What happened to Active Record ar_select?

Hello;

I am upgrading a site from CI 2.0 to CI 3.1.3 and have come upon some code that accesses the CI AR internals called ar_select, ar_from, ar_join etc.  These seem to be completely gone in CI 3.  Does anyone know of a way to simulate them?  I know that I can use the (new) get_compiled_query() and then parse the SQL but I am hoping there is an easier way.

Thanks in advance,
=dave=