reactive: Push-pull functional reactive programming

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Reactive is a simple foundation for programming reactive systems functionally. Like Fran/FRP, it has a notions of (reactive) behaviors and events. Unlike most previous FRP implementations, Reactive has a hybrid demand/data-driven implementation, as described in the paper "Push-pull functional reactive programming",

This version of Reactive has some serious bugs that show up particularly with some uses of the Event monad. Some problems have been due to bugs in the GHC run-time support for concurrency. I do not know whether the remaining problems in Reactive are still more subtle RTS issues, or some subtle laziness bugs in Reactive. Help probing the remaining difficulties is most welcome.

Import FRP.Reactive for FRP client apps. To make a Reactive adapter for an imperative library, import FRP.Reactive.LegacyAdapters.

Please see the project wiki page:

© 2007-2009 by Conal Elliott; GNU AGPLv3 license (see COPYING). I am not thrilled with GPL, and I doubt I'll stay with it for long. If you would like different terms, please talk to me.

With contributions from: Robin Green, Thomas Davie, Luke Palmer, David Sankel, Jules Bean, Creighton Hogg, Chuan-kai Lin, and Richard Smith. Please let me know if I've forgotten to list you.

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Versions [RSS] 0.0, 0.2, 0.3, 0.5,, 0.8.3, 0.8.6, 0.8.8, 0.9.0, 0.9.1, 0.9.3, 0.9.4, 0.9.5, 0.9.6, 0.9.7, 0.9.8, 0.9.9, 0.9.10, 0.10.0, 0.10.1, 0.10.2, 0.10.3, 0.10.4, 0.10.5, 0.10.7, 0.11, 0.11.2, 0.11.3, 0.11.4, 0.11.5
Dependencies base (>=4 && <5), category-extras (>=0.53.5), checkers (>=0.2.3), old-time, QuickCheck (>=, random, Stream (>=0.3.1), TypeCompose (>=0.8.0), unamb (>=0.1.5), vector-space (>=0.5) [details]
License LicenseRef-OtherLicense
Copyright (c) 2007-2009 by Conal Elliott
Author Conal Elliott
Category reactivity, FRP
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Uploaded by ConalElliott at 2010-07-28T16:49:12Z
Reverse Dependencies 4 direct, 4 indirect [details]
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Readme for reactive-0.11.5

[back to package description]
_Reactive_ [1] is a simple foundation for programming reactive systems
functionally.  Like Fran/FRP, it has a notions of (reactive) behaviors and
events.  Like DataDriven [2], Reactive has a data-driven implementation.

The inspiration for Reactive was Mike Sperber's Lula [3] implementation of
FRP.  Mike used blocking threads, which I had never considered for FRP.
While playing with the idea, I realized that I could give a very elegant
and efficient solution to caching, which DataDriven doesn't do.  (For an
application "f <*> a" of a varying function to a varying argument, caching
remembers the latest function to apply to a new argument and the last
argument to which to apply a new function.)

The theory and implementation of Reactive are described in the paper
"Push-pull functional reactive programming" [4].

Note that cabal[5], version or greater is required for installation.

You can configure, build, and install all in the usual way with Cabal

  runhaskell Setup.lhs configure
  runhaskell Setup.lhs build
  runhaskell Setup.lhs install