/** Collect documents from a bitset. */
private List<Document> collectDocuments(List<Document> l, BitSet bitset) {
if (l == null) {
l = Lists.newArrayListWithCapacity((int) bitset.cardinality());
}
final BitSetIterator i = bitset.iterator();
for (int d = i.nextSetBit(); d >= 0; d = i.nextSetBit()) {
l.add(documents.get(d));
}
return l;
}
@Test
public void testCardinality() {
BitSet bitSet = new BitSet(NUM_BITS);
assertEquals(0, bitSet.cardinality());
bitSet.set(0);
assertEquals(1, bitSet.cardinality());
bitSet.set(0);
assertEquals(1, bitSet.cardinality());
bitSet.set(1);
assertEquals(2, bitSet.cardinality());
bitSet.set(63);
assertEquals(3, bitSet.cardinality());
bitSet.set(64);
assertEquals(4, bitSet.cardinality());
bitSet.set(NUM_BITS - 1);
assertEquals(5, bitSet.cardinality());
bitSet.clear(0);
assertEquals(4, bitSet.cardinality());
}
