R/is_prefixed.R

In labelled: Manipulating Labelled Data

#' Check if a factor is prefixed
#' @param x a factor
#' @export
is_prefixed <- function(x) {
  if (!is.factor(x))
    stop("is_prefixed should be used only with a factor.")
  l <- .get_prefixes.factor(x)
  all(!is.na(l$code)) && all(!is.na(l$code)) && !any(duplicated(l$code))
}


# return a tibble with levels, code and label
# if the factor is prefixed, otherwise NA
.get_prefixes.factor <- function(x) {
  dplyr::tibble(levels = levels(x)) %>%
    tidyr::extract(
      "levels",
      c("code", "label"),
      "^\\[(.+)\\]\\s(.+)$",
      remove = FALSE
    )
}