internal static Set UniteFiniteSetAndSet(FiniteSet finite, Set set)
{
if (set is FiniteSet another)
{
return(FiniteSet.Unite(finite, another));
}
var sb = new FiniteSetBuilder();
if (set is Interval(var left, var leftClosed, var right, var rightClosed) inter)
{
var newLeftClosed = leftClosed;
var newRightClosed = rightClosed;
foreach (var el in finite)
{
if (!set.TryContains(el, out var contains) || !contains)
{
if (el == left)
{
newLeftClosed = true;
}
else if (el == right)
{
newRightClosed = true;
}
else
{
sb.Add(el);
}
}
}
set = inter.New(left, newLeftClosed, right, newRightClosed);
}
internal static Set IntersectFiniteSetAndSet(FiniteSet finite, Set set)
{
if (set is FiniteSet another)
{
return(FiniteSet.Intersect(finite, another));
}
var fsb = new FiniteSetBuilder();
var amb = new FiniteSetBuilder();
foreach (var elem in finite)
{
if (!set.TryContains(elem, out var contains))
{
amb.Add(elem);
}
else if (contains)
{
fsb.Add(elem);
}
}
return(amb.IsEmpty ? fsb.ToFiniteSet() : amb.ToFiniteSet().Unite(fsb.ToFiniteSet()));
}