Move functions

R/dev_utilities.R

@@ -159,3 +159,79 @@ valid_time_units <- function() {
 contains_vars <- function(arg) {
   inherits(arg, "quosures") && all(map_lgl(arg, quo_is_symbol) | names(arg) != "")
 }
+
+#' Turn a List of Quosures into a Character Vector
+#'
+#' @param quosures A `list` of `quosures` created using [`vars()`]
+#'
+#' @return A character vector
+#'
+#' @author Thomas Neitmann
+#'
+#' @export
+#'
+#' @keywords remove_utility
+#'
+#' @examples
+#' vars2chr(vars(USUBJID, AVAL))
+vars2chr <- function(quosures) {
+  rlang::set_names(
+    map_chr(quosures, ~ as_string(quo_get_expr(.x))),
+    names(quosures)
+  )
+}
+
+#' Negate List of Variables
+#'
+#' The function adds a minus sign as prefix to each variable.
+#'
+#' This is useful if a list of variables should be removed from a dataset,
+#' e.g., `select(!!!negate_vars(by_vars))` removes all by variables.
+#'
+#' @param vars List of variables created by `vars()`
+#'
+#' @return A list of `quosures`
+#'
+#' @author Stefan Bundfuss
+#'
+#' @export
+#'
+#' @keywords remove_utility
+#'
+#' @examples
+#' negate_vars(vars(USUBJID, STUDYID))
+negate_vars <- function(vars = NULL) {
+  assert_vars(vars, optional = TRUE)
+  if (is.null(vars)) {
+    NULL
+  } else {
+    lapply(vars, function(var) expr(-!!quo_get_expr(var)))
+  }
+}
+
+#' Optional Filter
+#'
+#' Filters the input dataset if the provided expression is not `NULL`
+#'
+#' @param dataset Input dataset
+#' @param filter A filter condition. Must be a quosure.
+#'
+#' @return A `data.frame` containing all rows in `dataset` matching `filter` or
+#' just `dataset` if `filter` is `NULL`
+#'
+#' @author Thomas Neitmann
+#'
+#' @export
+#'
+#' @keywords remove_utility
+#'
+filter_if <- function(dataset, filter) {
+  assert_data_frame(dataset)
+  assert_filter_cond(filter, optional = TRUE)
+
+  if (quo_is_null(filter)) {
+    dataset
+  } else {
+    filter(dataset, !!filter)
+  }
+}