Merge pull request #16 from poissonconsulting/str_replace_when

Str replace when function

NAMESPACE

@@ -12,6 +12,7 @@ export(only)
 export(replace_na_if)
 export(str_crush)
 export(str_detect2)
+export(str_replace_vec)
 export(str_to_snake_case)
 export(summarise2)
 export(summarize2)

R/str-replace_vec.R

@@ -0,0 +1,34 @@
+#' String replace multiple strings
+#' 
+#' String replace multiple strings in a vector. 
+#'
+#' `str_replace_vec()` is a vectorized form of [`stringr::str_replace()`].
+#' 
+#' This is different from passing a named vector to [`stringr::str_replace_all`], 
+#' which performs multiple replacements but to all pattern matches in a string.
+#' 
+#' @param replace A character vector where the names are the patterns to look
+#' for and the values are the replacement values (c(pattern1 = replacement1))
+#' @inherit stringr::str_replace
+#' @seealso [`stringr::str_replace()`] and [`stringr::str_replace_all()`]
+#' @export
+#' @examples 
+#' fruits <- c("two apples", "nine pears")
+#' str_replace_vec(fruits, c("two" = "three", "nine" = "ten"))
+
+str_replace_vec <- function(string, replace) {
+  chk_character(string)
+  chk_character(replace)
+  chk_named(replace)
+
+  if(!length(replace)) return(string)
+
+  pattern <- names(replace)
+
+  n <- length(replace)
+
+  for(i in seq_len(n)) {
+    string <- stringr::str_replace(string, pattern = pattern[i], replacement = replace[i])
+  }
+  string
+}

tests/testthat/test-str-replace-vec.R

@@ -0,0 +1,61 @@
+test_that("str_replace_vec works with mutate", {
+  data <- tibble::tibble(
+    x = c("one", "two", "three", "four"),
+    y = c("one apple", "two bananas", "three pear", "four oranges"))
+
+  data <- dplyr::mutate(data,
+                        x2 = str_replace_vec(x, c("one" = "1",
+                                                  "two" = "2",
+                                                  "three" = "3",
+                                                  "four" = "4")))
+
+  expect_identical(data$x2, c("1", "2", "3", "4"))
+  expect_identical(data$y, c("one apple", "two bananas", "three pear", "four oranges"))
+})
+
+test_that("str_replace_vec with regex", {
+  x <- c("REP_1", "REP1-2", "MR REP 2")
+
+  x2 <- str_replace_vec(x, c("(?<!(\\d|\\s))[:punct:]" = "-", # punctuation not preceded by a digit or space
+                             "(?<=REP)\\s" = "-", # a space precded by REP
+                             "REP(?=\\d)" = "REP-", # REP followed by a digit
+                             "^[:alpha:]+\\s(?=REP)" = "")) # Letters with space at start of string followed by REP
+
+  expect_identical(x2, c("REP-1", "REP-1-2", "REP-2"))
+})
+
+test_that("str_replace_vec with non character strings", {
+  x <- c("one", "two", "three", "four", "five")
+
+  x2 <- str_replace_vec(x, c("one" = NULL,
+                             "two.*" = NA_character_,
+                             "three" = TRUE,
+                             "four" = character(0),
+                             "five" = 5L))
+
+  expect_identical(x2, c("one", NA_character_, "TRUE", "four", 5L))
+  expect_type(x2, "character")
+})
+
+test_that("str_replace_vec with x no length", {
+  x <- c(character(0))
+  expect_length(x, 0)
+  x2 <- str_replace_vec(x, c("one" = "1"))
+
+  expect_identical(x2, character(0))
+
+  x <- c()
+  expect_length(x, 0)
+  replace <- c("one" = "1")
+
+  expect_error(str_replace_vec(x, replace))
+})
+
+test_that("str_replace_vec with replace no length", {
+  x <- c("one", "two", "three", "four")
+  replace <- c()
+  expect_error(str_replace_vec(x, replace))
+
+  replace <- c(character(0))
+  expect_error(str_replace_vec(x, replace))
+})