading '-'
// and trailing '\0'
template<typename T>
void x_write(T x, std::true_type)
{
static_assert(std::numeric_limits<T>::digits10 <= s_capacity, "");
const bool is_neg = x < 0;
size_t i = 0;
while (x and i < s_capacity)
{
const auto digit = std::labs(static_cast<long>(x % 10));
m_buf[i++] = static_cast<char>('0' + digit);
x /= 10;
}
assert(i < s_capacity);
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;
static_assert(d == 6 or d == 15 or d == 16 or d == 17, "");
static constexpr auto fmt = d == 6 ? "%.7g"
: d == 15 ? "%.16g"
: d == 16 ? "%.17g"
: d == 17 ? "%.18g"
: "%.19g";
// I'm not sure why we need to +1 the precision,
// but without it there's a unit-test that fails
// that asserts precision of the output
snprintf(m_buf.data(), m_buf.size(), fmt, x);
#if 0
// C locales and C++ locales are similar but
// different.
//
// If working with C++ streams we'd've used
// these, but for C formatting functions we
// have to use C locales (setlocale / localeconv),
// rather than C++ locales (std::locale installed
// by std::locale::global()).
const std::locale loc;
const char thousands_sep =
std::use_facet< std::numpunct<char>>(
loc).thousands_sep();
const char decimal_point =
std::use_facet< std::numpunct<char>>(
loc).decimal_point();
#else
const auto loc = localeconv();
assert(loc != nullptr);
const char thousands_sep = !loc->thousands_sep ? '\0'
: loc->thousands_sep[0];
const char decimal_point = !loc->decimal_point ? '\0'
: loc->decimal_point[0];
#endif
// erase thousands separator
if (thousands_sep)
{
auto end = std::remove(m_buf.begin(),
m_buf.end(),
thousands_sep);
std::fill(end, m_buf.end(), '\0');
}
// convert decimal point to '.'
if (decimal_point and decimal_point != '.')
{
for (auto& c : m_buf)
{
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 == '.'
or c == 'e'
or c == 'E';
})
== 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
@ -8363,27 +8494,19 @@ 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;
}

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@ -402,15 +402,35 @@ TEST_CASE("regression tests")
//issue #230
//CHECK(j2b.dump() == "23.42");
CHECK(j3a.dump() == "10000");
CHECK(j3b.dump() == "10000");
CHECK(j3c.dump() == "10000");
CHECK(j3a.dump() == "10000.0");
CHECK(j3b.dump() == "10000.0");
CHECK(j3c.dump() == "10000.0");
//CHECK(j3b.dump() == "1E04"); // roundtrip error
//CHECK(j3c.dump() == "1e04"); // roundtrip error
std::locale::global(orig_locale);
}
SECTION("issue #378 - locale-independent num-to-str")
{
setlocale(LC_NUMERIC, "de_DE.UTF-8");
// Verify that snprintf uses special decimal and grouping characters.
// Disabled, because can't trigger locale-specific behavior in AppVeyor
#ifndef _MSC_VER
{
std::array<char, 64> buf;
std::snprintf(buf.data(), buf.size(), "%.2f", 12345.67);
CHECK(strcmp(buf.data(), "12345,67") == 0);
}
#endif
// verify that dumped correctly with '.' and no grouping
const json j1 = 12345.67;
CHECK(json(12345.67).dump() == "12345.67");
setlocale(LC_NUMERIC, "C");
}
SECTION("issue #379 - locale-independent str-to-num")
{
setlocale(LC_NUMERIC, "de_DE.UTF-8");
@ -434,7 +454,6 @@ TEST_CASE("regression tests")
CHECK(json::parse("1.000000000000000000000000000000000000000000000000000000000000000000000000").get<double>() == 1.0);
}
SECTION("issue #233 - Can't use basic_json::iterator as a base iterator for std::move_iterator")
{
json source = {"a", "b", "c"};
@ -749,9 +768,9 @@ TEST_CASE("regression tests")
CHECK_THROWS_AS(json::parse(vec), std::invalid_argument);
}
//SECTION("issue #454 - doubles are printed as integers")
//{
// json j = R"({"bool_value":true,"double_value":2.0,"int_value":10,"level1":{"list_value":[3,"hi",false],"tmp":5.0},"string_value":"hello"})"_json;
// CHECK(j["double_value"].is_number_integer());
//}
SECTION("issue #454 - doubles are printed as integers")
{
json j = R"({"bool_value":true,"double_value":2.0,"int_value":10,"level1":{"list_value":[3,"hi",false],"tmp":5.0},"string_value":"hello"})"_json;
CHECK(j["double_value"].is_number_float());
}
}