Circular Reference async

circularasync.swift

class Person{
    
    var name: String
    
    init(name: String) {
        print("--- init \(name) ---")
        self.name = name
    }
    
    deinit {
        print("--- deinit \(name) ---")
    }
    
    func normalHello(){
        print("Hello, I am \(name)!")
    }
    
    // MARK: - Closure関連
    private var keepingClosure:(()->Void)?

    // これはescaping
    private func keepAndDo(_ closure:@escaping (()-> Void)){
        self.keepingClosure = closure
        closure()
    }
    
    // これはnoescape（デフォルトは noescape）
    private func justDo(_ closure: (()-> Void)){
        closure()
    }
    
    // MARK: - Hello系
    func strongHello(){
        self.keepAndDo {
            DispatchQueue.main.asyncAfter(
                deadline: DispatchTime.now() + 1.0,
                execute: {
                
                    print("....\(self.name) [strong]")
            })

            self.normalHello()
        }
    }
    
    func weakHello(){
        self.keepAndDo { [weak self] in
            self?.normalHello()
            
            DispatchQueue.main.asyncAfter(
                deadline: DispatchTime.now() + 1.0,
                execute: {
                    
                    print("....\(self?.name) [weak]")
            })
            
        }
    }
    
    func noescapeHello(){
        self.justDo {
            
            self.normalHello()
            
            DispatchQueue.main.asyncAfter(
                deadline: DispatchTime.now() + 1.0,
                execute: {
                    
                    print("....\(self.name) [noescape]")
            })

        }
    }
    
    func noescapeAndWeakHello(){
        self.justDo {
            
            self.normalHello()
            
            DispatchQueue.main.asyncAfter(
                deadline: DispatchTime.now() + 1.0,
                execute: {[weak self] in
                    
                    print("....\(self?.name) [noescape and weak]")
            })
            
        }
    }
    
}