Add support for '%' type to output floating point values as a

percentage.

This helps with compatibility with Python's format strings.
This commit is contained in:
gawain 2019-03-01 20:32:05 +01:00 committed by Victor Zverovich
parent 287eaab3b2
commit 79b79f329e
3 changed files with 45 additions and 8 deletions

View File

@ -539,8 +539,7 @@ struct fixed_stop {
void on_exp(int exp) {
if (!fixed) return;
exp += exp10;
if (exp >= 0)
precision += exp;
if (exp >= 0) precision += exp;
}
bool operator()(char*, int& size, uint64_t remainder, uint64_t divisor,
@ -656,7 +655,13 @@ void sprintf_format(Double value, internal::buffer& buf,
*format_ptr++ = '*';
}
if (std::is_same<Double, long double>::value) *format_ptr++ = 'L';
char type = spec.type ? spec.type : 'g';
char type = spec.type;
if (type == '%')
type = 'f';
else if (type == 0)
type = 'g';
#if FMT_MSC_VER
if (type == 'F') {
// MSVC's printf doesn't support 'F'.

View File

@ -1274,6 +1274,9 @@ FMT_CONSTEXPR void handle_float_type_spec(char spec, Handler&& handler) {
case 'F':
handler.on_fixed();
break;
case '%':
handler.on_percent();
break;
case 'a':
case 'A':
handler.on_hex();
@ -1338,6 +1341,7 @@ class float_type_checker : private ErrorHandler {
FMT_CONSTEXPR void on_general() {}
FMT_CONSTEXPR void on_exp() {}
FMT_CONSTEXPR void on_fixed() {}
FMT_CONSTEXPR void on_percent() {}
FMT_CONSTEXPR void on_hex() {}
FMT_CONSTEXPR void on_error() {
@ -2642,10 +2646,12 @@ template <typename Range> class basic_writer {
struct inf_or_nan_writer {
char sign;
bool as_percentage;
const char* str;
size_t size() const {
return static_cast<std::size_t>(INF_SIZE + (sign ? 1 : 0));
return static_cast<std::size_t>(INF_SIZE + (sign ? 1 : 0) +
(as_percentage ? 1 : 0));
}
size_t width() const { return size(); }
@ -2653,6 +2659,7 @@ template <typename Range> class basic_writer {
if (sign) *it++ = static_cast<char_type>(sign);
it = internal::copy_str<char_type>(
str, str + static_cast<std::size_t>(INF_SIZE), it);
if (as_percentage) *it++ = static_cast<char_type>('%');
}
};
@ -2810,8 +2817,10 @@ struct float_spec_handler {
char type;
bool upper;
bool fixed;
bool as_percentage;
explicit float_spec_handler(char t) : type(t), upper(false), fixed(false) {}
explicit float_spec_handler(char t)
: type(t), upper(false), fixed(false), as_percentage(false) {}
void on_general() {
if (type == 'G') upper = true;
@ -2826,6 +2835,11 @@ struct float_spec_handler {
if (type == 'F') upper = true;
}
void on_percent() {
fixed = true;
as_percentage = true;
}
void on_hex() {
if (type == 'A') upper = true;
}
@ -2854,10 +2868,11 @@ void basic_writer<Range>::write_double(T value, const format_specs& spec) {
basic_writer& writer;
format_specs spec;
char sign;
bool as_percentage;
void operator()(const char* str) const {
writer.write_padded(spec, inf_or_nan_writer{sign, str});
writer.write_padded(spec, inf_or_nan_writer{sign, as_percentage, str});
}
} write_inf_or_nan = {*this, spec, sign};
} write_inf_or_nan = {*this, spec, sign, handler.as_percentage};
// Format NaN and ininity ourselves because sprintf's output is not consistent
// across platforms.
@ -2869,11 +2884,19 @@ void basic_writer<Range>::write_double(T value, const format_specs& spec) {
memory_buffer buffer;
int exp = 0;
int precision = spec.has_precision() || !spec.type ? spec.precision : 6;
if (handler.as_percentage) value *= 100.;
bool use_grisu = fmt::internal::use_grisu<T>() &&
(!spec.type || handler.fixed) &&
internal::grisu2_format(static_cast<double>(value), buffer,
precision, handler.fixed, exp);
if (!use_grisu) internal::sprintf_format(value, buffer, spec);
if (handler.as_percentage) {
buffer.push_back('%');
--exp; // Adjust decimal place position.
}
align_spec as = spec;
if (spec.align() == ALIGN_NUMERIC) {
if (sign) {

