public static Rune FromUtf16(byte[] array, ref int index, ByteOrder endianness = ByteOrder.LittleEndian)
{
var decoder = new Utf16.ByteDecoder(endianness);
if (index + 2 > array.Length)
{
throw new ArgumentOutOfRangeException("index", "Need at least 2 bytes to process Utf16");
}
decoder.Process(array[index++]);
var result = decoder.Process(array[index++]);
if (result == null)
{
if (index + 2 > array.Length)
{
throw new ArgumentOutOfRangeException("index", "Need 4 bytes to process Utf16 surrogate pair");
}
decoder.Process(array[index++]);
result = decoder.Process(array[index++]);
if (result == null)
{
throw new RuneException(Utf16.MissingTrailingSurrogateMessage());
}
}
return(new Rune(result.GetValueOrDefault()));
}
private static Rune[] UncheckedToRuneArray(string value, int start, int amount)
{
if (start < 0 || start > value.Length)
{
throw new ArgumentOutOfRangeException("start");
}
if (amount < 0 || start + amount > value.Length)
{
throw new ArgumentOutOfRangeException("amount");
}
var runes = new Rune[amount];
int index = 0;
var decoder = new Utf16.CharDecoder();
bool result = true;
for (int i = start; i < amount; i++)
{
var utf32 = decoder.Process(value[i]);
if (utf32 != null)
{
runes[index++] = (Rune)utf32.GetValueOrDefault();
}
}
if (!result)
{
throw new RuneException(Utf16.MissingTrailingSurrogateMessage());
}
if (index < runes.Length)
{
Array.Resize(ref runes, index);
}
return(runes);
}
private static IEnumerable <Rune> UncheckedToRunes(string value, int start, int amount)
{
if (start < 0 || start > value.Length)
{
throw new ArgumentOutOfRangeException("start");
}
if (amount < 0 || start + amount > value.Length)
{
throw new ArgumentOutOfRangeException("amount");
}
var runes = new Rune[amount];
var decoder = new Utf16.CharDecoder();
bool result = true;
for (int i = start; i < amount; i++)
{
var utf32 = decoder.Process(value[i]);
if (utf32 != null)
{
yield return((Rune)utf32.GetValueOrDefault());
}
}
if (!result)
{
throw new RuneException(Utf16.MissingTrailingSurrogateMessage());
}
}
// char... -> Rune...
public static IEnumerable <Rune> ToRunes(this IEnumerable <char> chars)
{
var decoder = new Utf16.CharDecoder();
return(DecodeValues(chars, decoder, Utf16.MissingTrailingSurrogateMessage()));
}