yyc12345
c85830902b
- add compiler hint for checking the arguments of printf. - change the return value of printf. from std::expected to normal value. use C++ exception to indicate error. * the error of printf usually caused by programmer. so it can be found when testing program. * so i use std::logic_error to indicate this and programmer should fix this before releasing program. - change the use of encoding convertion. for those cases that convertion must be safe, we unwrap it directly.
47 lines
2.0 KiB
C++
47 lines
2.0 KiB
C++
#pragma once
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#include <string_view>
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#include <expected>
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/**
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* @brief The namespace replicating Linux-specialized function, "wcswidth", in all platforms.
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* @details
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* "wcswdith" is a specialized function in Linux.
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* It was not included in POSIX standard and only provided on Linux.
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* This function can fetch how many space which given string occupied in terminal.
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* This is essential and useful function in our library.
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* So I create this namespace to make "wcswidth" be available on all platforms.
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*
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* "wcswidth" is based on \c wchar_t. In Linux, \c wchar_t is 4-bytes length.
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* It can represent any characters without surrogate pair.
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* However, in Windows, \c wchar_t is 2-bytes length.
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* There is possible surrogate pair within \c wchar_t string, which is inconvenient for our programming.
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* So in this homebrew namespace, I forcelt use \c char32_t as the basic char type.
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*
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* Due to the requirements of mine, this implementation is slightly different with original one.
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* These differences are list below:
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*
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* \li We do not return negative value for Control Char in "wcwidth",
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* because we need to support the analyse of ANSI Escape Sequence.
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* \li Due to the previous change, the type of return value of "wcwidth" and "wcswidth"
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* are changed from \c int to \c size_t because there is no negative return value.
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* \li "wcswidth" now support ANSI Escape Sequence (e.g. terminal color).
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* So it can analyse colorful output with correct space.
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*/
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namespace yycc::carton::wcwidth {
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/// @brief Error occurs in this module
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enum class Error {
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BadAnsiEscSeq, ///< Bad char when processing ANSI Escape Sequence
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BadCsiSeq, ///< Bad char when processing CSI Sequence.
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};
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/// @brief Result type for this module
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template<typename T>
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using Result = std::expected<T, Error>;
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size_t wcwidth(char32_t wc);
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Result<size_t> wcswidth(const std::u32string_view& rhs);
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Result<size_t> wcswidth(const std::u8string_view& rhs);
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} // namespace yycc::carton::wcwidth
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