/// <summary>
/// Interprets stored bytes as UTF8 bytes, returning the
/// resulting <see cref="string"/>.
/// </summary>
public string Utf8ToString()
{
CharsRef @ref = new CharsRef(Length);
UnicodeUtil.UTF8toUTF16(bytes, Offset, Length, @ref);
return(@ref.ToString());
}
/// <summary>
/// Interprets the given byte array as UTF-8 and converts to UTF-16. The <see cref="CharsRef"/> will be extended if
/// it doesn't provide enough space to hold the worst case of each byte becoming a UTF-16 codepoint.
/// <para/>
/// NOTE: Full characters are read, even if this reads past the length passed (and
/// can result in an <see cref="IndexOutOfRangeException"/> if invalid UTF-8 is passed).
/// Explicit checks for valid UTF-8 are not performed.
/// </summary>
// TODO: broken if chars.offset != 0
public static void UTF8toUTF16(byte[] utf8, int offset, int length, CharsRef chars)
{
int out_offset = chars.Offset = 0;
char[] @out = chars.Chars = ArrayUtil.Grow(chars.Chars, length);
int limit = offset + length;
while (offset < limit)
{
int b = utf8[offset++] & 0xff;
if (b < 0xc0)
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert(b < 0x80);
}
@out[out_offset++] = (char)b;
}
else if (b < 0xe0)
{
@out[out_offset++] = (char)(((b & 0x1f) << 6) + (utf8[offset++] & 0x3f));
}
else if (b < 0xf0)
{
@out[out_offset++] = (char)(((b & 0xf) << 12) + ((utf8[offset] & 0x3f) << 6) + (utf8[offset + 1] & 0x3f));
offset += 2;
}
else
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert(b < 0xf8, "b = 0x{0:x}", b);
}
int ch = ((b & 0x7) << 18) + ((utf8[offset] & 0x3f) << 12) + ((utf8[offset + 1] & 0x3f) << 6) + (utf8[offset + 2] & 0x3f);
offset += 3;
if (ch < UNI_MAX_BMP)
{
@out[out_offset++] = (char)ch;
}
else
{
int chHalf = ch - 0x0010000;
@out[out_offset++] = (char)((chHalf >> 10) + 0xD800);
@out[out_offset++] = (char)((chHalf & HALF_MASK) + 0xDC00);
}
}
}
chars.Length = out_offset - chars.Offset;
}
public static void UTF8toUTF16(BytesRef bytesRef, CharsRef chars)
{
UTF8toUTF16(bytesRef.Bytes, bytesRef.Offset, bytesRef.Length, chars);
}
