Motor.FSM.Sugar

Syntactic sugar for MonadFSM types, adding appropriate row constraints and hiding complexity of the internal implementation.

Documentation

data Action

An Action describes a resource action.

Constructors

Add Type

Adds a new resource of the given Type.

Remain Type

The existing resource of the given Type remains the same.

To Type Type

Transitions an existing resource from the first Type to a resource of the second Type.

Delete Type

Deletes an existing resource of the given Type.

data ActionMapping

Mapping from Symbol to some action a.

Constructors

(:=) Symbol Action infixr 5

type family FromActions (as :: [ActionMapping]) (rs :: Row *) (c :: Constraint) :: (Row *, Constraint) where ...

Translates a list of Actions to a Row.

Equations

FromActions '[] rs c = '(rs, c)

FromActions ((n := Add a) ': ts) r c = FromActions ts (Extend n a r) (c, (Extend n a r .! n) ~ a)

FromActions ((n := Delete a) ': ts) r c = FromActions ts (r .- n) (c, (r .! n) ~ a)

FromActions ((n := To a b) ': ts) r c = FromActions ts (Modify n b r) (c, (r .! n) ~ a, (Modify n b r .! n) ~ b)

FromActions ((n := Remain a) ': ts) r c = FromActions ts r (c, (r .! n) ~ a)

type NoActions m (r :: Row *) a = m r r a

Alias for MonadFSM that includes no actions.

type Actions m as (i :: Row *) a = forall o c. (FromActions as i NoConstraint ~ '(o, c), c) => m i o a

Alias for MonadFSM that uses FromActions to construct rows.

type OnlyActions m as a = Actions m as Empty a

Alias for MonadFSM that uses FromActions to construct rows, starting from an Empty row, i.e. allowing no other resources.

type Get m (r :: Row *) n = m r r (r .! n)

Gets an existing resource in state s.

type (!-->) i o = To i o infixl 6

Infix version of To.

type (!+) (n :: Symbol) s = n := Add s infix 6

Add a named resource. Alias of Add.

type (!-) (n :: Symbol) s = n := Delete s infix 6

Delete a named resource. Alias of Delete.