group-indices.R

#' Group id.
#'
#' Generate a unique id for each group
#'
#' @seealso \code{\link{group_by}}
#' @param .data a tbl
#' @inheritParams group_by
#' @inheritParams filter
#' @export
#' @examples
#' group_indices(mtcars, cyl)
group_indices <- function(.data, ...) {
  group_indices_(.data, .dots = lazyeval::lazy_dots(...) )
}

#' @export
#' @rdname group_indices
group_indices_ <- function(.data, ..., .dots) {
  UseMethod("group_indices_")
}

#' @export
group_indices_.data.frame <- function(.data, ..., .dots ){
  groups <- group_by_prepare(.data, .dots = .dots )
  grouped_indices_impl(groups$data, groups$groups)
}

#' @export
group_indices_.grouped_df <- function(.data, ..., .dots ){
  if( length(list(...)) || ( ! missing(.dots) && length(.dots) ) ){
    warning( "group_indices_.grouped_df ignores extra arguments" )
  }
  grouped_indices_grouped_df_impl(.data)
}