Introduction to Promises in Swift

Thomas KarpiniecPart of DW17

A promise is a popular programming pattern for performing tasks in the background. A powerful syntax using closures lets you start a task and define success and failure handlers all in one place. Promises are used in many languages but Swift’s convenient closure syntax makes them especially pleasant. This talk explains when promises are useful and demonstrates how to use them in typical programming scenarios, including chaining promises together and aggregating results. Demos use Swift 3 and a popular third party library called PromiseKit.


Tom is a developer and Linux tinkerer from Hobart who spends much of his time in Xcode. He has a long interest in computing privacy issues and enjoys experimenting with decentralised software. He is an amateur radio operator and often tries to communicate with his neighbours at 1200 baud or less.