Functional Formatting in Swift: NSAttributedString

ViewController.swift

import UIKit

class ViewController: UIViewController {
    typealias CharacterStyle = String -> NSAttributedString
    typealias ParagraphStyle = [NSAttributedString] -> NSAttributedString
    
    func paragraph(indent indent:CGFloat, spacing:CGFloat) -> ParagraphStyle {
        return { attrStrings in
            let para = NSMutableAttributedString()
            for s in attrStrings {
                para.appendAttributedString(s)
            }
            let paraStyle = NSMutableParagraphStyle()
            paraStyle.firstLineHeadIndent = indent
            paraStyle.paragraphSpacingBefore = spacing
            para.addAttribute(NSParagraphStyleAttributeName, value: paraStyle, range: NSRange(location: 0,length: para.string.characters.count))
            return para
        }
    }
    
    
    
    func bodyText(size:CGFloat, style:UIFontDescriptorSymbolicTraits?) -> CharacterStyle {
        var desc = UIFontDescriptor(fontAttributes: [UIFontDescriptorTextStyleAttribute:UIFontTextStyleBody])
        if let style = style {
            desc = desc.fontDescriptorWithSymbolicTraits(style)
        }
        let font = UIFont(descriptor: desc, size: size)
        return {
            string in
            return NSMutableAttributedString(string: string, attributes:[NSFontAttributeName:font])
        }
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.\
        
        // set font size and style traits
        let bodyStyle = bodyText(12, style: nil)
        let bodyStyleItalic = bodyText(12, style: .TraitItalic)
        
        // build an array of styled attributed strings
        let attrStrings = [bodyStyle("Hello Swift! This is a tutorial looking at "),
            bodyStyleItalic("attributed"), bodyStyle(" strings!")]
        // create a paragraph from the strings
        let para = paragraph(indent:10.0, spacing: 12.0)(attrStrings)

        
        // Create UITextView
        let view = UITextView(frame: CGRect(x: 0, y: 20, width: CGRectGetWidth(self.view.frame), height: CGRectGetWidth(self.view.frame)-20))
        
        // Add string to UITextView
        view.attributedText = para
        
        // Add UITextView to main view
        self.view.addSubview(view)
    }

    

}