Lenses are becoming an increasingly important part of a Haskeller’s toolkit. Yet, when first approaching them, people may feel buried under a myriad of different lens-like thingies, and the complexity of some of the libraries implementing those concepts, like lens.
The goal of this fast-paced mini-course is to provide a conceptual overview of the most important kinds of optics, including lenses, prisms, and traversals.
For most data types, those optics can be automatically generated, something we shall discuss.
Finally, we shall look at one useful application of optics: treating semi-structured data such as JSON documents.
Using and Composing Lenses
Creating Lenses
Affine-Traversals
Prisms
First-class Everything
Traversals and Folds
JSON Manipulation using Optics
Optics and State
The Rest of the Optics Hierarchy
All Courses, Haskell
Before your Haskell journey started, you might have heard of “functors” and “monads.” What are they? Do Haskellers really use them as often as it seems?
