R/rrroomba.R

In ropenscilabs/roomba: Tidy up nested list hairballs

#' Roomba
#'
#' @description Tidy your nested list
#' @param inp List to tidy
#' @param cols Columns to keep
#' @param default Replacement for NULL values. Defaults to NA.
#' @param keep Should all or any data be kept?
#'
#' @importFrom magrittr %>%
#' @export
#'
#' @examples
#'
#' simple %>% roomba(cols = c("name", "goodstuff"), keep = any)
#' simple %>% roomba(cols = c("name", "goodstuff"), keep = any)
roomba <- function(inp, cols = NULL, default = NA,
                    keep = all) {

  assertthat::assert_that(length(inp) > 0,
                          msg = "Input is of length 0.")

  assertthat::assert_that(!is.null(cols),
                          msg = "cols must be non-NULL.")

  keep <- match.fun(keep)

  inp_clean <- inp %>%
    replace_null(replacement = default)
  # -- Message that NULLs were replaced with NAs?

  has_good_stuff <- function(data, cols) {
    keep(purrr::map_lgl(cols, ~ length(data[[.x]]) > 0))
  }

  indices <-
    dfs_idx(inp_clean, ~ has_good_stuff(data = .x, cols = cols))

  out <- indices %>% purrr::map(
    function(.x) {
      res <- inp[[.x]]
      res[names(res) %in% cols]
    }) %>% replace_null() %>%
  dplyr::bind_rows()

  return(out)
}