michaelwix / futures

Async Programming Workshop

Exercises on Scala Futures

Introduction

Futures provide a simple way to run an asynchronous computation. Future starts a computation when you create it and then eventually returns the result. For example, every RPC invocation at Wix is a function that returns a Future of the RPC service result. See more information about Futures API in the documentation

Futures are composable. We consider the following common cases of Futures composition:

• Sequential composition with or without error accumulation;
• Concurrent composition with or without error accumulation;

See the details below.

Exercises

Kata1 "Fallback"

This is an exercise on the sequential Futures composition without error accumulation. This exercise uses composition of both sync and async operations.

Kata2 "Retry"

This is an exercise on the sequential Futures composition with error accumulation. This exercise uses a recursion although a non-recursive solution would be better.

Kata3 "Traverse"

This is an exercise on the concurrent Futures composition without error accumulation. This is just a straightforward use of Future.traverse.

Kata4 and Kata5 "Traverse with errors accumulation"

These are exercises on the concurrent Futures composition with error accumulation.