Control.FRPNow.Time

Various utility functions for FRPNow related to the passing of time. All take a "clock" as an argument, i.e. a behavior that gives the seconds since the program started.

The clock itself is created by a function specialized to the GUI library you are using FRP with such as getClock

Documentation

localTime :: (Floating time, Ord time) => Behavior time -> Behavior (Behavior time)

When sampled at time t, gives the time since time t

timeFrac :: (Floating time, Ord time) => Behavior time -> time -> Behavior (Behavior time)

Gives a behavior that linearly increases from 0 to 1 in the specified duration

lastInputs

Arguments

:: (Floating time, Ord time)

=> Behavior time

The "clock" behavior, the behavior monotonically increases with time

-> time

The duration of the history to be kept

-> EvStream a

The input stream

-> Behavior (Behavior [a])

Gives a behavior containing the values of the events in the stream that occured in the last n seconds

bufferBehavior

Arguments

:: (Floating time, Ord time)

=> Behavior time

The "clock" behavior, the behavior monotonically increases with time

-> time

The duration of the history to be kept

-> Behavior a

The input behavior

-> Behavior (Behavior [(time, a)])

Gives a behavior containing the values of the behavior during the last n seconds, with time stamps

delayBy

Arguments

:: (Floating time, Ord time)

=> Behavior time

The "clock" behavior, the behavior monotonically increases with time

-> time

The duration of the delay

-> Behavior a

The input behavior

-> Behavior (Behavior a)

Give a version of the behavior delayed by n seconds

delayByN

Arguments

:: (Floating time, Ord time)

=> Behavior time

The "clock" behavior, the behavior monotonically increases with time

-> time

The duration _between_ delayed versions

-> Integer

The number of delayed versions

-> Behavior a

The input behavior

-> Behavior (Behavior [a])

Give n delayed versions of the behavior, each with the given duration in delay between them.

delayTime :: Eq time => Behavior time -> a -> Behavior a -> Behavior (Behavior a)

Delay a behavior by one tick of the clock. Occasionally useful to prevent immediate feedback loops. Like delay, but uses the changes of the clock as an event stream.

integrate :: VectorSpace v time => Behavior time -> Behavior v -> Behavior (Behavior v)

Integration using rectangle rule approximation. Integration depends on when we start integrating so the result is Behavior (Behavior v).

class (Eq a, Eq v, Ord v, Ord a, Floating a) => VectorSpace v a | v -> a where

A type class for vector spaces. Stolen from Yampa. Thanks Henrik :)

Minimal complete definition

zeroVector, (*^), (^+^), dot

Methods

zeroVector :: v

(*^) :: a -> v -> v infixr 9

(^/) :: v -> a -> v infixl 9

negateVector :: v -> v

(^+^) :: v -> v -> v infixl 6

(^-^) :: v -> v -> v infixl 6

dot :: v -> v -> a infix 7

norm :: v -> a

normalize :: v -> v

Instances

VectorSpace Double Double

VectorSpace Float Float

(Eq a, Floating a, Ord a) => VectorSpace (a, a) a

(Eq a, Floating a, Ord a) => VectorSpace (a, a, a) a

(Eq a, Floating a, Ord a) => VectorSpace (a, a, a, a) a

(Eq a, Floating a, Ord a) => VectorSpace (a, a, a, a, a) a