colwise-distinct.R

#' Select distinct rows by a selection of variables
#'
#' These [scoped] variants of [distinct()] extract distinct rows by a
#' selection of variables. Like `distinct()`, you can modify the
#' variables before ordering with [funs()].
#'
#' @inheritParams scoped
#' @export
#' @examples
#' df <- data_frame(x = rep(2:5, each = 2) / 2, y = rep(2:3, each = 4) / 2)
#' df
#' distinct_all(df)
#' distinct_at(df, vars(x,y))
#' distinct_if(df, is.numeric)
#'
#' # You can supply a function that will be applied before extracting the distinct values
#' # The variables of the sorted tibble keep their original values.
#' distinct_all(df, round)
#' arrange_all(df, funs(round(.)))
distinct_all <- function(.tbl, .funs = list(), ...) {
  funs <- manip_all(.tbl, .funs, enquo(.funs), caller_env(), .include_group_vars = TRUE, ...)
  if (!length(funs)) {
    funs <- syms(tbl_vars(.tbl))
  }
  distinct(.tbl, !!!funs)
}
#' @rdname distinct_all
#' @export
distinct_at <- function(.tbl, .vars, .funs = list(), ...) {
  funs <- manip_at(.tbl, .vars, .funs, enquo(.funs), caller_env(), .include_group_vars = TRUE, ...)
  if (!length(funs)) {
    funs <- tbl_at_syms(.tbl, .vars, .include_group_vars = TRUE)
  }
  distinct(.tbl, !!!funs)
}
#' @rdname distinct_all
#' @export
distinct_if <- function(.tbl, .predicate, .funs = list(), ...) {
  funs <- manip_if(.tbl, .predicate, .funs, enquo(.funs), caller_env(), .include_group_vars = TRUE, ...)
  if (!length(funs)) {
    funs <- tbl_if_syms(.tbl, .predicate, .include_group_vars = TRUE)
  }
  distinct(.tbl, !!!funs)
}