Haskell High Performance Programming

Combining events and behaviors

Events and behaviors are the core foundation of FRP in Reactive-banana. Behaviors can be composed via the Applicative interface, but numerous other ways are also provided by the Reactive-banana API. Some primitives are provided:

never :: Event a

unionWith
  :: (a -> a -> a) -> Event a  -> Event a -> Event a

filterE
  :: (a -> Bool) -> Event a -> Event a

apply
  :: Behavior (a -> b)  -> Event a -> Event b

It's apparent from the types what these functions do. unionWith combines two events using the first argument to decide the result in case of simultaneous emits. filterE suppresses events that don't match a predicate. apply applies a time-varying function to events. Often apply is encountered in its infix form, (<@>).

A special ...