swift-trailing-closures.swift

//
//  main.swift
//  SwiftTests
//
//  Created by Thiago Andrade on 2017-01-08.
//  Copyright © 2017 Thiago Andrade. All rights reserved.
//

import Foundation

func sum(_ a: Int, _ b: Int, clos: ((Int) -> ())? = nil) {

  if let clos = clos {
    clos(a + b);
  } else {
    print("do nothing with ", (a + b));
  }
}

func times(_ a: Int, _ b: Int, clos: ((Int) -> ())) {
  clos(a * b);
}

print("Closure sum");

sum(1, 2);
sum(1, 2) { v in };
sum(8, 7) { v in
  print("printing value with closure callback:", v);
}

times(3, 4) { v in
  print("printing value with closure callback:", v);
};

sum(8, 7) { v in
  times(v, 2) { v in
    print("inner inner closure printing value with closure callback:", v);
  };
}