diff --git a/include/fmt/format.h b/include/fmt/format.h index fe78bbfd..5a4ac688 100644 --- a/include/fmt/format.h +++ b/include/fmt/format.h @@ -1204,157 +1204,6 @@ template struct basic_format_specs { using format_specs = basic_format_specs; namespace detail { - -// A floating-point presentation format. -enum class float_format : unsigned char { - general, // General: exponent notation or fixed point based on magnitude. - exp, // Exponent notation with the default precision of 6, e.g. 1.2e-3. - fixed, // Fixed point with the default precision of 6, e.g. 0.0012. - hex -}; - -struct float_specs { - int precision; - float_format format : 8; - sign_t sign : 8; - bool upper : 1; - bool locale : 1; - bool binary32 : 1; - bool use_grisu : 1; - bool showpoint : 1; -}; - -// Writes the exponent exp in the form "[+-]d{2,3}" to buffer. -template It write_exponent(int exp, It it) { - FMT_ASSERT(-10000 < exp && exp < 10000, "exponent out of range"); - if (exp < 0) { - *it++ = static_cast('-'); - exp = -exp; - } else { - *it++ = static_cast('+'); - } - if (exp >= 100) { - const char* top = data::digits[exp / 100]; - if (exp >= 1000) *it++ = static_cast(top[0]); - *it++ = static_cast(top[1]); - exp %= 100; - } - const char* d = data::digits[exp]; - *it++ = static_cast(d[0]); - *it++ = static_cast(d[1]); - return it; -} - -template class float_writer { - private: - // The number is given as v = digits_ * pow(10, exp_). - const char* digits_; - int num_digits_; - int exp_; - size_t size_; - float_specs specs_; - Char decimal_point_; - - template It prettify(It it) const { - // pow(10, full_exp - 1) <= v <= pow(10, full_exp). - int full_exp = num_digits_ + exp_; - if (specs_.format == float_format::exp) { - // Insert a decimal point after the first digit and add an exponent. - *it++ = static_cast(*digits_); - int num_zeros = specs_.precision - num_digits_; - if (num_digits_ > 1 || specs_.showpoint) *it++ = decimal_point_; - it = copy_str(digits_ + 1, digits_ + num_digits_, it); - if (num_zeros > 0 && specs_.showpoint) - it = std::fill_n(it, num_zeros, static_cast('0')); - *it++ = static_cast(specs_.upper ? 'E' : 'e'); - return write_exponent(full_exp - 1, it); - } - if (num_digits_ <= full_exp) { - // 1234e7 -> 12340000000[.0+] - it = copy_str(digits_, digits_ + num_digits_, it); - it = std::fill_n(it, full_exp - num_digits_, static_cast('0')); - if (specs_.showpoint) { - *it++ = decimal_point_; - int num_zeros = specs_.precision - full_exp; - if (num_zeros <= 0) { - if (specs_.format != float_format::fixed) - *it++ = static_cast('0'); - return it; - } -#ifdef FMT_FUZZ - if (num_zeros > 5000) - throw std::runtime_error("fuzz mode - avoiding excessive cpu use"); -#endif - it = std::fill_n(it, num_zeros, static_cast('0')); - } - } else if (full_exp > 0) { - // 1234e-2 -> 12.34[0+] - it = copy_str(digits_, digits_ + full_exp, it); - if (!specs_.showpoint) { - if (num_digits_ != full_exp) *it++ = decimal_point_; - return copy_str(digits_ + full_exp, digits_ + num_digits_, it); - } - *it++ = decimal_point_; - it = copy_str(digits_ + full_exp, digits_ + num_digits_, it); - if (specs_.precision > num_digits_) { - // Add trailing zeros. - int num_zeros = specs_.precision - num_digits_; - it = std::fill_n(it, num_zeros, static_cast('0')); - } - } else { - // 1234e-6 -> 0.001234 - *it++ = static_cast('0'); - int num_zeros = -full_exp; - if (num_digits_ == 0 && specs_.precision >= 0 && - specs_.precision < num_zeros) { - num_zeros = specs_.precision; - } - if (num_zeros != 0 || num_digits_ != 0 || specs_.showpoint) { - *it++ = decimal_point_; - it = std::fill_n(it, num_zeros, static_cast('0')); - it = copy_str(digits_, digits_ + num_digits_, it); - } - } - return it; - } - - public: - float_writer(const char* digits, int num_digits, int exp, float_specs specs, - Char decimal_point) - : digits_(digits), - num_digits_(num_digits), - exp_(exp), - specs_(specs), - decimal_point_(decimal_point) { - int full_exp = num_digits + exp - 1; - int precision = specs.precision > 0 ? specs.precision : 16; - if (specs_.format == float_format::general && - !(full_exp >= -4 && full_exp < precision)) { - specs_.format = float_format::exp; - } - size_ = prettify(counting_iterator()).count(); - size_ += specs.sign ? 1 : 0; - } - - size_t size() const { return size_; } - - template It operator()(It it) const { - if (specs_.sign) *it++ = static_cast(data::signs[specs_.sign]); - return prettify(it); - } -}; - -template -int format_float(T value, int precision, float_specs specs, buffer& buf); - -// Formats a floating-point number with snprintf. -template -int snprintf_float(T value, int precision, float_specs specs, - buffer& buf); - -template T promote_float(T value) { return value; } -inline double promote_float(float value) { return static_cast(value); } - namespace dragonbox { // Type-specific information that Dragonbox uses. @@ -1421,6 +1270,160 @@ template struct decimal_fp { template decimal_fp to_decimal(T x) FMT_NOEXCEPT; } // namespace dragonbox +// A floating-point presentation format. +enum class float_format : unsigned char { + general, // General: exponent notation or fixed point based on magnitude. + exp, // Exponent notation with the default precision of 6, e.g. 1.2e-3. + fixed, // Fixed point with the default precision of 6, e.g. 0.0012. + hex +}; + +struct float_specs { + int precision; + float_format format : 8; + sign_t sign : 8; + bool upper : 1; + bool locale : 1; + bool binary32 : 1; + bool use_grisu : 1; + bool showpoint : 1; +}; + +// Writes the exponent exp in the form "[+-]d{2,3}" to buffer. +template It write_exponent(int exp, It it) { + FMT_ASSERT(-10000 < exp && exp < 10000, "exponent out of range"); + if (exp < 0) { + *it++ = static_cast('-'); + exp = -exp; + } else { + *it++ = static_cast('+'); + } + if (exp >= 100) { + const char* top = data::digits[exp / 100]; + if (exp >= 1000) *it++ = static_cast(top[0]); + *it++ = static_cast(top[1]); + exp %= 100; + } + const char* d = data::digits[exp]; + *it++ = static_cast(d[0]); + *it++ = static_cast(d[1]); + return it; +} + +template +OutputIt write_float(OutputIt it, const buffer& significand, int exp, + float_specs specs, Char decimal_point) { + const char* digits = significand.data(); + int num_digits = static_cast(significand.size()); + int full_exp = exp + num_digits; + auto format = specs.format; + if (format == float_format::general && + !(full_exp >= -3 && + full_exp < (specs.precision > 0 ? specs.precision : 16) + 1)) { + format = float_format::exp; + } + const Char zero = static_cast('0'); + if (format == float_format::exp) { + // Insert a decimal point after the first digit and add an exponent. + *it++ = static_cast(*digits); + int num_zeros = specs.precision - num_digits; + if (num_digits > 1 || specs.showpoint) *it++ = decimal_point; + it = copy_str(digits + 1, digits + num_digits, it); + if (num_zeros > 0 && specs.showpoint) it = std::fill_n(it, num_zeros, zero); + *it++ = static_cast(specs.upper ? 