I’ve seen some great maps recently.
just how much category theory was needed to establish this fact?
Not so much after all!
Program Reduction: A Win for Recursion Schemes
I also must confess to a strong bias against the fashion for reusable code. To me, “re-editable code” is much, much better than an untouchable black box or toolkit. I could go on and on about this. If you’re totally convinced that reusable code is wonderful, I probably won’t be able to sway you anyway, but you’ll never convince me that reusable code isn’t mostly a menace.
IMO parser combinators are way overused.
I’m really looking forward to using something like this.
Supposedly the last word in Haskell pipes / streaming libraries.
Dorothy lived in the midst of the great Kansas prairies, with Uncle Henry, who was a farmer, and Aunt Em, who was the farmer’s wife. She met me, she went on to say, when I was working next door to their farm under the shadow of the rocket gantry for the First Mars Expedition.
I have no memory of this.
She would have been a little girl and, oh lord, there were so many little kids hanging around outside the Fence watching us work. The little girls all wanted to talk to the Lady Astronaut. To me.
Guillaume Boisseau, Jeremy Gibbons
Abstract Profunctor optics are a neat and composable representation of bidirectional data accessors, including lenses, and their dual, prisms. The profunctor representation exploits higher-order functions and higher-kinded type constructor classes, but the relationship between this and the familiar representation in terms of “getter” and “setter” functions is not at all obvious. We derive the profunctor representation from the concrete representation, making the relationship clear. It turns out to be a fairly direct application of the Yoneda Lemma, arguably the most important result in category theory. We hope this derivation aids understanding of the profunctor representation. Conversely, it might also serve to provide some insight into the Yoneda Lemma.
Emily Riehl.
Proves a x (b + c) = (a x b) + (a x c) via Yoneda.