Chainable

Sintactic sugar for chainable actions over objects

It provides some methods to make creating and working with objects in a functional way.

Any.then

func then(_ block: (inout Self) throws -> Void) rethrows -> Self

For Value types. Allows chained modifications.

struct Obj {
    var a: String
    var b: Int
}

let o = Obj(a: "hola", b: 0)

let c = o.then {
    $0.a = "adios"
}

AnyObject.then

func then(_ block: (Self) throws -> Void) rethrows -> Self

Same as previous but for Reference types. Very useful for in-place initialization.

class VC: UIViewController {

    lazy var button = UIButton().then {
        $0.addTarget(self, action: #selector(action), for: .touchUpInside)
    }
    
    @IBAction
    func action() {
        …
    }
}

Any.do

func do(_ block: (Self) throws -> Void) rethrows

Allows terminations actions with objects

Obj(a: "hola", b: 0).then { $0.b = 3 }.do(print)