Consider a filter_for_linked function

[boshek]

@stephhazlitt

Thinking about in addition to the add_linked_status function we have something that wraps:

filter(grepl("s", studyid))

Name ideas:

drop_unlinked?

[stephhazlitt]

Or filter_linked()?

[boshek]

The amazing part now is that we can have methods for Data.Frames and for Arrow Datasets given arrow 5.0.0 now has the ability to do string processing before the collect step.