R/otype.r

In hadley/pryr: Tools for Computing on the Language

#' Determine object type.
#'
#' @details
#' Figure out which object system an object belongs to:
#'
#' \itemize{
#'   \item base: no class attribute
#'   \item S3: class attribute, but not S4
#'   \item S4: \code{\link{isS4}}, but not RC
#'   \item RC: inherits from "refClass"
#' }
#'
#' @param x object to determine type of
#' @export
#' @family object inspection
#' @examples
#' otype(data.frame())
#' otype(1:10)
otype <- function(x) {
  if (!is.object(x)) {
    "base"
  } else if (!isS4(x)) {
    "S3"
  } else if (!is(x, "refClass")) {
    "S4"
  } else {
    "RC"
  }
}