Hello there, Netwire 3.0.0 is out: http://hackage.haskell.org/package/netwire Overview -------- Netwire is a library for high performance functional reactive programming, which calls its signal functions 'wires'. It solves the classic problems of FRP through a number of simple concepts: * It is based on an automaton arrow (similar to Yampa), so performance problems like time leaks become local. Getting high FRP performance is the art of writing good primitive automata, which is simple enough. * Wire inhibition (ArrowZero), combination (ArrowPlus) and choice (ArrowChoice) make switching combinators entirely obsolete. * Events are based on inhibition, so non-happened events take no CPU time. * Very simple internal representation: Writing custom primitive wires is easy. Since Netwire is developed mainly with libraries in mind, its internals are exposed entirely. If you need a wire that is not predefined, just write an addon. * Finally Netwire comes with a large set of predefined wires. This new version comes along with a major API change (hence the new major version number) -- hopefully the last one. The main change is that the Wire type is now a data family. This gives the flexibility of Netwire 2 with the high performance of Netwire 1. We are back to 600k FPS now for moderately complicated wires. =) Changes ------- Major changes and new features include: * Wire is now a data family. Most wire features are now addons through type classes, and every arrow can provide its own version of them, which is optimized for their respective internal representation. Mainly you get back the high performance monad-based wires from Netwire 1. * Nondeterministic wires (see below). * New wire transformers for supplying a clock, concurrent wires, and memoization/caching. * Improved ArrowLoop instance: Inhibition is now allowed inside of 'rec', as long as it doesn't break data dependencies. If it does, you get a useful error message now instead of a fatal pattern match failure. Minor changes: * Measuring FPS without disturbing performance: avgFpsInt. * The 'execute' wire is back. * More convenient wire stepping and testing functions. * Often you don't care about an event's value: gotEvent. Nondeterministic wires ---------------------- Now that Wire is a data family, you can have efficient nondeterministic wires by using a Kleisli-wrapped logic monad as the base arrow: import Control.Monad.Logic type MyWire = Wire e (Kleisli (LogicT IO)) Now you can use branching in a MyWire computation: x <- swallow branch -< [1..100] This will split the wire session into 101 branches at the first instant (it will always branch into a single inhibiting wire). Suppose you have an HTTP bot. You can now read URLs from a file and branch into an own wire for each URL: url <- swallow (branch <<< execute) -< fmap lines (readFile "urls.txt") quitWith <<< myBot -< url Performance ----------- Netwire 3 easily outperforms Netwire 2 by a factor of 10-30. Usually you will work with wire arrows on top of a Kleisli arrow. Now that Wire is a data family you can have an efficient representation of that, which gets along entirely without the Kleisli constructor wrapping. Now the main bottleneck is the monadic actions performed. This is very satisfactory. Greets, Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://ertes.de/