motor-reflection: Reflect on Motor FSM typeclasses to obtain runtime representations

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Reflect on Motor FSM typeclasses to obtain runtime representations.

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Properties

Versions	0.2.0.0, 0.3.0, 0.4.0, 0.4.0
Change log	CHANGELOG.md
Dependencies	base (>=4.9 && <5), motor (>=0.4.0), template-haskell (>=2.11.1.0), text [details]
License	MPL-2.0
Copyright	Oskar Wickström
Author	Oskar Wickström
Maintainer	oskar.wickstrom@gmail.com
Category	Control
Source repo	head: git clone https://github.com/owickstrom/motor
Uploaded	by owickstrom at 2019-06-28T05:57:03Z

Modules

[Index] [Quick Jump]

Motor
- FSM
  - Motor.FSM.Reflection
    - Motor.FSM.Reflection.Event

Downloads

motor-reflection-0.4.0.tar.gz [browse] (Cabal source package)
Package description (as included in the package)

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Package maintainers

owickstrom

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Readme for motor-reflection-0.4.0

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motor-reflection

Reflect on typeclasses following Motor FSM conventions, using Template Haskell.

This package is experimental!

Usage

First, you need to import the reflection module and the Event type:

import           Motor.FSM.Reflection
import           Motor.FSM.Reflection.Event (Event)

Given that your FSM typeclass follows Motor's conventions, you can reflect to get a list of events:

data Open
data Closed

class MonadFSM m => Door (m :: Row * -> Row * -> * -> *) where
  type State m :: * -> *
  initial
    :: Name n
    -> Actions m '[n !+ State m Open] r ()
  close
    :: Name n
    -> Actions m '[n :-> State m Open !--> State m Closed] r ()
  open
    :: Name n
    -> Actions m '[n :-> State m Closed !--> State m Open] r ()
  end
    :: Name n
    -> Actions m '[n !- State m Closed] r ()

reflectEvents ''Door "doorEvents"

The last line, using reflectEvents, will define doorEvents :: [Motor.FSM.Reflection.Event.Event] at the top-level.

Conventions

The typeclass must have an associated type (open type family) called State, parameterized by the instance, with a result of kind * -> *.
Each FSM event in the typeclass must have a return type of the Actions type alias, listing the additions, deletions, and transitions of named resources.

These conventions may be relaxed in the future. This package is new and experimental.

License

Mozilla Public License Version 2.0, see LICENSE file in each package.