Proposal for a new `label_fun` argument for split functions

Hi @gmbecker ,

I’d like to propose adding a new argument (say, label_fun) to split_rows*() / split_cols*().

The idea would be to allow users to provide a function that changes/formats the levels of the split variable. For example, suppose we have a SEX variable in the dataset with levels MALE and FEMALE, but we want the split labels to appear as Male and Female instead.

With this argument, I could simply specify:

label_fun = junco::string_to_title

and that would be it. I think transformations like string_to_title() are very common when formatting labels, so this would be a convenient way to handle this without having to modify the dataset itself.

Please consider it. Thanks!

Locate the split_rows*() and split_cols*() entry points first, then trace how split-variable levels become displayed labels. The proposal is complete when a label_fun argument can format those labels, including MALE/FEMALE as Male/Female, without modifying the source dataset.