How to access additional information from the parser in my enumerator?

Question

I extended the parser so that it accepts a range with two arguments as integers in the from clause, i. e.,

SELECT *
FROM a RANGE x AND y

where x, y are SqlNumericLiterals and range is a tableRef operator.

However, I'm clueless how to access this additional information in my Enumerator class. How can I do that?