Marionette

type Config msg sta = { exitIf :: msg -> sta -> Boolean, initialMsg :: Maybe msg, onEvent :: ProgramEvent msg sta -> Effect Unit, stateHandler :: sta -> Effect (State sta Aff) }

Type variables:

• msg the message type of your program
• sta the state type of your program

Record fields:

• exitIf provides an exit condition to leave the running state machine based on the current message/state combination.
• initialMsg useful if the first message event is not triggered by user input.
• onEvent lets you observe events that occur inside the marionette runtime. This is useful for either debugging or other kind of state machine flow analysis.
• stateHandler The state implementation that is used by the runtime.

data EventType msg sta

Possible observable events that may occur inside the marionette runtime.

Constructors

• NewMsg ThreadId msg

  new thread is triggered by a message event

• EndMsg ThreadId

  specific thread triggered by a message event has finished running

• NewState ThreadId sta

  new state update has been performed and a re-rendering was triggered

Instances

• Generic (EventType msg sta) _
• (Show msg, Show sta) => Show (EventType msg sta)

type Program msg sta = { controller :: Controller msg sta, initialState :: sta, renderer :: Renderer msg sta }

Type variables:

• msg message type of your program
• sta state type of your program

Record fields:

• initialState value of the initial state
• renderer specifies how state is rendered
• controller specifies the how the control flow is handled

data ProgramEvent msg sta

General program event type that contains a timestamp and a more specific event type.

Constructors

• ProgramEvent Instant (EventType msg sta)

Instances

• Generic (ProgramEvent msg sta) _
• (Show msg, Show sta) => Show (ProgramEvent msg sta)

newtype ThreadId

Every time a message is raised a new thread with an unique ThreadId is created that has read and write access to the program's state.

Constructors

• ThreadId Int

Instances

• Enum ThreadId
• Bounded ThreadId
• Ord ThreadId
• Eq ThreadId
• Semiring ThreadId
• Generic ThreadId _
• Show ThreadId

defaultConfig :: forall msg sta. Eq sta => Config msg sta

Some defaults for the Config type

noController :: forall msg sta. Controller msg sta

A controller that does nothing. Useful if you just want to render something and the controller is not implemented yet.

noRenderer :: forall msg sta. Renderer msg sta

A renderer that does nothing. Useful if like to run a headless state machine.

runProgram :: forall msg sta. Eq sta => Program msg sta -> Config msg sta -> Aff sta

Takes a stateful program specification and some configuration and runs the program in an Aff context.

Once the program has finished the final state is returned and all running threads are aborted.