R/null-and-default.R

In tidymodels/broom: Convert Statistical Objects into Tidy Tibbles

#' Tidiers for NULL inputs
#'
#' `tidy(NULL)`, `glance(NULL)` and `augment(NULL)` all return an empty
#' [tibble::tibble]. This empty tibble can be treated a tibble with zero
#' rows, making it convenient to combine with other tibbles using
#' functions like [purrr::map_df()] on lists of potentially `NULL` objects.
#'
#' @param x The value `NULL`.
#' @param ... Additional arguments (not used).
#'
#' @return An empty [tibble::tibble].
#'
#' @name null_tidiers
#' @export
#' @seealso [tibble::tibble]
tidy.NULL <- function(x, ...) {
  tibble()
}

#' @rdname null_tidiers
#' @export
glance.NULL <- function(x, ...) tibble()

#' @rdname null_tidiers
#' @export
augment.NULL <- function(x, ...) tibble()



#' @export
tidy.default <- function(x, ...) {
  cli::cli_abort("No {.fn tidy} method for objects of class {.cls {class(x)}}.")
}

#' @export
glance.default <- function(x, ...) {
  cli::cli_abort("No {.fn glance} method for objects of class {.cls {class(x)}}.")
}

#' @export
augment.default <- function(x, ...) {
  cli::cli_abort("No {.fn augment} method for objects of class {.cls {class(x)}}.")
}