Closures

Replaces verbose target-action and delegation with simple closures, as shown with `button.onTap { }` and `mySwitch.onChange { }`, drastically reducing boilerplate code for common UI interactions.

Allows mixing closure handlers with traditional delegate methods without lock-in, enabling gradual adoption—demonstrated in the 'Retain Control' section where UITableView can use custom delegates alongside closures.

Simplifies data source implementation for table and collection views by populating directly from arrays with methods like `tableView.addElements()`, minimizing repetitive cell configuration code.

Built using Swift's strong-typed system without Objective-C runtime tricks, ensuring better compile-time safety and seamless integration with modern Swift features, as emphasized in the philosophy section.