static public void Test()
{
BitVector S1 = 0b0011_0010;
BitVector S2 = 0b0100_0011;
Debug.Assert(SetOp.Union(S1, S2) == 0b0111_0011);
Debug.Assert(SetOp.Union(S1, S2) == SetOp.Union(S2, S1));
Debug.Assert(SetOp.Intersect(S1, S2) == 0b0000_0010);
Debug.Assert(SetOp.Intersect(S1, S2) == SetOp.Intersect(S2, S1));
Debug.Assert(SetOp.Substract(S1, S2) == 0b0011_0000);
Debug.Assert(SetOp.Substract(S2, S1) == 0b0100_0001);
Debug.Assert(SetOp.CountSetBits(S1) == 3);
Debug.Assert(SetOp.MinTableIndex(S1) == 1);
Debug.Assert(SetOp.MinTableIndex(S2) == 0);
Debug.Assert(SetOp.OrderBeforeSet(3) == 15);
var l = SetOp.TablesAscending(S2).ToList();
Debug.Assert(l.SequenceEqual(new List <int>()
{
0, 1, 6
}));
l = SetOp.TablesDescending(S2).ToList();
Debug.Assert(l.SequenceEqual(new List <int>()
{
6, 1, 0
}));
}
IEnumerable <BitVector> enumerateCsgRecursive(JoinGraph graph, BitVector S, BitVector X)
{
// N = neighbour(S) \ X
BitVector N = SetOp.Substract(graph.NeighboursExcluding(S), X);
// Console.WriteLine("N: " + BitHelper.ToString(N));
// for all non-empty S' subsetof(N), emit (S union S')
if (N != SetOp.EmptySet)
{
VancePartition partitioner = new VancePartition(N);
foreach (var S_prime in partitioner.Next(true))
{
yield return(SetOp.Union(S, S_prime));
}
// for all non-empty S' subsetof(N), recursively invoke (graph, (S union S'), (X union N))
partitioner = new VancePartition(N);
foreach (var S_prime in partitioner.Next(true))
{
foreach (var v in enumerateCsgRecursive(graph,
SetOp.Union(S, S_prime), SetOp.Union(X, N)))
{
yield return(v);
}
}
}
}
IEnumerable <BitVector> enumerateCmp(JoinGraph graph, BitVector S1)
{
int ntables = graph.vertices_.Count;
Debug.Assert(S1 != SetOp.EmptySet);
// min(S1) := min({i|v_i \in S1})
int minS1 = SetOp.MinTableIndex(S1);
// B_i(W) := {vj |v_j \in W, j <= i}
// X = union (B_min(S1), S)
BitVector BminS1 = SetOp.OrderBeforeSet(minS1);
BitVector X = SetOp.Union(BminS1, S1);
// N = neighbour(S1) \ X
BitVector N = SetOp.Substract(graph.NeighboursExcluding(S1), X);
// for all(vi 2 N by descending i)
foreach (int vi in SetOp.TablesDescending(N))
{
// emit {v_i}
BitVector VI = SetOp.SingletonSet(vi);
yield return(VI);
// recursively invoke enumerateCmp(graph, {v_i}, X union (B_i intersect N))
BitVector Bi = SetOp.OrderBeforeSet(vi);
BitVector BiN = SetOp.Intersect(Bi, N);
foreach (var csg in enumerateCsgRecursive(graph,
VI, SetOp.Union(X, BiN)))
{
yield return(csg);
}
}
}
internal CsgCmpPair(JoinGraph graph, BitVector S1, BitVector S2)
{
S1_ = S1; S2_ = S2;
S_ = SetOp.Union(S1, S2);
Verify(graph);
}