Extending NSAttributedString to have a "join" method like String.

Extensions.swift

//
//  Extensions.swift
//
//  Created by Thomas Groshong on 10/8/14.
//  Copyright (c) 2014 IS 543. All rights reserved.
//

import Foundation

// Simple usage to join with spaces:
//   let arrayOfAttributedStrings = [NSAttributedString(string: "Bob"), NSAttributedString(string: "John")]
//   NSAttributedString(string: " ").join(arrayOfAttributedStrings)
//
extension NSAttributedString {
    func join(sequence: [NSAttributedString]) -> NSAttributedString {
        var mutableString = NSMutableAttributedString(attributedString: sequence[0])
        for index in 1 ..< sequence.count {
            mutableString.appendAttributedString(self)
            mutableString.appendAttributedString(sequence[index])
        }
        return NSAttributedString(attributedString: mutableString)
    }
}