internal static ValueGetter <VBuffer <TDst> > GetVecGetterAs <TDst>(PrimitiveDataViewType typeDst, SlotCursor cursor)
{
Contracts.CheckValue(typeDst, nameof(typeDst));
Contracts.CheckParam(typeDst.RawType == typeof(TDst), nameof(typeDst));
var typeSrc = cursor.GetSlotType();
Func <VectorType, PrimitiveDataViewType, GetterFactory, ValueGetter <VBuffer <TDst> > > del = GetVecGetterAsCore <int, TDst>;
var methodInfo = del.GetMethodInfo().GetGenericMethodDefinition().MakeGenericMethod(typeSrc.ItemType.RawType, typeof(TDst));
return((ValueGetter <VBuffer <TDst> >)methodInfo.Invoke(null, new object[] { typeSrc, typeDst, GetterFactory.Create(cursor) }));
}
internal static ValueGetter <VBuffer <Single> > GetLabelGetter(SlotCursor cursor)
{
var type = cursor.GetSlotType().ItemType;
if (type == NumberDataViewType.Single)
{
return(cursor.GetGetter <Single>());
}
if (type == NumberDataViewType.Double || type is BooleanDataViewType)
{
return(GetVecGetterAs <Single>(NumberDataViewType.Single, cursor));
}
if (!(type is KeyType keyType))
{
throw Contracts.Except("Only floating point number, boolean, and key type values can be used as label.");
}
Contracts.Assert(TestGetLabelGetter(type) == null);
ulong keyMax = (ulong)keyType.Count;
if (keyMax == 0)
{
keyMax = ulong.MaxValue;
}
var getSrc = RowCursorUtils.GetVecGetterAs <ulong>(NumberDataViewType.UInt64, cursor);
VBuffer <ulong> src = default(VBuffer <ulong>);
return
((ref VBuffer <Single> dst) =>
{
getSrc(ref src);
// Unfortunately defaults in one to not translate to defaults of the other,
// so this will not be sparsity preserving. Assume a dense output.
var editor = VBufferEditor.Create(ref dst, src.Length);
foreach (var kv in src.Items(all: true))
{
if (0 < kv.Value && kv.Value <= keyMax)
{
editor.Values[kv.Key] = kv.Value - 1;
}
else
{
editor.Values[kv.Key] = Single.NaN;
}
}
dst = editor.Commit();
});
}