Control.Arrow.Machine.Utils

AFRP-like utilities

hold :: ArrowApply a => b -> ProcessA a (Event b) b

accum :: ArrowApply a => b -> ProcessA a (Event (b -> b)) b

edge :: (ArrowApply a, Eq b) => ProcessA a b (Event b)

passRecent :: (ArrowApply a, Occasional o) => ProcessA a (AS e) (Event b) -> ProcessA a (e, AS b) o -> ProcessA a (AS e) o infixr 9

Deprecated: Use hold instead

withRecent :: (ArrowApply a, Occasional o) => ProcessA a (e, AS b) o -> ProcessA a (e, AS (Event b)) o

Deprecated: Use hold instead

Switches

Switches inspired by Yampa library. Signature is almost same, but collection requirement is not only Functor, but Traversable. This is because of side effects.

switch :: ArrowApply a => ProcessA a b (c, Event t) -> (t -> ProcessA a b c) -> ProcessA a b c

dSwitch :: ArrowApply a => ProcessA a b (c, Event t) -> (t -> ProcessA a b c) -> ProcessA a b c

rSwitch :: ArrowApply a => ProcessA a b c -> ProcessA a (b, Event (ProcessA a b c)) c

drSwitch :: ArrowApply a => ProcessA a b c -> ProcessA a (b, Event (ProcessA a b c)) c

kSwitch :: ArrowApply a => ProcessA a b c -> ProcessA a (b, c) (Event t) -> (ProcessA a b c -> t -> ProcessA a b c) -> ProcessA a b c

dkSwitch :: ArrowApply a => ProcessA a b c -> ProcessA a (b, c) (Event t) -> (ProcessA a b c -> t -> ProcessA a b c) -> ProcessA a b c

pSwitch :: (ArrowApply a, Traversable col) => (forall sf. b -> col sf -> col (ext, sf)) -> col (ProcessA a ext c) -> ProcessA a (b, col c) (Event mng) -> (col (ProcessA a ext c) -> mng -> ProcessA a b (col c)) -> ProcessA a b (col c)

pSwitchB :: (ArrowApply a, Traversable col) => col (ProcessA a b c) -> ProcessA a (b, col c) (Event mng) -> (col (ProcessA a b c) -> mng -> ProcessA a b (col c)) -> ProcessA a b (col c)

rpSwitch :: (ArrowApply a, Traversable col) => (forall sf. b -> col sf -> col (ext, sf)) -> col (ProcessA a ext c) -> ProcessA a (b, Event (col (ProcessA a ext c) -> col (ProcessA a ext c))) (col c)

rpSwitchB :: (ArrowApply a, Traversable col) => col (ProcessA a b c) -> ProcessA a (b, Event (col (ProcessA a b c) -> col (ProcessA a b c))) (col c)

State arrow

peekState :: (ArrowApply a, ArrowState s a) => ProcessA a e s

encloseState :: (ArrowApply a, ArrowApply a', ArrowAddState s a a') => ProcessA a b c -> s -> ProcessA a' b c

Other utility arrows

tee :: ArrowApply a => ProcessA a (Event b1, Event b2) (Event (Either b1 b2))

Make two event streams into one. Actually gather is more general and convenient;

... <- tee -< (e1, e2)

is equivalent to

... <- gather -< [Left <$> e1, Right <$> e2]

gather :: (ArrowApply a, Foldable f) => ProcessA a (f (Event b)) (Event b)

Make multiple event channels into one. If simultaneous events are given, lefter one is emitted earlier.

sample :: ArrowApply a => ProcessA a (Event b1, Event b2) [b1]

source :: (ArrowApply a, Foldable f) => f c -> ProcessA a (Event b) (Event c)

Provides a source event stream. A dummy input event stream is needed.

  run af [...]

is equivalent to

  run (source [...] >>> af) (repeat ())

fork :: (ArrowApply a, Foldable f) => ProcessA a (Event (f b)) (Event b)

Given an array-valued event and emit it's values as inidvidual events.

filter :: ArrowApply a => a b Bool -> ProcessA a (Event b) (Event b)

echo :: ArrowApply a => ProcessA a (Event b) (Event b)

anytime :: ArrowApply a => a b c -> ProcessA a (Event b) (Event c)

Executes an action once per an input event is provided.

par :: (ArrowApply a, Traversable col) => (forall sf. b -> col sf -> col (ext, sf)) -> col (ProcessA a ext c) -> ProcessA a b (col c)

parB :: (ArrowApply a, Traversable col) => col (ProcessA a b c) -> ProcessA a b (col c)

now :: ArrowApply a => ProcessA a b (Event ())

onEnd :: (ArrowApply a, Occasional' b) => ProcessA a b (Event ())

cycleDelay :: ArrowApply a => ProcessA a b b

Observe a previous value of a signal. Tipically used with rec statement.