This function is intended for use as a preprocessing
component in make_split_fun, and should not be called
directly by end users.
Arguments
- df
data.frame. The incoming data corresponding with the parent facet
- spl
Split.
- ...
dots. This is used internally to pass parameters.
See also
make_split_fun
Other make_custom_split:
add_combo_facet(),
make_split_fun(),
make_split_result(),
trim_levels_in_facets()