View File

@ -1207,6 +1207,8 @@ TEST(FormatterTest, Precision) {
"precision not allowed for this argument type");
EXPECT_THROW_MSG(format("{0:.2f}", 42ull), format_error,
"precision not allowed for this argument type");
EXPECT_THROW_MSG(format("{0:.2%}", 42), format_error,
"precision not allowed for this argument type");
EXPECT_THROW_MSG(format("{0:3.0}", 'x'), format_error,
"precision not allowed for this argument type");
EXPECT_EQ("1.2", format("{0:.2}", 1.2345));
@ -1440,10 +1442,11 @@ TEST(FormatterTest, FormatConvertibleToLongLong) {
TEST(FormatterTest, FormatFloat) {
EXPECT_EQ("392.500000", format("{0:f}", 392.5f));
EXPECT_EQ("12.500000%", format("{0:%}", 0.125f));
}
TEST(FormatterTest, FormatDouble) {
check_unknown_types(1.2, "eEfFgGaA", "double");
check_unknown_types(1.2, "eEfFgGaA%", "double");
EXPECT_EQ("0.0", format("{:}", 0.0));
EXPECT_EQ("0.000000", format("{:f}", 0.0));
EXPECT_EQ("0", format("{:g}", 0.0));
@ -1452,6 +1455,8 @@ TEST(FormatterTest, FormatDouble) {
EXPECT_EQ("392.65", format("{:G}", 392.65));
EXPECT_EQ("392.650000", format("{:f}", 392.65));
EXPECT_EQ("392.650000", format("{:F}", 392.65));
EXPECT_EQ("12.500000%", format("{:%}", 0.125));
EXPECT_EQ("12.34%", format("{:.2%}", 0.1234432));
char buffer[BUFFER_SIZE];
safe_sprintf(buffer, "%e", 392.65);
EXPECT_EQ(buffer, format("{0:e}", 392.65));
@ -1473,6 +1478,7 @@ TEST(FormatterTest, FormatNaN) {
EXPECT_EQ("nan ", format("{:<7}", nan));
EXPECT_EQ(" nan ", format("{:^7}", nan));
EXPECT_EQ(" nan", format("{:>7}", nan));
EXPECT_EQ("nan%", format("{:%}", nan));
}
TEST(FormatterTest, FormatInfinity) {
@ -1485,6 +1491,7 @@ TEST(FormatterTest, FormatInfinity) {
EXPECT_EQ("inf ", format("{:<7}", inf));
EXPECT_EQ(" inf ", format("{:^7}", inf));
EXPECT_EQ(" inf", format("{:>7}", inf));
EXPECT_EQ("inf%", format("{:%}", inf));
}
TEST(FormatterTest, FormatLongDouble) {
@ -1495,6 +1502,8 @@ TEST(FormatterTest, FormatLongDouble) {
EXPECT_EQ("392.65", format("{0:G}", 392.65l));
EXPECT_EQ("392.650000", format("{0:f}", 392.65l));
EXPECT_EQ("392.650000", format("{0:F}", 392.65l));
EXPECT_EQ("12.500000%", format("{:%}", 0.125l));
EXPECT_EQ("12.34%", format("{:.2%}", 0.1234432l));
char buffer[BUFFER_SIZE];
safe_sprintf(buffer, "%Le", 392.65l);
EXPECT_EQ(buffer, format("{0:e}", 392.65l));