Add locale and ignore_case arguments to str_unique()

For consistency with str_equal()

Author: hadley

R/unique.R

@@ -4,17 +4,27 @@
 #' how duplication is measured.
 #'
 #' @inheritParams str_detect
-#' @param ... Other options used to control matching behavior between duplicate
-#'   strings. Passed on to [stringi::stri_opts_collator()].
+#' @inheritParams str_equal
 #' @return A character vector, usually shorter than `string`.
 #' @seealso [unique()], [stringi::stri_unique()] which this function wraps.
 #' @examples
 #' str_unique(c("a", "b", "c", "b", "a"))
 #'
+#' str_unique(c("a", "b", "c", "B", "A"))
+#' str_unique(c("a", "b", "c", "B", "A"), ignore_case = TRUE)
+#'
 #' # Use ... to pass additional arguments to stri_unique()
 #' str_unique(c("motley", "mötley", "pinguino", "pingüino"))
 #' str_unique(c("motley", "mötley", "pinguino", "pingüino"), strength = 1)
 #' @export
-str_unique <- function(string, ...) {
-  stri_unique(string, opts_collator = stri_opts_collator(...))
+str_unique <- function(string, locale = "en", ignore_case = FALSE, ...) {
+  check_string(locale)
+  check_bool(ignore_case)
+
+  opts <- str_opts_collator(
+    locale = locale,
+    ignore_case = ignore_case,
+    ...
+  )
+  stri_unique(string, opts_collator = opts)
 }

man/str_unique.Rd

@@ -2,3 +2,7 @@ test_that("unique values returned for strings with duplicate values", {
   expect_equal(str_unique(c("a", "a", "a")), "a")
   expect_equal(str_unique(c(NA, NA)), NA_character_)
 })
+
+test_that("can ignore case", {
+  expect_equal(str_unique(c("a", "A"), ignore_case = TRUE), "a")
+})