Almost a year has passed since my previous answer and things have changed in the world of functional reactive programming (FRP). In particular, I have created reactive-banana, a small library for FRP in Haskell. While still missing some features, it’s already a great way to implement GUIs in a purely functional style, as demonstrated by … Read more
Unfortunately, I haven’t written any comprehensive documentation or tutorials yet, mainly because the reactive-banana library is still somewhat in flux. This means that, at the moment, you’ll have to figure things out yourself from various sources, backed by a reasonably strong Haskell knowledge. What I can do here is to list the various sources and … Read more
It’s easiest to understand with pictures: The first version repeat x = x : repeat x creates a chain of (:) constructors ending in a thunk which will replace itself with more constructors as you demand them. Thus, O(n) space. The second version repeat x = let xs = x : xs in xs uses … Read more
UPDATED: As William Harvey points out below, there is recent progress! Like you, I have an intense interest in the project, so I creep these pages every few weeks. 🙂 https://github.com/ingoem http://lamp.epfl.ch/~imaier/ https://codereview.scala-lang.org/fisheye/user/imaier https://lampsvn.epfl.ch/trac/scala/search?q=imaier
I think main problem is your assumption about the tackled problem are not quite so, since none of them are tackling the asynchronicity “problem”. The abstractions FRP main idea is propagation of change, think about accomplishing the same thing Excel does, where you define cells depending on each other in a cascade, and when one … Read more
I’m glad you’re starting by asking about a specification rather than implementation first. There are a lot of ideas floating around about what FRP is. From the very start in the early 90’s (when I was working in interactive graphics at Sun Microsystems and then Microsoft Research), it has been about two properties (a) denotative … Read more
How is reactive programming different than event-driven programming? Event driven programming revolves around so-called events, which are abstract things that programs “fire” when something happens. Other places in your code “listen” for the events and respond with what they need to do when that event happens. For instance, an event could be “user pressed this … Read more
I took a trip to Haskell.org to investigate your question What I found are two important papers you ought to read to further your research, and I am building my answer to your question from these scholarly papers. Push-Pull FRP by Conal Elliott Generalising Monads to Arrows by John Hughes Yes, but also no. According … Read more
If you want to get a feel for FRP, you could start with the old Fran tutorial from 1998, which has animated illustrations. For papers, start with Functional Reactive Animation and then follow up on links on the publications link on my home page and the FRP link on the Haskell wiki. Personally, I like … Read more