R/is_permutation.R

In jakobbossek/re: Utility Functions Missing in Base R

#' @title
#' Test for permutation
#'
#' @description
#' Check whether \code{x} is a permutation of the multi-set \code{s}.
#'
#' @param x [\code{vector}]\cr
#'   Input vector to be checked.
#' @param s [\code{vector}]\cr
#'   Base set.
#' @examples
#' is_permutation(shuffle(1:10), 1:10)
#' is_permutation(c(2, 1, 4), s = 1:4)
#' @return A scalar logical value.
#' @export
is_permutation = function(x, s) {
  checkmate::assert_vector(x)
  checkmate::assert_vector(s)
  all(x %in% s) & all(s %in% x) & (length(x) == length(s))
}