R/type-unspecified.R

In vctrs: Vector Helpers

#' A 1d vector of unspecified type
#'
#' This is a [partial type][new_partial] used to represent logical vectors
#' that only contain `NA`. These require special handling because we want to
#' allow `NA` to specify missingness without requiring a type.
#'
#' @keywords internal
#' @param n Length of vector
#' @export
#' @examples
#' vec_ptype_show()
#' vec_ptype_show(NA)
#'
#' vec_c(NA, factor("x"))
#' vec_c(NA, Sys.Date())
#' vec_c(NA, Sys.time())
#' vec_c(NA, list(1:3, 4:5))
unspecified <- function(n = 0) {
  .Call(vctrs_unspecified, n)
}

#' @export
`[.vctrs_unspecified` <- function(x, i, ...) {
  unspecified(length(NextMethod()))
}

#' @export
print.vctrs_unspecified <- function(x, ...) {
  cat("<unspecified> [", length(x), "]\n", sep = "")
}

#' @export
vec_ptype_abbr.vctrs_unspecified <- function(x, ...) {
  "???"
}

is_unspecified <- function(x) {
  .Call(vctrs_is_unspecified, x)
}

ununspecify <- function(x) {
  if (is_unspecified(x)) {
    new_logical(length(x))
  } else {
    x
  }
}