StringConverter.h

// Copyright (c) Stefano Cristiano
// SPDX-License-Identifier: MIT
#pragma once
#include "../Strings/StringView.h"
 
namespace SC
{
template <typename T>
struct Vector;
struct SC_COMPILER_EXPORT StringConverter;
struct String;
} // namespace SC
 
 
struct SC::StringConverter
{
    enum NullTermination
    {
        AddZeroTerminator,     
        DoNotAddZeroTerminator 
    };
 
    [[nodiscard]] static bool convertEncodingToUTF8(StringView text, Vector<char>& buffer,
                                                    StringView*     encodedText   = nullptr,
                                                    NullTermination nullTerminate = AddZeroTerminator);
 
    [[nodiscard]] static bool convertEncodingToUTF16(StringView text, Vector<char>& buffer,
                                                     StringView*     encodedText   = nullptr,
                                                     NullTermination nullTerminate = AddZeroTerminator);
 
    [[nodiscard]] static bool convertEncodingTo(StringEncoding encoding, StringView text, Vector<char>& buffer,
                                                StringView*     encodedText   = nullptr,
                                                NullTermination nullTerminate = AddZeroTerminator);
 
    enum Flags
    {
        Clear,     
        DoNotClear 
    };
 
    StringConverter(String& text, Flags flags = DoNotClear);
 
    StringConverter(Vector<char>& text, StringEncoding encoding);
 
    [[nodiscard]] bool convertNullTerminateFastPath(StringView input, StringView& encodedText);
 
    [[nodiscard]] bool appendNullTerminated(StringView input, bool popExistingNullTerminator = true);
 
  private:
    [[nodiscard]] static bool popNullTermIfNotEmpty(Vector<char>& stringData, StringEncoding encoding);
 
    [[nodiscard]] static bool pushNullTerm(Vector<char>& stringData, StringEncoding encoding);
 
    [[nodiscard]] static bool ensureZeroTermination(Vector<char>& data, StringEncoding encoding);
 
    void internalClear();
    // TODO: FileSystemIterator should just use a Vector<char>
    friend struct FileSystemIterator;
    template <int N>
    friend struct SmallString;
    friend struct StringBuilder;
    friend struct FileDescriptor;
 
    [[nodiscard]] bool        setTextLengthInBytesIncludingTerminator(size_t newDataSize);
    [[nodiscard]] static bool convertSameEncoding(StringView text, Vector<char>& buffer, StringView* encodedText,
                                                  NullTermination terminate);
    static void               eventuallyNullTerminate(Vector<char>& buffer, StringEncoding destinationEncoding,
                                                      StringView* encodedText, NullTermination terminate);
 
    StringEncoding encoding;
    Vector<char>&  data;
    // Appends the input string null terminated
    [[nodiscard]] bool internalAppend(StringView input, StringView* encodedText);
 
    // Fallbacks for platforms without an API to do the conversion out of the box (Linux)
    [[nodiscard]] static bool convertUTF16LE_to_UTF8(const StringView sourceUtf16, Vector<char>& destination,
                                                     int& writtenCodeUnits);
    [[nodiscard]] static bool convertUTF8_to_UTF16LE(const StringView sourceUtf8, Vector<char>& destination,
                                                     int& writtenCodeUnits);
};