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refactor: update ParserHelper

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- update the implementation of ParserHelper from locale-based std::to_string, std::stod, std::stoull, to locale-independent function std::from_chars and std::to_chars.
- rename TerminalHelper to ConsoleHelper.
This commit is contained in:
yyc12345
2024-05-31 12:12:48 +08:00
parent 7044a0cff2
commit 67bd445885
6 changed files with 81 additions and 57 deletions
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81
src/ParserHelper.hpp
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@ -6,55 +6,45 @@
#include <cinttypes>
#include <type_traits>
#include <stdexcept>
#include <limits>
#include <charconv>
#include <array>
namespace YYCC::ParserHelper {
template<class>
constexpr bool g_AlwaysFalse = false;
// Reference: https://zh.cppreference.com/w/cpp/utility/from_chars
template<typename _Ty, std::enable_if_t<std::is_floating_point_v<_Ty>, int> = 0>
bool TryParse(const std::string& strl, _Ty& num) {
try {
// float types
if constexpr (std::is_same_v<_Ty, float>) {
num = std::stof(strl, nullptr);
} else if constexpr (std::is_same_v<_Ty, double>) {
num = std::stod(strl, nullptr);
} else if constexpr (std::is_same_v<_Ty, long double>) {
num = std::stold(strl, nullptr);
} else {
static_assert(g_AlwaysFalse<_Ty>, "Invalid float type.");
}
return true;
} catch (const std::invalid_argument&) {
auto [ptr, ec] = std::from_chars(strl.c_str(), strl.c_str() + strl.size(), num, std::chars_format::general);
if (ec == std::errc()) {
// check whether the full string is matched
return ptr == strl.c_str() + strl.size();
} else if (ec == std::errc::invalid_argument) {
// given string is invalid
return false;
} catch (const std::out_of_range&) {
} else if (ec == std::errc::result_out_of_range) {
// given string is out of range
return false;
} else {
// unreachable
throw std::runtime_error("unreachable code.");
}
}
template<typename _Ty, std::enable_if_t<std::is_integral_v<_Ty> && !std::is_same_v<_Ty, bool>, int> = 0>
bool TryParse(const std::string& strl, _Ty& num, int base = 10) {
try {
// integer type
// decide integer type
using container_t = std::conditional_t<std::is_unsigned_v<_Ty>, unsigned long long, long long>;
// parse it from string according to whether integer type is signed.
container_t cache;
if constexpr (std::is_unsigned_v<_Ty>) {
cache = std::stoull(strl, nullptr, base);
} else {
cache = std::stoll(strl, nullptr, base);
}
// check its range
if (cache < std::numeric_limits<_Ty>::min() || cache > std::numeric_limits<_Ty>::max())
return false;
num = static_cast<_Ty>(cache);
return true;
} catch (const std::invalid_argument&) {
auto [ptr, ec] = std::from_chars(strl.c_str(), strl.c_str() + strl.size(), num, base);
if (ec == std::errc()) {
// check whether the full string is matched
return ptr == strl.c_str() + strl.size();
} else if (ec == std::errc::invalid_argument) {
// given string is invalid
return false;
} catch (const std::out_of_range&) {
} else if (ec == std::errc::result_out_of_range) {
// given string is out of range
return false;
} else {
// unreachable
throw std::runtime_error("unreachable code.");
}
}
template<typename _Ty, std::enable_if_t<std::is_same_v<_Ty, bool>, int> = 0>
@ -72,12 +62,25 @@ namespace YYCC::ParserHelper {
return ret;
}
template<typename _Ty, std::enable_if_t<std::is_arithmetic_v<_Ty>, int> = 0>
// Reference: https://en.cppreference.com/w/cpp/utility/to_chars
template<typename _Ty, std::enable_if_t<std::is_arithmetic_v<_Ty> && !std::is_same_v<_Ty, bool>, int> = 0>
std::string ToString(_Ty num) {
return std::to_string(num);
std::array<char, 64> buffer;
auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), num);
if (ec == std::errc()) {
return std::string(buffer.data(), ptr - buffer.data());
} else if (ec == std::errc::value_too_large) {
// too short buffer
// this should not happend
throw std::out_of_range("ToString() buffer is not sufficient.");
} else {
// unreachable
throw std::runtime_error("unreachable code.");
}
}
template<>
std::string ToString<bool>(bool num) {
template<typename _Ty, std::enable_if_t<std::is_same_v<_Ty, bool>, int> = 0>
std::string ToString(_Ty num) {
if (num) return std::string("true");
else return std::string("false");
}