'E' : 'e'); + return write_exponent(full_exp - 1, it); + } + if (num_digits <= full_exp) { + // 1234e7 -> 12340000000[.0+] + it = copy_str(digits, digits + num_digits, it); + it = std::fill_n(it, full_exp - num_digits, zero); + if (specs.showpoint) { + *it++ = decimal_point; + int num_zeros = specs.precision - full_exp; + if (num_zeros <= 0) { + if (format != float_format::fixed) *it++ = zero; + return it; + } +#ifdef FMT_FUZZ + if (num_zeros > 5000) + throw std::runtime_error("fuzz mode - avoiding excessive cpu use"); +#endif + it = std::fill_n(it, num_zeros, zero); + } + } else if (full_exp > 0) { + // 1234e-2 -> 12.34[0+] + it = copy_str(digits, digits + full_exp, it); + if (!specs.showpoint) { + if (num_digits != full_exp) *it++ = decimal_point; + return copy_str(digits + full_exp, digits + num_digits, it); + } + *it++ = decimal_point; + it = copy_str(digits + full_exp, digits + num_digits, it); + if (specs.precision > num_digits) { + // Add trailing zeros. + int num_zeros = specs.precision - num_digits; + it = std::fill_n(it, num_zeros, zero); + } + } else { + // 1234e-6 -> 0.001234 + *it++ = zero; + int num_zeros = -full_exp; + if (num_digits == 0 && specs.precision >= 0 && + specs.precision < num_zeros) { + num_zeros = specs.precision; + } + if (num_zeros != 0 || num_digits != 0 || specs.showpoint) { + *it++ = decimal_point; + it = std::fill_n(it, num_zeros, zero); + it = copy_str(digits, digits + num_digits, it); + } + } + return it; +} + +template class float_writer { + private: + // The number is given as v = significand_ * pow(10, exp_). + const buffer& significand_; + int exp_; + size_t size_; + float_specs specs_; + Char decimal_point_; + + template It prettify(It it) const { + return write_float(it, significand_, exp_, specs_, decimal_point_); + } + + public: + float_writer(const buffer& significand, int exp, float_specs specs, + Char decimal_point) + : significand_(significand), + exp_(exp), + specs_(specs), + decimal_point_(decimal_point) { + size_ = prettify(counting_iterator()).count(); + size_ += specs.sign ? 1 : 0; + } + + size_t size() const { return size_; } + + template It operator()(It it) const { + if (specs_.sign) *it++ = static_cast(data::signs[specs_.sign]); + return prettify(it); + } +}; + +template +int format_float(T value, int precision, float_specs specs, buffer& buf); + +// Formats a floating-point number with snprintf. +template +int snprintf_float(T value, int precision, float_specs specs, + buffer& buf); + +template T promote_float(T value) { return value; } +inline double promote_float(float value) { return static_cast(value); } + template FMT_CONSTEXPR void handle_int_type_spec(char spec, Handler&& handler) { switch (spec) { @@ -1868,8 +1871,7 @@ OutputIt write(OutputIt out, T value, basic_format_specs specs, fspecs.precision = precision; Char point = fspecs.locale ? decimal_point(loc) : static_cast('.'); - float_writer w(buffer.data(), static_cast(buffer.size()), exp, - fspecs, point); + float_writer w(buffer, exp, fspecs, point); return write_padded(out, specs, w.size(), w); } @@ -1892,8 +1894,7 @@ OutputIt write(OutputIt out, T value) { auto dec = dragonbox::to_decimal(static_cast(value)); memory_buffer buf; write(buffer_appender(buf), dec.significand); - float_writer w(buf.data(), static_cast(buf.size()), dec.exponent, - fspecs, static_cast('.')); + float_writer w(buf, dec.exponent, fspecs, static_cast('.')); return base_iterator(out, w(reserve(out, w.size()))); }