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"Controlling Time and Space: understanding the many formulations of FRP" by Evan Czaplicki

Strange Loop Conference

88K subscribers • 110 videos on Hallway • Conference channel

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  • Recommended by 8 people: 5 on Hacker News, 1 on Lobsters, 1 in engineering communities and 1 curated list.
  • A classic. People kept recommending it from 2014 to 2026.
  • Presented by Evan Czaplicki, creator of Elm
  • May be out of date. Uploaded 12 years ago, in an area where tools change fast.

Intermediate. Assumes working knowledge.

69K views12 years ago8 recommendations

Programming languagesWeb developmentFunctional programmingVue, Svelte, Angular and othersDebugging

Evan Czaplicki surveys the history and formulations of functional reactive programming and shows how Elm implements hot-swapping and debugging.

Functional Reactive Programming (FRP) is becoming an increasingly common way to structure event- driven code, but the term "FRP" actually refers to a large body of increasingly diverse work. This talk will quickly cover the basics of FRP, and then go into a couple different formulations of FRP that people are beginning to use. We will explore how these formulations fit together historically and theoretically. Finally, we will see how the particular variation of FRP used in Elm makes it easy to implement hot- swapping and Elm's Time Traveling Debugger. by Evan Czaplicki (@czaplic) - Prezi I am a functional programmer at heart, and my broad goal is to provide the tools and learning resources to make functional languages common in industry. I develop Elm 's compiler, tools, and community to make it great for projects within Prezi and in industry in general.

Why it's here

8 people recommend this

What people say. Recommended as an excellent overview of functional reactive programming concepts and their practical application in Elm.

Moments people linked to

u/alexander_bin r/haskell • Recommends

Elm "Controlling Time and Space: understanding the many formulations of FRP" by Evan Czaplicki

dcreon Hacker News • Recommends

On “Elm 0.14 – Simpler Core, Better Tools”

If you're interested in Elm but don't really know what it's about, I highly recommend Evan's Strange Loop talk, "Controlling Time and Space: understanding the many formulations of FRP." It will help to already have a bit of background in functional programming. link to this video

modulovalueon Hacker News • Recommends

On “We've had front end reactivity since 2018 – via Async Iterables”

…om framework derived from my observations back then). If we zoom out a bit, the problem is actually that we are trying to define a computation graph and then need a strategy for evaluation it. I think Elm has actually made the biggest progress on that front (here's THE talk on that topic that shows how complicated working out all the kinks can be: link to this video ) I still think that functional reactive programming solves most of the problems we have in UI-land, but th…

programming-talkscurated list on GitHubRecommends

Under “Elm”

Controlling Time and Space: understanding the many formulations of FRP 00:40:55 by **Evan Czaplicki** (2014)

platzon Hacker News • Recommends

On “Introduction to Reactive Programming”

> "FRP is programming with asynchronous data streams." Maybe, if you drop the F. For clarification on FRP there was a great talk at strangeloop this year: link to this video

michaelsbradleyon Hacker News • Recommends

On “React vs. Angular 2”

It's been around in various forms, and implemented on top of various languages, for quite some time. The earliest full-fledged FRP implementation for JavaScript was Flapjax – work on it dates all the way back to 2006! link The paper Flapjax: A Programming Language for Ajax Applications is worth reading. link The principal designer and maintainer of the Elm Language (a functional reactive lang that compiles to JS) did his Master's Thesis on FRP, and that's a great resource if you want the big picture: link See also Controlling Time and Space: understanding the many formulations of FRP , by the same author: link to this video

ghuntleyon Hacker News • Recommends

On “New Adventures for Elm”

For those just getting started in FRP or whom may have not seen the presentations at StangeLoop: - link to this video - Controlling Time and Space: understanding the many formulations of FRP by Evan Czaplicki (Elm language designer/Prezi) - link - FRP In Practice: Taking a look at ReactiveUI/Cocoa by Paul Betts (Slack/GitHub) - link - ReactiveUI - It's pretty neat by Brendan Forster (GitHub)

robewaldon Lobsters • Recommends

Controlling Time and Space: understanding the many formulations of FRP

u/gilmiin r/haskell • Mentions

FRP Systems discussion Haskell has many FRP libraries, every now and then another pops up. Can we have a discussion about the state of FRP in Haskell? for example: - What are the main differences between different FRP libraries and systems? - Do different systems fit different domains? - Do they make trade-offs to deal with performance problems or something like that? - Which FRP library do you recommend? why? - Do you think FRP is even interesting/important? Opinionated comments are welcomed! Some relevant links: - frp-zoo - [Controlling Time and Space: understanding the many formulations of FRP / Evan Czaplicki] - The Essence of FRP / Conal Elliott

u/kqrin r/haskell • Mentions

On “Are there ANY good game engines for haskell?”

Some background on the topic: pretty much all the existing game engines are *very* procedural or object-oriented in their design. This is of course possible to work with in Haskell, but it's not ideal. So there's been some research on how to make functional game engines, and one of the more promising approaches is called *functional reactive programming* which has a few implementations in Haskell. There's a presentation by Evan Czaplicki that gives a quick overview of three kinds of FRP. There are other approaches to the problem which I wish I knew more about, but alas I don't. My main point is that *we don't really know yet* what works best, which might explain why there hasn't been any…

u/Noughtmarein r/haskell • Mentions

On “What are different flavors of functional reactive programming?”

This video identifies four flavors: * first order (~~I think~~ elm used to use this ~~or maybe it still does~~) * higher order (Reflex, I think also reactive-banana) * asynchronous (mostly used outside Haskell) * arrowized (Yampa) Edit: The related work section of Ivan Perez Dominiguez (author of Yampa and dunai) "recent" PhD thesis (pdf) also contains lots of info.

u/meditansin r/haskell • Mentions

On “How to figure out which FRP library to use?”

Did you see Evan Czaplicki's presentation on the subject? link to this video

u/matthew_leonin r/haskell • Mentions

On “Amsden, A Survey of Functional Reactive Programming (2011)”

Also see Elm creator Evan Czaplicki's presentation: link to this video

u/k-bxin r/haskell • Mentions

On “FRP Systems discussion”

There's nice video ["Controlling Time and Space: understanding the many formulations of FRP" by Evan Czaplicki], which seems to explain differences by various FRP libraries. I'm not an expert and cannot comment how accurate it is (and which libraries choose which ways).

u/Mokoshain r/haskell • Mentions

On “Could someone elaborate on different FRP libraries? (as was the goal of this project)”

This video posted recently goes over a lot of the ideas behind current FRP implementations out there. Did you have any questions not covered?

u/Platzin r/haskell • Mentions

On “Conal Elliott's Push-Pull FRP?”

link to this video