export additional helper functions

[topepo]

format_selectors and format_ch_vec

[khailper]

Edit: Given the documentation these functions will need, I'm withdrawing my claim on this issue so someone with a better understanding of recipes can tackle it.

I'll claim this one.

[khailper]

format_selectors has a wdth parameter, but format_ch_vec uses width for the same purpose. Should I edit the source code to make the variable names consistent?

[DavisVaughan]

For the issue solver:

• Unify the argument names: wdth -> width
• Remove the ... from format_selectors()
• Can the name of format_ch_vec() be more informative?
• These changes mean you will also have to modify the internal usage of these functions to make sure they are still working correctly

[topepo]

@khailper If you want, go ahead and export them then I can edit the PR with the documentation (after I get out of a meeting in about an hour).

[khailper]

• Can the name of format_ch_vec() be more informative?

@DavisVaughan maybe format_chr_vec() as an alternative? (in the vein of purrr::map_chr())

[khailper]

I'm going to submit the PR without changing the name of format_ch_vec(), but if we can converge on a new name, then I'd be happy to update the relevant internal usage.