ianmcook commented on a change in pull request #9745:
URL: https://github.com/apache/arrow/pull/9745#discussion_r601843411



##########
File path: r/R/dplyr.R
##########
@@ -689,17 +741,77 @@ abandon_ship <- function(call, .data, msg = NULL) {
   eval.parent(call, 2)
 }
 
-arrange.arrow_dplyr_query <- function(.data, ...) {
+arrange.arrow_dplyr_query <- function(.data, ..., .by_group = FALSE) {
+  call <- match.call()
+  exprs <- quos(...)
+  if (.by_group) {
+    # when the data is is grouped and .by_group is TRUE, order the result by
+    # the grouping columns first
+    exprs <- c(quos(!!!dplyr::groups(.data)), exprs)
+  }
+  if (length(exprs) == 0) {
+    # Nothing to do
+    return(.data)
+  }
   .data <- arrow_dplyr_query(.data)
-  if (query_on_dataset(.data)) {
-    not_implemented_for_dataset("arrange()")
+  # find and remove any dplyr::desc() and tidy-eval
+  # the arrange expressions inside an Arrow data_mask
+  sorts <- vector("list", length(exprs))
+  descs <- logical(0)
+  mask <- arrow_mask(.data)
+  for (i in seq_along(exprs)) {
+    x <- find_and_remove_desc(exprs[[i]])
+    exprs[[i]] <- x[["quos"]]
+    sorts[[i]] <- arrow_eval(exprs[[i]], mask)
+    if (inherits(sorts[[i]], "try-error")) {
+      msg <- paste('Expression', as_label(exprs[[i]]), 'not supported in 
Arrow')
+      return(abandon_ship(call, .data, msg))
+    }
+    names(sorts)[i] <- as_label(exprs[[i]])
+    descs[i] <- x[["desc"]]
   }
-  # TODO(ARROW-11703) move this to Arrow
-  call <- match.call()
-  abandon_ship(call, .data)
+  .data$arrange_vars <- c(sorts, .data$arrange_vars)
+  .data$arrange_desc <- c(descs, .data$arrange_desc)
+  .data
 }
 arrange.Dataset <- arrange.ArrowTabular <- arrange.arrow_dplyr_query
 
+# Helper to handle desc() in arrange()
+# * Takes a quosure as input
+# * Returns a list with two elements:
+#   1. The quosure with any wrapping parentheses and desc() removed
+#   2. A logical value indicating whether desc() was found
+# * Performs some other validation
+find_and_remove_desc <- function(quosure) {
+  expr <- quo_get_expr(quosure)
+  descending <- FALSE
+  if (length(all.vars(expr)) < 1L) {
+    stop(
+      "Expression in arrange() does not contain any field names: ",
+      deparse(expr),
+      call. = FALSE
+    )
+  }
+  while (identical(typeof(expr), "language") && is.call(expr)) {

Review comment:
       Comment explaining the while loop added in 
da1b7464ae0092e95f77829e0dabc48529074b93




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