public Object getValueAndEvaluateInputExpression(VectorPTFEvaluatorBase evaluator, int row,
      int col) throws HiveException {
    RowPositionInBatch rp = getPosition(row);
    BufferedVectorizedRowBatch batch = bufferedBatches.get(rp.batchIndex);
    if (!batch.isInputExpressionEvaluated) {
      evaluator.evaluateInputExpr(batch);
    }
    return getValueFromBatch(batch, col, rp.rowIndexInBatch);
  }
Returns the value at row/col. Row index is absolute inside a PTF partition, col should point to
the remapped column index according to bufferedColumnMap. The input expressions of the
evaluators are already aware of this remapped column as they are changed in
VectorPTFOperator.initBufferedColumns.
@param row
@param col
@return
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/ptf/VectorPTFGroupBatches.java