public override int Compare(T x, T y)
{
TKey xKey = _keySelector(x);
TKey yKey = _keySelector(y);
return(NullFilter.Filter(xKey, yKey) ?? Comparer.Compare(x, y));
}
public static IComparer <T> GetComparer(IComparer <T> comparer, Func <T, TKey> keySelector, bool nullsFirst)
{
NullFilter <TKey> filter = NullFilterFactory.GetNullFilter <TKey>(nullsFirst);
if (filter == null)
{
return(comparer);
}
return(new KeyedNullPlacementComparer <T, TKey>(comparer, keySelector, filter));
}
public static IComparer <T> GetComparer(IComparer <T> comparer, bool nullsFirst)
{
NullFilter <T> filter = NullFilterFactory.GetNullFilter <T>(nullsFirst);
if (filter == null)
{
return(comparer);
}
return(new UnkeyedNullPlacementComparer <T>(comparer, filter));
}
internal KeyedNullPlacementComparer(IComparer <T> comparer, Func <T, TKey> keySelector, NullFilter <TKey> filter)
: base(comparer, filter)
{
_keySelector = keySelector;
}
public override int Compare(T x, T y)
{
return(NullFilter.Filter(x, y) ?? Comparer.Compare(x, y));
}
internal UnkeyedNullPlacementComparer(IComparer <T> comparer, NullFilter <T> filter)
: base(comparer, filter)
{
}
protected NullPlacementComparer(IComparer <T> comparer, NullFilter <TCompared> filter)
{
Comparer = comparer;
NullFilter = filter;
}