Having separate options use_timestamps = T/F and overwrite = T/F is confusing. This would be much clearer if overwrite simply took one of three values: TRUE, FALSE, or use_timestamps, since the latter is really an intermediate overwrite rule (i.e. always overwrite, never overwrite, or overwrite only older timestamps).
Of course this means mixing logical and character input, but I guess that's okay.
Having separate options
use_timestamps = T/Fandoverwrite = T/Fis confusing. This would be much clearer ifoverwritesimply took one of three values:TRUE,FALSE, oruse_timestamps, since the latter is really an intermediate overwrite rule (i.e. always overwrite, never overwrite, or overwrite only older timestamps).Of course this means mixing logical and character input, but I guess that's okay.