Internal function that replaces regex matches with underscores
preprocess_internal(string, sep_in)A character containing the parsed string.
A string.
(short for separator input) A regex supplied as a character (if not NULL), which will be wrapped internally
into stringr::regex(). All matches will be replaced by underscores (additionally to
"_" and " ", for which this is always true). Underscores can later turned into another separator via postprocess.
Malte Grosser, malte.grosser@gmail.com