Promises
Promises is a modern framework that provides synchronization
Promises is a modern framework that provides a synchronization construct for Objective-C and Swift to facilitate writing asynchronous code. Typically, async operations take a completion handler in a form of a block, which is called to provide either a result or an error. To perform more than one async operation, you have to nest the second one inside the completion block of the first one, and also handle an error gracefully. Often such nesting becomes painful to follow or modify. The framework...