internal static Utf8String CreateFromRune(Rune value)
{
Utf8String newString = FastAllocate(value.Utf8SequenceLength);
int bytesWritten = value.EncodeToUtf8(new Span <byte>(ref newString.DangerousGetMutableReference(), newString.Length));
Debug.Assert(bytesWritten == value.Utf8SequenceLength);
return(newString);
}
// Ordinal search
public bool StartsWith(Rune value)
{
// TODO_UTF8STRING: This should be split into two methods:
// One which operates on a single-byte (ASCII) search value,
// the other which operates on a multi-byte (non-ASCII) search value.
Span <byte> runeBytes = stackalloc byte[Utf8Utility.MaxBytesPerScalar];
int runeBytesWritten = value.EncodeToUtf8(runeBytes);
return(this.AsBytes().StartsWith(runeBytes.Slice(0, runeBytesWritten)));
}
// Ordinal search
public int IndexOf(Rune value)
{
// TODO_UTF8STRING: This should be split into two methods:
// One which operates on a single-byte (ASCII) search value,
// the other which operates on a multi-byte (non-ASCII) search value.
Span <byte> runeBytes = stackalloc byte[Utf8Utility.MaxBytesPerScalar];
int runeBytesWritten = value.EncodeToUtf8(runeBytes);
return(SpanHelpers.IndexOf(
ref DangerousGetMutableReference(), Length,
ref MemoryMarshal.GetReference(runeBytes), runeBytesWritten));
}
/// <summary>
/// Returns a value stating whether the current <see cref="Utf8String"/> instance contains
/// the specified <see cref="Rune"/>. An ordinal comparison is used.
/// </summary>
public bool Contains(Rune value)
{
// TODO_UTF8STRING: This should be split into two methods:
// One which operates on a single-byte (ASCII) search value,
// the other which operates on a multi-byte (non-ASCII) search value.
Span <byte> runeBytes = stackalloc byte[Utf8Utility.MaxBytesPerScalar];
int runeBytesWritten = value.EncodeToUtf8(runeBytes);
#if SYSTEM_PRIVATE_CORELIB
return(SpanHelpers.IndexOf(
ref DangerousGetMutableReference(), Length,
ref MemoryMarshal.GetReference(runeBytes), runeBytesWritten) >= 0);
#else
return(GetSpan()
.IndexOf(runeBytes.Slice(0, runeBytesWritten)) >= 0);
#endif
}
internal static Utf8String CreateFromRune(Rune value)
{
// Can skip zero-init since we're going to populate the entire buffer.
Utf8String newString = FastAllocateSkipZeroInit(value.Utf8SequenceLength);
if (value.IsAscii)
{
// Fast path: If an ASCII value, just allocate the one-byte string and fill in the single byte contents.
newString.DangerousGetMutableReference() = (byte)value.Value;
return(newString);
}
else
{
// Slow path: If not ASCII, allocate a string of the appropriate length and fill in the multi-byte contents.
int bytesWritten = value.EncodeToUtf8(newString.DangerousGetMutableSpan());
Debug.Assert(newString.Length == bytesWritten);
return(newString);
}
}
