Currently `control()` coerces `<NA>` to `"NA"` and tries to find it in the thesaurus. It should instead ensure NAs in x are always returned as NAs. Maybe we should warn if `x` contains NAs, though?
Currently
control()coerces<NA>to"NA"and tries to find it in the thesaurus. It should instead ensure NAs in x are always returned as NAs.Maybe we should warn if
xcontains NAs, though?