acronym.swift

extension String {
    var acronym:String {
        let chSet = NSMutableCharacterSet.punctuationCharacterSet()
        chSet.addCharactersInString("\n\r ")
        let words = self.componentsSeparatedByCharactersInSet(chSet)
        let letters = words.flatMap { $0.characters.first }.map { String($0) }
        return letters.joinWithSeparator("").uppercaseString
    }
}