@Override
      public Object writeValue(ColumnVector column, int row)
          throws HiveException {
        final ListColumnVector listColVector = (ListColumnVector) column;
        final SettableListObjectInspector listOI =
            (SettableListObjectInspector) this.objectInspector;
        final List value = (List) vectorExtractRow.extractRowColumn(listColVector,
            listTypeInfo, listOI, row);
        if (value == null) {
          return null;
        }

        listOI.resize(obj, value.size());
        for (int i = 0; i < value.size(); i++) {
          listOI.set(obj, i, value.get(i));
        }
        return obj;
      }
Compiles the appropriate vector expression writers based on a struct object
inspector.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/VectorExpressionWriterFactory.java