refactor: start to refactor project

src/YYCCLegacy/StringHelper.cpp

@@ -0,0 +1,223 @@
+#include "StringHelper.hpp"
+#include "EncodingHelper.hpp"
+#include <algorithm>
+
+namespace YYCC::StringHelper {
+
+#pragma region Printf VPrintf
+
+	bool Printf(yycc_u8string& strl, const yycc_char8_t* format, ...) {
+		va_list argptr;
+		va_start(argptr, format);
+		bool ret = VPrintf(strl, format, argptr);
+		va_end(argptr);
+		return ret;
+	}
+
+	bool VPrintf(yycc_u8string& strl, const yycc_char8_t* format, va_list argptr) {
+		va_list args1;
+		va_copy(args1, argptr);
+		va_list args2;
+		va_copy(args2, argptr);
+
+		// the return value is desired char count without NULL terminal.
+		// minus number means error
+		int count = std::vsnprintf(
+			nullptr,
+			0,
+			EncodingHelper::ToOrdinary(format),
+			args1
+		);
+		if (count < 0) {
+			// invalid length returned by vsnprintf.
+			return false;
+		}
+		va_end(args1);
+
+		// resize std::string to desired count.
+		// and pass its length + 1 to std::vsnprintf,
+		// because std::vsnprintf only can write "buf_size - 1" chars with a trailing NULL.
+		// however std::vsnprintf already have a trailing NULL, so we plus 1 for it.
+		strl.resize(count);
+		int write_result = std::vsnprintf(
+			EncodingHelper::ToOrdinary(strl.data()),
+			strl.size() + 1,
+			EncodingHelper::ToOrdinary(format),
+			args2
+		);
+		va_end(args2);
+
+		if (write_result < 0 || write_result > count) {
+			// invalid write result in vsnprintf.
+			return false;
+		}
+
+		return true;
+	}
+
+	yycc_u8string Printf(const yycc_char8_t* format, ...) {
+		yycc_u8string ret;
+
+		va_list argptr;
+		va_start(argptr, format);
+		VPrintf(ret, format, argptr);
+		va_end(argptr);
+
+		return ret;
+	}
+
+	yycc_u8string VPrintf(const yycc_char8_t* format, va_list argptr) {
+		yycc_u8string ret;
+
+		va_list argcpy;
+		va_copy(argcpy, argptr);
+		VPrintf(ret, format, argcpy);
+		va_end(argcpy);
+
+		return ret;
+	}
+
+#pragma endregion
+
+#pragma region Replace
+
+	void Replace(yycc_u8string& strl, const yycc_u8string_view& _from_strl, const yycc_u8string_view& _to_strl) {
+		// Reference: https://stackoverflow.com/questions/3418231/replace-part-of-a-string-with-another-string
+
+		// check requirements
+		// from string should not be empty
+		yycc_u8string from_strl(_from_strl);
+		yycc_u8string to_strl(_to_strl);
+		if (from_strl.empty()) return;
+
+		// start replace one by one
+		size_t start_pos = 0;
+		while ((start_pos = strl.find(from_strl, start_pos)) != yycc_u8string::npos) {
+			strl.replace(start_pos, from_strl.size(), to_strl);
+			start_pos += to_strl.size(); // In case 'to' contains 'from', like replacing 'x' with 'yx'
+		}
+	}
+
+	yycc_u8string Replace(const yycc_u8string_view& _strl, const yycc_u8string_view& _from_strl, const yycc_u8string_view& _to_strl) {
+		// prepare result
+		yycc_u8string strl(_strl);
+		Replace(strl, _from_strl, _to_strl);
+		// return value
+		return strl;
+	}
+
+#pragma endregion
+
+#pragma region Join
+
+	yycc_u8string Join(JoinDataProvider fct_data, const yycc_u8string_view& decilmer) {
+		yycc_u8string ret;
+		bool is_first = true;
+		yycc_u8string_view element;
+
+		// fetch element
+		while (fct_data(element)) {
+			// insert decilmer
+			if (is_first) is_first = false;
+			else {
+				// append decilmer.
+				ret.append(decilmer);
+			}
+
+			// insert element if it is not empty
+			if (!element.empty())
+				ret.append(element);
+		}
+
+		return ret;
+	}
+
+#pragma endregion
+
+#pragma region Upper Lower
+
+	template<bool bIsToLower>
+	static void GeneralStringLowerUpper(yycc_u8string& strl) {
+		// References:
+		// https://en.cppreference.com/w/cpp/algorithm/transform
+		// https://en.cppreference.com/w/cpp/string/byte/tolower
+		std::transform(
+			strl.cbegin(), strl.cend(), strl.begin(),
+			[](unsigned char c) -> char {
+				if constexpr (bIsToLower) return std::tolower(c);
+				else return std::toupper(c);
+			}
+		);
+	}
+
+	void Lower(yycc_u8string& strl) {
+		GeneralStringLowerUpper<true>(strl);
+	}
+
+	yycc_u8string Lower(const yycc_u8string_view& strl) {
+		yycc_u8string ret(strl);
+		Lower(ret);
+		return ret;
+	}
+
+	void Upper(yycc_u8string& strl) {
+		GeneralStringLowerUpper<false>(strl);
+	}
+
+	yycc_u8string Upper(const yycc_u8string_view& strl) {
+		// same as Lower, just replace char transform function.
+		yycc_u8string ret(strl);
+		Upper(ret);
+		return ret;
+	}
+
+#pragma endregion
+
+#pragma region Split
+
+	std::vector<yycc_u8string> Split(const yycc_u8string_view& strl, const yycc_u8string_view& _decilmer) {
+		// call split view
+		auto view_result = SplitView(strl, _decilmer);
+
+		// copy string view result to string
+		std::vector<yycc_u8string> elems;
+		elems.reserve(view_result.size());
+		for (const auto& strl_view : view_result) {
+			elems.emplace_back(yycc_u8string(strl_view));
+		}
+		// return copied result
+		return elems;
+	}
+
+	std::vector<yycc_u8string_view> SplitView(const yycc_u8string_view& strl, const yycc_u8string_view& _decilmer) {
+		// Reference: 
+		// https://stackoverflow.com/questions/14265581/parse-split-a-string-in-c-using-string-delimiter-standard-c
+
+		// prepare return value
+		std::vector<yycc_u8string_view> elems;
+
+		// if string need to be splitted is empty, return original string (empty string).
+		// if decilmer is empty, return original string.
+		yycc_u8string decilmer(_decilmer);
+		if (strl.empty() || decilmer.empty()) {
+			elems.emplace_back(strl);
+			return elems;
+		}
+
+		// start spliting
+		std::size_t previous = 0, current;
+		while ((current = strl.find(decilmer.c_str(), previous)) != yycc_u8string::npos) {
+			elems.emplace_back(strl.substr(previous, current - previous));
+			previous = current + decilmer.size();
+		}
+		// try insert last part but prevent possible out of range exception
+		if (previous <= strl.size()) {
+			elems.emplace_back(strl.substr(previous));
+		}
+		return elems;
+	}
+
+#pragma endregion
+
+
+}