public static CompactSketch aNotB()

in src/main/java/org/apache/datasketches/tuple/AnotB.java [315:380]
60 lines of code
11 McCabe index (conditional complexity)

  public static <S extends Summary> CompactSketch<S> aNotB(
      final Sketch<S> skA,
      final Sketch<S> skB) {
    if (skA == null || skB == null) {
      throw new SketchesArgumentException("Neither argument may be null for this stateless operation.");
    }

    final long thetaLongA = skA.getThetaLong();
    final int countA = skA.getRetainedEntries();
    final boolean emptyA = skA.isEmpty();

    final long thetaLongB = skB.getThetaLong();
    final int countB = skB.getRetainedEntries();
    final boolean emptyB = skB.isEmpty();

    final int id =
        SetOperationCornerCases.createCornerCaseId(thetaLongA, countA, emptyA, thetaLongB, countB, emptyB);
    final CornerCase cCase = CornerCase.caseIdToCornerCase(id);
    final AnotbAction anotbAction = cCase.getAnotbAction();

    CompactSketch<S> result = null;

    switch (anotbAction) {
      case EMPTY_1_0_T: {
        result = new CompactSketch<>(null, null, Long.MAX_VALUE, true);
        break;
      }
      case DEGEN_MIN_0_F: {
        final long thetaLong = min(thetaLongA, thetaLongB);
        result = new CompactSketch<>(null, null, thetaLong, false);
        break;
      }
      case DEGEN_THA_0_F: {
        result = new CompactSketch<>(null, null, thetaLongA, false);
        break;
      }
      case TRIM_A: {
        final DataArrays<S> daA = getCopyOfDataArraysTuple(skA);
        final long[] hashArrA = daA.hashArr;
        final S[] summaryArrA = daA.summaryArr;
        final long minThetaLong =  min(thetaLongA, thetaLongB);
        final DataArrays<S> da = trimAndCopyDataArrays(hashArrA, summaryArrA, minThetaLong, false);
        result = new CompactSketch<>(da.hashArr, da.summaryArr, minThetaLong, skA.empty_);
        break;
      }
      case SKETCH_A: {
        final DataArrays<S> daA = getCopyOfDataArraysTuple(skA);
        result = new CompactSketch<>(daA.hashArr, daA.summaryArr, thetaLongA, skA.empty_);
        break;
      }
      case FULL_ANOTB: { //both A and B should have valid entries.
        final DataArrays<S> daA = getCopyOfDataArraysTuple(skA);
        final long minThetaLong = min(thetaLongA, thetaLongB);
        final DataArrays<S> daR =
            getCopyOfResultArraysTuple(minThetaLong, daA.hashArr.length, daA.hashArr, daA.summaryArr, skB);
        final int countR = (daR.hashArr == null) ? 0 : daR.hashArr.length;
        if (countR == 0) {
          result = new CompactSketch<>(null, null, minThetaLong, minThetaLong == Long.MAX_VALUE);
        } else {
          result = new CompactSketch<>(daR.hashArr, daR.summaryArr, minThetaLong, false);
        }
      }
      //default: not possible
    }
    return result;
  }