Add cross argument to num_range()

NEWS.md

@@ -1,8 +1,12 @@
 # tidyselect (development version)
 
+* `num_range()` now recycles its arguments using tidyverse rules (#355).
+  In addition, it gains a `cross` argument that allows you to take the
+  cartesian product of these arguments instead.
+
 * `eval_select(allow_empty = FALSE)` gains a new argument to yield a better error
   message in case of empty selection (@olivroy, #327)
-  
+
 * `eval_select()` and `eval_relocate()` gain a new `error_arg` argument that can be specified to throw a better error message when `allow_empty = FALSE`.
 
 * `eval_select()` and `eval_relocate()` throw a classed error message when `allow_empty = FALSE` (@olivroy, #347).
@@ -45,17 +49,17 @@
 
   * `any_of()` generates a more informative error if you supply too many
     arguments (#241).
-  
-  * `all_of()` (like `any_of()`) returns an integer vector to make it easier 
-    to combine in functions (#270, #294). It also fails when it can't find 
+
+  * `all_of()` (like `any_of()`) returns an integer vector to make it easier
+    to combine in functions (#270, #294). It also fails when it can't find
     variables even when `strict = FALSE`.
-  
+
   * `matches()` recognises and correctly uses stringr pattern objects
     (`stringr::regex()`, `stringr::fixed()`, etc) (#238). It also now
     works with named vectors (#250).
-  
+
   * `num_range()` gains a `suffix` argument (#229).
-  
+
   * `where()` is now exported, like all other select helpers (#201),
     and gives more informative errors (#236).
 
@@ -65,27 +69,27 @@
 * `eval_select()` always returns a named vector, even when renaming is not
   permitted (#220).
 
-* `eval_select()` and `eval_relocate()` gain new `allow_empty` argument which 
+* `eval_select()` and `eval_relocate()` gain new `allow_empty` argument which
   makes it possible to forbid empty selections with `allow_empty = FALSE` (#252).
 
 * `eval_select(allow_rename = FALSE)` no longer fails with empty
-  selections (#221, @eutwt) or with predicate functions (#225). It now properly 
+  selections (#221, @eutwt) or with predicate functions (#225). It now properly
   fails with partial renaming (#305).
 
 * `peek_var()` error now generates hyperlink to docs with recent RStudio (#289).
 
 * `vars_pull()` generates more informative error messages (#234, #258, #318)
   and gains `error_call` and `error_arg` arguments.
 
-* Errors produced by tidyselect should now be more informative. Evaluation 
-  errors are now chained, with the child error call is set to the `error_call` 
-  argument of `eval_select()` and `eval_rename()`. We've also improved 
-  backtraces of base errors, and done better at propagating the root 
+* Errors produced by tidyselect should now be more informative. Evaluation
+  errors are now chained, with the child error call is set to the `error_call`
+  argument of `eval_select()` and `eval_rename()`. We've also improved
+  backtraces of base errors, and done better at propagating the root
   `error_call` to vctrs input checkers.
 
 * `tidyselect_verbosity` is no longer used; deprecation messaging is now
   controlled by `lifecycle_verbosity` like all other packages (#317).
-  
+
 # tidyselect 1.1.2
 
 * Fix for CRAN checks.

R/helpers-pattern.R

@@ -174,14 +174,29 @@
 #' @param range A sequence of integers, like `1:5`.
 #' @param width Optionally, the "width" of the numeric range. For example,
 #'   a range of 2 gives "01", a range of three "001", etc.
+#' @inheritParams rlang::args_dots_empty
+#' @param cross Whether to take the cartesian product of `prefix`, `range`, and `suffix`.
+#'   If `FALSE`, the default, these arguments are recycled using tidyverse rules.
 #' @export
 num_range <- function(prefix,
                       range,
                       suffix = "",
                       width = NULL,
+                      ...,
+                      cross = FALSE,
                       vars = NULL) {
+  check_dots_empty()
   vars <- vars %||% peek_vars(fn = "num_range")
 
+  if (cross) {
+    args <- vctrs::vec_expand_grid(prefix = prefix, range = range, suffix = suffix)
+  } else {
+    args <- vctrs::vec_recycle_common(prefix = prefix, range = range, suffix = suffix)
+  }
+  prefix <- args$prefix
+  range <- args$range
+  suffix <- args$suffix
+
   if (!is_null(width)) {
     range <- sprintf(paste0("%0", width, "d"), range)
   }

tests/testthat/_snaps/helpers-pattern.md

@@ -1,3 +1,23 @@
+# num_range recycles with tidyverse rules (#355)
+
+    Code
+      select_loc(vars, num_range(c("x", "y"), 1:3))
+    Condition
+      Error in `select_loc()`:
+      i In argument: `num_range(c("x", "y"), 1:3)`.
+      Caused by error in `num_range()`:
+      ! Can't recycle `prefix` (size 2) to match `range` (size 3).
+
+---
+
+    Code
+      select_loc(vars, num_range(c("x", "y"), 1:2, c("_foo", "_bar", "_baz")))
+    Condition
+      Error in `select_loc()`:
+      i In argument: `num_range(c("x", "y"), 1:2, c("_foo", "_bar", "_baz"))`.
+      Caused by error in `num_range()`:
+      ! Can't recycle `prefix` (size 2) to match `suffix` (size 3).
+
 # matches() complains about bad stringr pattern usage
 
     Code

tests/testthat/test-helpers-pattern.R

@@ -68,6 +68,49 @@ test_that("num_range can use a suffix (#229)", {
   expect_named(select_loc(vars, num_range("x", 1:2, "_y")), c("x1_y", "x2_y"))
 })
 
+test_that("num_range recycles with tidyverse rules (#355)", {
+  vars <- set_names(c("x1", "y1", "y2", "x2", "x3"))
+  expect_snapshot(
+    error = TRUE,
+    select_loc(vars, num_range(c("x", "y"), 1:3)),
+  )
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:2)),
+    c("x1", "y2")
+  )
+
+  vars <- set_names(c("x1_foo", "y1_bar", "y1_foo", "x2_bar", "x3_bar", "y2_bar"))
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:2, "_foo")),
+    "x1_foo"
+  )
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:2, c("_foo", "_bar"))),
+    c("x1_foo", "y2_bar")
+  )
+  expect_snapshot(
+    error = TRUE,
+    select_loc(vars, num_range(c("x", "y"), 1:2, c("_foo", "_bar", "_baz"))),
+  )
+})
+
+test_that("num_range crosses ranges with prefixes and suffixes if requested (#355)", {
+  vars <- set_names(c("x1", "y1", "y2", "x2", "x3"))
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:3, cross = TRUE)),
+    c("x1", "x2", "x3", "y1", "y2")
+  )
+
+  vars <- set_names(c("x1_foo", "y1_bar", "y1_foo", "x2_bar", "x3_bar", "y2_bar"))
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:3, "_foo", cross = TRUE)),
+    c("x1_foo", "y1_foo")
+  )
+  expect_named(
+    select_loc(vars, num_range(c("x", "y"), 1:3, c("_foo", "_bar"), cross = TRUE)),
+    c("x1_foo", "x2_bar", "x3_bar", "y1_foo", "y1_bar", "y2_bar")
+  )
+})
 
 test_that("matchers accept length > 1 vectors (#50)", {
   expect_identical(

tests/testthat/test-helpers.R

@@ -1,4 +1,3 @@
-
 test_that("one_of gives useful errors", {
   expect_snapshot(error = TRUE, cnd_class = TRUE, {
     one_of(1L, .vars = c("x", "y"))