Add suffix argument to num_range() (#286)

Fixes #229

NEWS.md

@@ -1,5 +1,7 @@
 # tidyselect (development version)
 
+* `num_range()` gains a `suffix` argument (#229).
+
 * `eval_select()` always returns a named vector, even when renaming is not
   permitted (#220).
 

R/helpers-pattern.R

@@ -168,13 +168,14 @@ matches <- function(match,
 }
 
 #' @rdname starts_with
-#' @param prefix A prefix that starts the numeric range.
+#' @param prefix,suffix A prefix/suffix added before/after the numeric range.
 #' @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.
 #' @export
 num_range <- function(prefix,
                       range,
+                      suffix = "",
                       width = NULL,
                       vars = NULL) {
   vars <- vars %||% peek_vars(fn = "num_range")
@@ -183,7 +184,7 @@ num_range <- function(prefix,
     range <- sprintf(paste0("%0", width, "d"), range)
   }
 
-  match_vars(paste0(prefix, range), vars)
+  match_vars(paste0(prefix, range, suffix), vars)
 }
 
 check_match <- function(match) {

tests/testthat/test-helpers-pattern.R

@@ -63,6 +63,11 @@ test_that("num_range selects numeric ranges", {
   expect_equal(select_loc(vars, num_range("x", 10:11, width = 2)), c(x10 = 5L, x11 = 6L))
 })
 
+test_that("num_range can use a suffix (#229)", {
+  vars <- set_names(c("x1", "x2", "x1_y", "x2_y"))
+  expect_named(select_loc(vars, num_range("x", 1:2, "_y")), c("x1_y", "x2_y"))
+})
+
 
 test_that("matchers accept length > 1 vectors (#50)", {
   expect_identical(