It works!

String Like Perl Array in Swift

class StringLikePerlArray {
    var text :String = ""

    init(_ string :String = ""){
        text = string
    }

    func count()->Int {
        var count :Int = 0
        for string in text {
            count++
        }
        return count
    }
    
    func pop() -> String {
        if self.count() == 0 { return "" }
        let removed = self.text.removeAtIndex(self.text.endIndex.predecessor())
        return String(removed)
    }

    func push(value: String) -> String {
        self.text.insert(Character(value), atIndex: self.text.startIndex)
        return self.text
    }
    
    func shift() -> String {
        if self.count() == 0 { return "" }
        let removed = self.text.removeAtIndex(self.text.startIndex)
        return String(removed)
    }
    
    func unshift(value: String) -> String {
        self.text.insert(Character(value), atIndex: self.text.endIndex)
        return self.text
    }
}

let a = StringLikePerlArray("String")   // (text "String")
a.count()                               // 6
a.text = "another String"               // (text "anotherString")
a.count()                               // 14
a.push("1")                             // "1anotherString"
a.count()                               // 15
a.unshift("F")                          // "1anotherStringF"
a.shift()                               // "1"
a.shift()                               // "a"
a.pop()                                 // "F"
a.count()                               // 13
a.text                                  // "nother String"