FRP.Yampa.Basic

Basic signal functions

identity :: SF a a

Identity: identity = arr id

Using identity is preferred over lifting id, since the arrow combinators know how to optimise certain networks based on the transformations being applied.

constant :: b -> SF a b

Identity: constant b = arr (const b)

Using constant is preferred over lifting const, since the arrow combinators know how to optimise certain networks based on the transformations being applied.

Initialization

(-->) :: b -> SF a b -> SF a b infixr 0

Initialization operator (cf. Lustre/Lucid Synchrone).

The output at time zero is the first argument, and from that point on it behaves like the signal function passed as second argument.

(>--) :: a -> SF a b -> SF a b infixr 0

Input initialization operator.

The input at time zero is the first argument, and from that point on it behaves like the signal function passed as second argument.

(-=>) :: (b -> b) -> SF a b -> SF a b infixr 0

Transform initial output value.

Applies a transformation f only to the first output value at time zero.

(>=-) :: (a -> a) -> SF a b -> SF a b infixr 0

Transform initial input value.

Applies a transformation f only to the first input value at time zero.

initially :: a -> SF a a

Override initial value of input signal.