R/as_duckplyr_df.R

In duckplyr: A 'DuckDB'-Backed Version of 'dplyr'

#' Convert to a duckplyr data frame
#'
#' @description
#' These functions convert a data-frame-like input to an object of class `"duckpylr_df"`.
#' For such objects,
#' dplyr verbs such as [mutate()], [select()] or [filter()]  will attempt to use DuckDB.
#' If this is not possible, the original dplyr implementation is used.
#'
#' `as_duckplyr_df()` requires the input to be a plain data frame or a tibble,
#' and will fail for any other classes, including subclasses of `"data.frame"` or `"tbl_df"`.
#' This behavior is likely to change, do not rely on it.
#'
#' @details
#' Set the `DUCKPLYR_FALLBACK_INFO` and `DUCKPLYR_FORCE` environment variables
#' for more control over the behavior, see [config] for more details.
#'
#' @param .data data frame or tibble to transform
#'
#' @return For `as_duckplyr_df()`, an object of class `"duckplyr_df"`,
#'   inheriting from the classes of the `.data` argument.
#'
#' @export
#' @examples
#' tibble(a = 1:3) %>%
#'   mutate(b = a + 1)
#'
#' tibble(a = 1:3) %>%
#'   as_duckplyr_df() %>%
#'   mutate(b = a + 1)
as_duckplyr_df <- function(.data) {
  if (inherits(.data, "duckplyr_df")) {
    return(.data)
  }

  if (!identical(class(.data), "data.frame") && !identical(class(.data), c("tbl_df", "tbl", "data.frame"))) {
    cli::cli_abort("Must pass a plain data frame or a tibble to `as_duckplyr_df()`.")
  }

  if (anyNA(names(.data)) || any(names(.data) == "")) {
    cli::cli_abort("Missing or empty names not allowed.")
  }

  class(.data) <- c("duckplyr_df", class(.data))
  .data
}