private static bool InterfaceCharMoveNext(ref RuneEnumerator e)
{
if (e.State is IEnumerator <char> enumerator)
{
if (!enumerator.MoveNext())
{
return(false);
}
char highSurrogate = enumerator.Current;
if (Rune.TryCreate(highSurrogate, out Rune rune))
{
e.Current = rune;
return(true);
}
if (!enumerator.MoveNext())
{
return(false);
}
char lowSurrogate = enumerator.Current;
if (Rune.TryCreate(highSurrogate, lowSurrogate, out rune))
{
e.Current = rune;
return(true);
}
}
return(false);
}
private static bool StringMoveNext(ref RuneEnumerator e)
{
if (e._stringEnumerator.MoveNext())
{
e.Current = e._stringEnumerator.Current;
return(true);
}
return(false);
}
private static bool InterfaceRuneMoveNext(ref RuneEnumerator e)
{
if (e.State is IEnumerator <Rune> enumerator && enumerator.MoveNext())
{
e.Current = enumerator.Current;
return(true);
}
return(false);
}
private static bool Utf8MoveNext(ref RuneEnumerator e)
{
if (e._utf8Enumerator.MoveNext())
{
e.Current = e._utf8Enumerator.Current;
return(true);
}
return(false);
}
public readonly override string ToString()
{
RuneEnumerator runes = this;
StringBuilder builder = new();
Span <char> buffer = stackalloc char[4];
foreach (Rune rune in runes)
{
int encoded = rune.EncodeToUtf16(buffer);
builder.Append(buffer.Slice(0, encoded));
}
return(builder.ToString());
}
private static bool BuilderMoveNext(ref RuneEnumerator e)
{
TryReturnFromChunk:
if (e._spanEnumerator.MoveNext())
{
e.Current = e._spanEnumerator.Current;
return(true);
}
if (e._builderEnumerator.MoveNext())
{
var chunkSpan = e._builderEnumerator.Current.Span;
e._spanEnumerator = chunkSpan.EnumerateRunes();
goto TryReturnFromChunk;
}
return(false);
}
public Utf8Enumerator(RuneEnumerator runes) : this()
{
_runeEnumerator = runes;
}
public static Utf8Enumerator GetUtf8Enumerator(this RuneEnumerator runes)
{
return(new Utf8Enumerator(runes));
}