R/Existy.R

In functools: Functional Programming in R

#' Existy
#'
#' \code{Existy()} returns TRUE or FALSE if an object exists or not.
#' An object exists if it is not NULL or NA.
#'
#' @param .x an object.
#' @return a logical value.
#' @family predicate functions
#' @examples
#' # Some examples
#' Existy(4) # TRUE
#' Existy("foo") # TRUE
#' Existy(NULL) # FALSE
#' Existy(NA) # FALSE
#'
#' # Works with lists
#' Existy(list(4, "foo", NULL, NA)) # TRUE
#' Existy(list(4, "foo")) # TRUE
#' Existy(list(NULL, NA)) # TRUE
#' Existy(list(NULL)) # TRUE
#' Existy(list(NA)) # FALSE
#'
#' # Works with applying over lists
#' lapply(list(4, "foo", NULL, NA), Existy) # TRUE, TRUE, FALSE, FALSE
#' @export
Existy <- function(.x) {
  return(!is.null(.x) && !is.na(.x))
}