refactor: start to refactor project

src/yycc/prelude/core.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+// Prelude section
+#include "../string.hpp"
+namespace yycc::prelude {
+
+#define NS_YYCC_STRING ::yycc::string
+
+    using u8char = NS_YYCC_STRING::u8char;
+    using u8string = NS_YYCC_STRING::u8string;
+    using u8string_view = NS_YYCC_STRING::u8string_view;
+
+#undef NS_YYCC_STRING
+
+} // namespace yycc::prelude
+
+// Expose all members
+using namespace yycc::prelude;