Functional Reactive Programming

1. FRP
Functional Reactive Programming

2. – Conal Elliott and Paul Hudak [1997]
“Functional Reactive Animation”

3. Philip Roberts: Enemy of the state:An introduction to Functional
Reactive Programming and Bacon.js

4. BITCH PLEASE

5. TL;DR

6. TERMINOLOGY
• Observer (Observable)
• EventStream
• Behaviour
• Signal

7. INTERFACE
/**
* Represents a push-style collection.
*/
function Observable(subscribe) {
this.subscribe = subscribe;
};
Observable.prototype.subscribe = function(onNext, onError, onCompleted) {};
/**
* Supports push-style iteration over an observable sequence.
*/
function Observer(onNext, onError, onCompleted) {
this.onNext = onNext;
this.onError = onError;
this.onCompleted = onCompleted;
}
Observer.prototype.onNext = function(value) {};
Observer.prototype.onError = function(exception) {};
Observer.prototype.onCompleted = function() {};

8. RXJS
The Reactive Extensions for
JavaScript

9. BACON.JS
The most delicious JavaScript
library

10. Feature RxJS Bacon.js
Creating an observable sequence ✓ ✓
Converting events or asynchronous patterns to observable sequences, or between
Arrays and observable sequences. ✓ ✓
Combining multiple observable sequences into a single sequence. ✓ ✓
Functional ✓ ✗
Mathemathical operators on sequences ✓ ✗
Time-based operations ✓ ✓
Handling Exceptions ✓ ✗
Filtering and selecting values in a sequence ✓ ✓
Grouping and Windowing ✓ ✓
Imperative Operators ✓ ✗
Primitives ✓ ✓

11. THAT’S IT?
• Async.js is a clean, composable way to manipulate
sequences of values with asynchronous functions
• Flapjax is a new programming language designed around
the demands of modern, client-based Web applications
• Javelin is a spreadsheet-like dataflow programming in
ClojureScript
• And lots of wrappers around everything…

12. DEMO

13. README
Libraries:
• http://reactive-extensions.github.io/RxJS/
• http://baconjs.github.io/
• https://github.com/fjakobs/async.js
!
Courses:
• https://coursera.org/course/reactive
!
Videos:
• http://vimeo.com/68987289
!
Papers:
• http://conal.net/papers/icfp97/
• http://conal.net/fran/tutorial.htm

14. THANKS