Haskell

Basic optics: lenses, prisms, and traversals in Haskell

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 talk is to provide a conceptual overview of three of the most important kinds of optics, namely 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.

Joachim Breitner and David Christiansen interview John MacFarlane, a professor of philosophy at UC Berkeley, but also the author of the popular pandoc document conversion tool, which has been around half as long as Haskell itself. He also explains the principle of uniformity as a design goal for lightweight markup languages, the relationship between philosophy and programming, and along the way he helps David with his markdown difficulties.

This is a spot where you can ask anything that you feel doesn't deserve its own post, no matter how small or simple it is!

On /r/Haskell there was a pinned, monthly thread so that people could ask questions without creating a new top-level post.

• I'd like to increase traffic to here (or some other Haskell Fediverse threaded-conversation group). Do you think a thread like that might help?
• Does pinning work here? It's probably not necessary given the posts/month currently, but I suppose it's something to keep in mind.
• Anyone got a link to Lemmy/KBin/ActivityPub Haskell library that I could use to write a bot, or some other way to schedule a post for yyyy-mm-01T00:00:00Z ?

cross-posted from: https://programming.dev/post/5838448

I came across this semi-randomly by using Search Marginalia to find information on functional programming courses.

I also very much enjoyed the two articles referenced in the footnotes.