feat: basically finish parser helper.

- basically finish parser helper, including TryParse, Parse and ToString.
- only Parse has been tested. other test should be filled in future.

src/IOHelper.hpp

@@ -5,8 +5,18 @@
 #include <cstdio>
 
 namespace YYCC::IOHelper {
+	
+	/**
+	 * @brief Set given FILE* as UTF8 mode.
+	 * @param fs[in] The FILE* need to be set as UTF8 mode.
+	 * @return True if success, otherwise false.
+	 * @warning Once this function success, you can not use any narrow char function on this FILE*,
+	 * such as std::fputs, std::fprintf and etc. You only can use wide char function on it,
+	 * or use the functions provided in this namespace by providing UTF8 string as their argument.
+	*/
+	bool futf8(FILE* fs);
 
-	FILE* FOpen(const char* u8_filepath, const char* u8_mode);
+	FILE* fopen(const char* u8_filepath, const char* u8_mode);
 
 }