FRP.Rhine.Schedule

Schedules are the compatibility mechanism between two different clocks. A schedule' implements the the universal clocks such that those two given clocks are its subclocks.

This module defines the Schedule type and certain general constructions of schedules, such as lifting along monad morphisms or time domain morphisms. It also supplies (sequential and parallel) compositions of clocks.

Specific implementations of schedules are found in submodules.

The schedule type

data Schedule m cl1 cl2

A schedule implements a combination of two clocks. It outputs a time stamp and an Either value, which specifies which of the two subclocks has ticked.

Constructors

Time cl1 ~ Time cl2 => Schedule

Fields

• initSchedule :: cl1 -> cl2 -> RunningClockInit m (Time cl1) (Either (Tag cl1) (Tag cl2))

Utilities to create new schedules from existing ones

hoistSchedule :: (Monad m1, Monad m2) => (forall a. m1 a -> m2 a) -> Schedule m1 cl1 cl2 -> Schedule m2 cl1 cl2

Lift a schedule along a monad morphism.

flipSchedule :: Monad m => Schedule m cl1 cl2 -> Schedule m cl2 cl1

Swaps the clocks for a given schedule.

rescaledSchedule :: Monad m => Schedule m cl1 cl2 -> Schedule m (RescaledClock cl1 time) (RescaledClock cl2 time)

If a schedule works for two clocks, a rescaling of the clocks also applies to the schedule.

rescaledScheduleS :: Monad m => Schedule m cl1 cl2 -> Schedule m (RescaledClockS m cl1 time tag1) (RescaledClockS m cl2 time tag2)

As rescaledSchedule, with a stateful rescaling

readerSchedule :: (Monad m, Clock (ReaderT r m) cl1, Clock (ReaderT r m) cl2, Time cl1 ~ Time cl2) => Schedule m (HoistClock (ReaderT r m) m cl1) (HoistClock (ReaderT r m) m cl2) -> Schedule (ReaderT r m) cl1 cl2

Lifts a schedule into the ReaderT transformer, supplying the same environment to its scheduled clocks.

Composite clocks

Sequentially combined clocks

data SequentialClock m cl1 cl2

Two clocks can be combined with a schedule as a clock for an asynchronous sequential composition of signal networks.

Constructors

(Time cl1 ~ Time cl2) => SequentialClock

Fields

• sequentialCl1 :: cl1
• sequentialCl2 :: cl2
• sequentialSchedule :: Schedule m cl1 cl2

Instances

(Monad m, Clock m cl1, Clock m cl2) => Clock m (SequentialClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

Associated Types

type Time (SequentialClock m cl1 cl2) :: *

type Tag (SequentialClock m cl1 cl2) :: *

Methods

initClock :: SequentialClock m cl1 cl2 -> RunningClockInit m (Time (SequentialClock m cl1 cl2)) (Tag (SequentialClock m cl1 cl2))

type Time (SequentialClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

type Time (SequentialClock m cl1 cl2) = Time cl1

type Tag (SequentialClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

type Tag (SequentialClock m cl1 cl2) = Either (Tag cl1) (Tag cl2)

type SeqClock m cl1 cl2 = SequentialClock m cl1 cl2

Abbrevation synonym.

schedSeq1 :: (Monad m, Semigroup cl1) => Schedule m cl1 (SequentialClock m cl1 cl2)

cl1 is a subclock of SequentialClock m cl1 cl2, therefore it is always possible to schedule these two clocks deterministically. The left subclock of the combined clock always ticks instantly after cl1.

schedSeq2 :: (Monad m, Semigroup cl2, Time cl1 ~ Time cl2) => Schedule m (SequentialClock m cl1 cl2) cl2

As schedSeq1, but for the right subclock. The right subclock of the combined clock always ticks instantly before cl2.

Parallelly combined clocks

data ParallelClock m cl1 cl2

Two clocks can be combined with a schedule as a clock for an asynchronous parallel composition of signal networks.

Constructors

(Time cl1 ~ Time cl2) => ParallelClock

Fields

• parallelCl1 :: cl1
• parallelCl2 :: cl2
• parallelSchedule :: Schedule m cl1 cl2

Instances

(Monad m, Clock m cl1, Clock m cl2) => Clock m (ParallelClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

Associated Types

type Time (ParallelClock m cl1 cl2) :: *

type Tag (ParallelClock m cl1 cl2) :: *

Methods

initClock :: ParallelClock m cl1 cl2 -> RunningClockInit m (Time (ParallelClock m cl1 cl2)) (Tag (ParallelClock m cl1 cl2))

type Time (ParallelClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

type Time (ParallelClock m cl1 cl2) = Time cl1

type Tag (ParallelClock m cl1 cl2)

Defined in FRP.Rhine.Schedule

type Tag (ParallelClock m cl1 cl2) = Either (Tag cl1) (Tag cl2)

type ParClock m cl1 cl2 = ParallelClock m cl1 cl2

Abbrevation synonym.

schedPar1 :: (Monad m, Semigroup cl1) => Schedule m cl1 (ParallelClock m cl1 cl2)

Like schedSeq1, but for parallel clocks. The left subclock of the combined clock always ticks instantly after cl1.

schedPar1' :: (Monad m, Semigroup cl1) => Schedule m cl1 (ParallelClock m cl1 cl2)

Like schedPar1, but the left subclock of the combined clock always ticks instantly before cl1.

schedPar2 :: (Monad m, Semigroup cl2, Time cl1 ~ Time cl2) => Schedule m (ParallelClock m cl1 cl2) cl2

Like schedPar1, but for the right subclock. The right subclock of the combined clock always ticks instantly before cl2.

schedPar2' :: (Monad m, Semigroup cl2, Time cl1 ~ Time cl2) => Schedule m (ParallelClock m cl1 cl2) cl2

Like schedPar1, but the right subclock of the combined clock always ticks instantly after cl2.

Navigating the clock tree

type family In cl where ...

The clock that represents the rate at which data enters the system.

Equations

In (SequentialClock m cl1 cl2) = In cl1

In (ParallelClock m cl1 cl2) = ParallelClock m (In cl1) (In cl2)

In cl = cl

type family Out cl where ...

The clock that represents the rate at which data leaves the system.

Equations

Out (SequentialClock m cl1 cl2) = Out cl2

Out (ParallelClock m cl1 cl2) = ParallelClock m (Out cl1) (Out cl2)

Out cl = cl

data LastTime cl where

A tree representing possible last times to which the constituents of a clock may have ticked.

Constructors

SequentialLastTime :: LastTime cl1 -> LastTime cl2 -> LastTime (SequentialClock m cl1 cl2)

ParallelLastTime :: LastTime cl1 -> LastTime cl2 -> LastTime (ParallelClock m cl1 cl2)

LeafLastTime :: Time cl -> LastTime cl

data ParClockInclusion clS cl where

An inclusion of a clock into a tree of parallel compositions of clocks.

Constructors

ParClockInL :: ParClockInclusion (ParallelClock m clL clR) cl -> ParClockInclusion clL cl

ParClockInR :: ParClockInclusion (ParallelClock m clL clR) cl -> ParClockInclusion clR cl

ParClockRefl :: ParClockInclusion cl cl

parClockTagInclusion :: ParClockInclusion clS cl -> Tag clS -> Tag cl

Generates a tag for the composite clock from a tag of a leaf clock, given a parallel clock inclusion.