Swift Trimming Trailing Punctuation

Lately, I’ve been working on a project that requires some basic MLP text processing to be performed on device.  A component of our text processing involved removing any trailing punctuation, no matter the language.

I’ve found the below String Extension is a good balance between effectiveness, performance, and readability.  Especially if you are collecting input from users prone to excessive punctuation.

extension String {
func trimTrailingPunctuation() -> String {
return self.trimmingCharacters(in: .whitespacesAndNewlines)
.trimmingCharacters(in: .punctuationCharacters)
.trimmingCharacters(in: .whitespacesAndNewlines)
let example1 = "How are you???".trimTrailingPunctuation()
>>> How are you
let example2 = "Hi!!!!".trimTrailingPunctuation()
>>> Hi
let example3 = "Act limited time offer now!".trimTrailingPunctuation()
>>> Act limited time offer now