private void DropNAs <TDst>(ref VBuffer <TDst> src, ref VBuffer <TDst> dst, InPredicate <TDst> isNA)
{
Host.AssertValue(isNA);
var srcValues = src.GetValues();
int newCount = 0;
for (int i = 0; i < srcValues.Length; i++)
{
if (!isNA(in srcValues[i]))
{
newCount++;
}
}
Host.Assert(newCount <= srcValues.Length);
if (newCount == 0)
{
VBufferUtils.Resize(ref dst, src.Length - srcValues.Length, 0);
return;
}
if (newCount == srcValues.Length)
{
Utils.Swap(ref src, ref dst);
return;
}
int iDst = 0;
if (src.IsDense)
{
var editor = VBufferEditor.Create(ref dst, newCount);
for (int i = 0; i < srcValues.Length; i++)
{
if (!isNA(in srcValues[i]))
{
editor.Values[iDst] = srcValues[i];
iDst++;
}
}
Host.Assert(iDst == newCount);
dst = editor.Commit();
}
else
{
var newLength = src.Length - srcValues.Length - newCount;
var editor = VBufferEditor.Create(ref dst, newLength, newCount);
var srcIndices = src.GetIndices();
int offset = 0;
for (int i = 0; i < srcValues.Length; i++)
{
if (!isNA(in srcValues[i]))
{
editor.Values[iDst] = srcValues[i];
editor.Indices[iDst] = srcIndices[i] - offset;
iDst++;
}
