R/precondition.R

Defines functions ensure_directory require_directory_exists require_file_exists ensure_not_null ensure_not_na

ensure_not_na <- function(object) {
  if (any(is.na(object))) {
    stopf(
      "'%s' %s",
      deparse(substitute(object)),
      if (length(object) > 1) "contains NA values" else "is NA"
    )
  }

  object
}

ensure_not_null <- function(object) {
  object %||% stop(sprintf("'%s' is NULL", deparse(substitute(object))))
}

#' Enforce Specific Structure for R Objects
#'
#' These routines are useful when preparing to pass objects to
#' a Spark routine, as it is often necessary to ensure certain
#' parameters are scalar integers, or scalar doubles, and so on.
#'
#' @param object An \R object.
#' @param allow.na Are \code{NA} values permitted for this object?
#' @param allow.null Are \code{NULL} values permitted for this object?
#' @param default If \code{object} is \code{NULL}, what value should
#'   be used in its place? If \code{default} is specified, \code{allow.null}
#'   is ignored (and assumed to be \code{TRUE}).
#'
#' @name ensure
#' @rdname ensure
NULL

require_file_exists <- function(path, fmt = NULL) {
  fmt <- fmt %||% "no file at path '%s'"
  if (!file.exists(path)) stopf(fmt, path)
  path
}

require_directory_exists <- function(path, fmt = NULL) {
  fmt <- fmt %||% "no file at path '%s'"
  require_file_exists(path)
  info <- file.info(path)
  if (!isTRUE(info$isdir)) stopf(fmt, path)
  path
}

ensure_directory <- function(path) {
  if (file.exists(path)) {
    info <- file.info(path)
    if (isTRUE(info$isdir)) {
      return(path)
    }
    stopf("path '%s' exists but is not a directory", path)
  }

  if (!dir.create(path, recursive = TRUE)) {
    stopf("failed to create directory at path '%s'", path)
  }

  invisible(path)
}

Try the sparklyr package in your browser

Any scripts or data that you put into this service are public.

sparklyr documentation built on Jan. 8, 2022, 5:06 p.m.