@subset won't work if base class is not @pcc_set

[rohan-achar]

There are conflicts in Meta class that has to be fixed. Requires deep thought.

[arthur00]

Is this a real issue? Can't we just define that subsets only apply to pcc_sets, and check for that? If a non pcc_set is passed, we just thrown an exception. or do you mean that subset of subset or subset of join does not work?

[rohan-achar]

no the first case.

We can define subset to only work on pcc types, but for cases where dataframe is used, but not in spacetime, @subset cannot be defined over a normal class, it has to be declared only over a pcc_set. Tedious. But it's such a small issue, that even I'm not sure it needs to be an issue.

[arthur00]

I think as long as we document it it's not an issue. (it's a feature! ha-ha)
We just need to be sure that appropriate exception is thrown so the user knows what went wrong and why it's his fault (for using subset on a non-pcc_set). If that is done, this issue can be closed.