R/filter_branch.R

In mverse: Tidy Multiverse Analysis Made Simple

#' Create a new filter branch.
#'
#' @examples
#' # Define a filter branch.
#' hurricane_outliers <- filter_branch(
#'   !Name %in% c("Katrina", "Audrey", "Andrew"),
#'   !Name %in% c("Katrina"),
#'   !Name %in% c("Katrina"),
#'   TRUE # include all
#' )
#' # Create a mverse and add the branch.
#' mv <- create_multiverse(hurricane) %>%
#'   add_filter_branch(hurricane_outliers)
#' @param ... branch definition expressions.
#' @param name (optional) Name for the new filter.
#' @return a filter_branch object.
#' @name filter_branch
#' @family filter branch functions
#' @export
filter_branch <- function(..., name = NULL) {
  opts <- rlang::enquos(...)
  branch(opts, name, "filter_branch")
}


#' Add filter branches to a \code{mverse} object.
#'
#' This method adds one or more filter branches to
#' an existing \code{mverse} object. Filter branches
#' are used to define options for conditions
#' for selecting subsets of data rows.
#'
#' @param .mverse a \code{mverse} object.
#' @param ... \code{filter_branch} objects.
#' @examples
#' # Define a filter branch.
#' hurricane_outliers <- filter_branch(
#'   !Name %in% c("Katrina", "Audrey", "Andrew"),
#'   !Name %in% c("Katrina"),
#'   !Name %in% c("Katrina"),
#'   TRUE # include all
#' )
#' # Create a mverse and add the branch.
#' mv <- create_multiverse(hurricane) %>%
#'   add_filter_branch(hurricane_outliers)
#' @return The resulting \code{mverse} object.
#' @name add_filter_branch
#' @rdname add_filter_branch
#' @family filter branch functions
#' @export
add_filter_branch <- function(.mverse, ...) {
  nms <- sapply(rlang::enquos(...), rlang::quo_name)
  brs <- list(...)
  stopifnot(all(sapply(brs, inherits, "filter_branch")))
  .mverse <- add_branch(.mverse, brs, nms)
  invisible(.mverse)
}

code_branch_filter_branch <- function(.mverse, br) {
  multiverse::inside(
    .mverse,
    .data_mverse <- dplyr::filter(.data_mverse, !!parse(br))
  )
  invisible()
}
methods::setOldClass("filter_branch")
methods::setMethod("code_branch",
                   signature = signature(br = "filter_branch"),
                   code_branch_filter_branch)