A functional wrapper around NSMutableAttributedString

JFTextStyle.swift

/*
  let myName = NSMutableAttributedString(string: " Hey, what's up!? ")
  let yellowOnBlack = Styles.textBackground(.redColor(), range: NSMakeRange(2, 3)) >>> Styles.textColor(.darkGrayColor())
  let label = UILabel(frame: CGRectMake(10, 50, 200, 50))
  label.attributedText = yellowOnBlack(myName)
  view.addSubview(label)
*/

import UIKit
import Foundation

typealias TextStyle = NSMutableAttributedString -> NSMutableAttributedString

infix operator >>> { associativity left }

func >>> (style1: TextStyle, style2: TextStyle) -> TextStyle {
    return { string in
        style2(style1(string))
    }
}

class Styles {
    static func textBackground(color: UIColor, range: NSRange? = nil) -> TextStyle {
        return { mutableAttributedString in
            let newString = NSMutableAttributedString(attributedString: mutableAttributedString)
            if let r = range {
                newString.addAttribute(NSBackgroundColorAttributeName, value: color, range: r)
            } else {
                let r = NSRange(location: 0, length: mutableAttributedString.string.characters.count)
                newString.addAttribute(NSBackgroundColorAttributeName, value: color, range: r)
            }
            return newString
        }
    }

    static func textColor(color: UIColor) -> TextStyle {
        return { mutableAttributedString in
            let newString = NSMutableAttributedString(attributedString: mutableAttributedString)
            let range = NSRange(location: 0, length: mutableAttributedString.string.characters.count)
            newString.addAttribute(NSForegroundColorAttributeName, value: color, range: range)
            return newString
        }
    }
}