[swift-evolution] Customized Inline Init Closure

[Jo Albright]

Here is another option. Attached is a playground I was messing around with. There are some weird bugs I was noticing, but don’t quite know if they are important enough to submit (comment out line 54 to see).

I actually like using the $0 so as to allow access to self if using within another type (ex: view controller code below).

Please respond with any potential issues with the code I have written.

- Jo



protocol ClosureInit { init() }

extension ClosureInit {

    init(@noescape b: inout Self -> Void) { self.init(); b(&self) }
    
}

struct Person: ClosureInit {
    
    enum GenderType: String { case Male, Female }
    
    var age: Int = 0
    var gender: GenderType?
    var name: String?
    
}

let me = Person {
    
    $0.name = "Jo"
    $0.age = 32
    $0.gender = .Male
    
}

me.age // 32

extension Array: ClosureInit { }

let randomIntArray = [Int] {
    
    for _ in 0...10 {
        
        $0.append(Int(arc4random_uniform(100)))
        
    }
    
}

randomIntArray

let personArray = [Person] {

    for _ in 0...8 {
        
        $0.append(Person {
            
            $0.age = Int(arc4random_uniform(100))
            $0.gender = Int(arc4random_uniform(100)) % 2 == 0 ? .Male : .Female // comment this line out to see error
            
            
        })
        
    }

}

personArray

extension UIView: ClosureInit { }

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        UILabel {
            
            $0.text = "This is Awesome!"
            $0.textColor = UIColor.cyanColor()
            $0.frame = CGRect(x: 20, y: 20, width: view.frame.width - 40, height: 40)
            view.addSubview($0)
            
        }
        
        view.addSubview(UIButton {
            
            $0.setTitle("Submit", forState: .Normal)
            $0.frame = CGRect(x: 20, y: 60, width: view.frame.width - 40, height: 40)
            
        })
        
        
    }
    
}

let vc = ViewController()

vc.loadViewIfNeeded()

vc.view.subviews




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160104/5204d231/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ClosureInit.playground.zip
Type: application/zip
Size: 11767 bytes
Desc: not available
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160104/5204d231/attachment.zip>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160104/5204d231/attachment-0001.html>