Functional Error Handling with Cats

Sometimes we want to keep or collect errors for later examination. We’ll use Cats to help us pick the story we want to tell when handling errors; accumulated errors or first error wins. Monads will be included!

Learn about the ApplictiveError[_], MonadError[_], Validated[_, _], and Chain[_] type classes. And how to use them for handling errors in a functional way, via accumulation or monadically.

Assumes prior knowledge of Cats, common type classes, and common ADTs.

Presented as a slide show.