BFPG Meetup - May 2026 - zippers + the Datastar framework
Join the BFPG Discord: https://discord.gg/yYz2d8w7FY
Agenda
18:00: Welcome and setup
Presentation #1: What is the derivative of a data type? - Tim Lamberton
Presentation #2:
Datastar: the hypermedia framework - Carlo Hamalainen20:00ish: Pack down, head to Criterion pub
What is the derivative of a data type?
The same rules of differential calculus that you learned in high school can be applied to take derivatives of data types. These data type derivatives are very useful for exploring and efficiently modifying the original data. Welcome to the world of zippers, one-hole contexts and the surprising application of math for everyday programming.
A zipper is like a file explorer for your data structure, allowing you to enter nested structures, access and modify values efficiently, and find your way back out again. In this presentation we will discover a principled way to build zippers by data type differentiation.
The intended audience for this presentation is working programmers, students, and anyone interested in what sits at the intersection of mathematics and computers.
Datastar - the hypermedia framework
A quick tour of Datastar and my new (official!) Haskell SDK. Learn how to use Datastar's declarative framework to build interactive web apps from the backend.