feat: update pycodec.

- rename encoding::utf to encoding::stlcvt.
- use uv to manage script and add pycodec generator script.
- update script in modern python.
- fix added pycodec generator.

src/yycc/encoding/stlcvt.hpp

@@ -0,0 +1,40 @@
+#pragma once
+#include "../string.hpp"
+#include "../patch/expected.hpp"
+
+#define NS_YYCC_STRING ::yycc::string
+#define NS_YYCC_PATCH_EXPECTED ::yycc::patch::expected
+
+namespace yycc::encoding::stlcvt {
+
+    /// @private
+    struct ConvError {};
+
+    /// @private
+    template<typename T>
+    using ConvResult = NS_YYCC_PATCH_EXPECTED::Expected<T, ConvError>;
+
+    // UTF8 -> UTF16
+    ConvResult<std::u16string> priv_to_utf16(const NS_YYCC_STRING::u8string_view& src);
+    bool to_utf16(const NS_YYCC_STRING::u8string_view& src, std::u16string& dst);
+    std::u16string to_utf16(const NS_YYCC_STRING::u8string_view& src);
+
+    // UTF16 -> UTF8
+    ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u16string_view& src);
+    bool to_utf8(const std::u16string_view& src, NS_YYCC_STRING::u8string& dst);
+    NS_YYCC_STRING::u8string to_utf8(const std::u16string_view& src);
+
+    // UTF8 -> UTF32
+    ConvResult<std::u32string> priv_to_utf32(const NS_YYCC_STRING::u8string_view& src);
+    bool to_utf32(const NS_YYCC_STRING::u8string_view& src, std::u32string& dst);
+    std::u32string to_utf32(const NS_YYCC_STRING::u8string_view& src);
+
+    // UTF32 -> UTF8
+    ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u32string_view& src);
+    bool to_utf8(const std::u32string_view& src, NS_YYCC_STRING::u8string& dst);
+    NS_YYCC_STRING::u8string to_utf8(const std::u32string_view& src);
+
+}
+
+#undef NS_YYCC_PATCH_EXPECTED
+#undef NS_YYCC_STRING