HackerTube.dev

Category Theory, The essence of interface-based design - Erik Meijer

FooCafe · 74.5K views · 2015-09-10 · 1:03:14

Open on YouTube ↗

If playback is restricted in your region, try opening the original video. Use Mark watched to add it to your marked videos.

Overview

Erik Meijer argues that category theory is the mathematicians' version of interface-based design. He shows that Java 8 lambdas and method references form a Cartesian closed category.

On Hacker News

It is cited as an authoritative take on category theory for programmers and API design.

Recommended by 1 HN people across 1 months · HN mentions 2016–2022

Topics

Search by tags

What people said

yenwel · 2018-10 · Recommendation

Also nice: Erik Meijer Explains it well: [VIDEO] (check out FP101 on edx) Statebox guys doing stuff with category theory, blockchain and petrinets: [LINK] [LINK] Graphical linear algebra: [LINK] Jules Hedges working on game theory : [LINK]

Read the original HN comment ↗
deltasevennine · 2022-11 · Reference

> I prefer the academic truth, validated by renowned peers in the industry, presented at acknowledged conferences, to random opinions on the Internet. You don't even know who wrote the IEEE definition and who validated it. Second this isn't academic truth. This is just some arbitrary chosen standard chosen by industry. Not academic at all. In mathematics, the ultimate logical form of academia there is a term for "interfaces". It's called categories, and there's a entire theoretical framework behind it called "Category Theory". This theory of "interfaces" goes beyond just OOP and category theory can be used to foundation-ally describe all of mathematics and function as a sort of replacement of set theory. Don't worship authority for authorities sake. If the IEEE declared 1+1=3 would you believe it? Instead use your own brain. Do my arguments have merit? Does the IEEE definition seem inconsistent? Does my definition make logical sense? If you can think of these things on your own merits instead of blindly following the IEEE then you'll see that the definition of OOP is just something academia hasn't really thought about deeply from a theoretical and mathematical standpoint. OOP is more like a term that comes from applied engineering with very little theoretical foundation. If you want some sort of authority I googled some authoritative talk about category theory explained to programmers: [VIDEO] I'm sure maybe you heard of haskell and category theory? Haskell is a purely functi

Read the original HN comment ↗
adamnemecek · 2017-01 · Reference

Erik Meijer gave a talk called "Category Theory, The essence of interface-based design" [VIDEO] Fundamentally, category theory is seen as some sort of holy grail of programming. The hope is that learning about only one API will let you interact naturally and composably with any interface conforming to that design.

Read the original HN comment ↗

Sources

Video by FooCafe, played through YouTube.

Data and selection notes

HN summaries and labels may contain AI errors. HN dates refer to discussions, not video publication.

HN Library: HackerTube export (2026-10-31) and open-index/hacker-news. Upstream summaries and classifications may contain AI errors.

Views, duration and playback status refresh separately from the published catalog. When an update fails, existing data remains visible.

Selection checks
  • SaaS & AI candidates: Topic keywords do not match
  • Editor-approved picks: Editorial review is required

Rule matches identify candidates. They do not guarantee video quality or financial results.

About the library and its sources