Add backport for grepv()

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: backports
 Type: Package
 Title: Reimplementations of Functions Introduced Since R-3.0.0
-Version: 1.5.0
+Version: 1.5.0.9000
 Authors@R: c(
     person("Michel", "Lang", NULL, "michellang@gmail.com",
       role = c("cre", "aut"), comment = c(ORCID = "0000-0001-9754-0393")),

NEWS.md

@@ -1,3 +1,7 @@
+# backports (development version)
+
+* Added backport for the `grepv()` function from base for R versions prior to 4.5.0
+
 # backports 1.5.0
 
 * Added backport for the null-coalesce operator `%||%` for R versions prior to 4.4.0.

R/grepv.R

@@ -0,0 +1,36 @@
+#' @title Backport of grepv for R < 4.5.0
+#' @rdname grepv
+#'
+#' @description
+#' See the original description in [grepv()].
+#'
+#' @keywords internal
+#' @rawNamespace if (getRversion() < "4.5.0") export(grepv)
+#' @examples
+#' # get function from namespace instead of possibly getting
+#' # implementation shipped with recent R versions:
+#' bp_hasName = getFromNamespace("grepv", "backports")
+#'
+#' grepv("[a-m]", letters)
+grepv = function(
+  pattern,
+  x,
+  ignore.case = FALSE,
+  perl = FALSE,
+  value = TRUE,
+  fixed = FALSE,
+  useBytes = FALSE,
+  invert = FALSE
+) {
+  grep(
+    pattern = pattern,
+    x = x,
+    ignore.case = ignore.case,
+    perl = perl,
+    value = value,
+    fixed = fixed,
+    useBytes = useBytes,
+    invert = invert
+  )
+}
+

README.md

@@ -60,6 +60,9 @@ Note that the braces `{}` are necessary in the
 `NAMESPACE` file, even though they wouldn't be for regular R code, and that you might get a warning
 for including `backports` in the `Imports:` section of your `DESCRIPTION` file if you never end up using it.
 
+## Backports for R versions prior to 4.5.0
+
+* `base::grepv()`
 
 ## Backports for R versions prior to 3.2.0
 

tests/test-grepv.R

@@ -0,0 +1,10 @@
+source("helper/helper.R")
+
+if (exists("grepv", envir = baseenv())) {
+  f = get("grepv", envir = baseenv())
+  expect_same = makeCompareFun(f, backports:::grepv)
+
+  expect_same("[a-m]", letters)
+  expect_same("^\\w{2}", colnames(mtcars))
+}
+