Data.Recursive.Propagator.P2

A propagator for the two-point lattice

Documentation

data P2

A type for propagators for the two-point lattice, consisting of bottom and top

newP2 :: IO P2

A new propagator, initialized at bottom

newTopP2 :: IO P2

A new propagator, already set to top

setTop :: P2 -> IO ()

Set a propagator to top.

If it was bottom before, runs the actions queued with whenTop. It does so _after_ setting the propagator to top, so that cycles are broken.

whenTop :: P2 -> IO () -> IO ()

whenTop p act runs act if p is already top, or after setTop p is run

implies :: P2 -> P2 -> IO ()

p1 implies p2 chains propagators: If p1 becomes top, then so does p2.

isTop :: P2 -> IO Bool

Queries the current state of the propagator. All related calls to setTop that have executed so far are taken into account.

newtype PBool

A newtype around P2 to denote that bottom is False and top is True

Constructors

PBool P2

Instances

Propagator PBool Bool

Defined in Data.Recursive.Propagator.Class

Methods

newProp :: IO PBool

newConstProp :: Bool -> IO PBool

readProp :: PBool -> IO Bool

newtype PDualBool

A newtype around P2 to denote that bottom is True and top is False

Constructors

PDualBool P2

Instances

Propagator PDualBool (Dual Bool)

Defined in Data.Recursive.Propagator.Class

Methods

newProp :: IO PDualBool

newConstProp :: Dual Bool -> IO PDualBool

readProp :: PDualBool -> IO (Dual Bool)