The return value is a list, with one element per "name_old" to "name_new" variable combination. If the key has one old variable being recoded 6 ways, that begets 6 elements in the resulting list. Attributes including the classes of the old and new variables are included.
makeKeylist(key, sep = c(character = "\\|", logical = "\\|", integer =
"\\|", factor = "[\\|
A key object or a file name, csv, xlsx or rds.
Separator regular expressions
A list with one element per variable name, along with some attributes like class_old and class_new. The class is set as well, "keylist"