@Override
public T eval(List<String> tuple) {
double result = 0;
for (ValueExpression factor : _veList) {
Object currentVal = factor.eval(tuple);
NumericConversion currentType = (NumericConversion) (factor.getType());
result += currentType.toDouble(currentVal);
}
return _wrapper.fromDouble(result);
}
@Override
public T eval(List<String> tuple) {
final ValueExpression firstVE = _veList.get(0);
final Object firstObj = firstVE.eval(tuple);
final NumericConversion firstType = (NumericConversion) firstVE.getType();
double result = firstType.toDouble(firstObj);
for (int i = 1; i < _veList.size(); i++) {
final ValueExpression currentVE = _veList.get(i);
final Object currentObj = currentVE.eval(tuple);
final NumericConversion currentType = (NumericConversion) currentVE.getType();
result -= currentType.toDouble(currentObj);
}
return _wrapper.fromDouble(result);
}
// from Operator
@Override
public List<String> process(List<String> tuple) {
_numTuplesProcessed++;
if (_distinct != null) {
tuple = _distinct.process(tuple);
if (tuple == null) {
return null;
}
}
String tupleHash;
if (_groupByType == GB_PROJECTION) {
tupleHash =
MyUtilities.createHashString(
tuple, _groupByColumns, _groupByProjection.getExpressions(), _map);
} else {
tupleHash = MyUtilities.createHashString(tuple, _groupByColumns, _map);
}
T value = _storage.update(tuple, tupleHash);
String strValue = _wrapper.toString(value);
// propagate further the affected tupleHash-tupleValue pair
List<String> affectedTuple = new ArrayList<String>();
affectedTuple.add(tupleHash);
affectedTuple.add(strValue);
return affectedTuple;
}
@Override
public String evalString(List<String> tuple) {
T result = eval(tuple);
return _wrapper.toString(result);
}