Control.Wire.Switch

Simple switching

(-->) :: Monad m => Wire s e m a b -> Wire s e m a b -> Wire s e m a b infixr 1

Acts like the first wire until it inhibits, then switches to the second wire. Infixr 1.

• Depends: like current wire.
• Inhibits: after switching like the second wire.
• Switch: now.

(>--) :: Monad m => Wire s e m a b -> Wire s e m a b -> Wire s e m a b infixr 1

Acts like the first wire until the second starts producing, at which point it switches to the second wire. Infixr 1.

• Depends: like current wire.
• Inhibits: after switching like the second wire.
• Switch: now.

Context switching

modes

Arguments

:: (Monad m, Ord k)

=> k

Initial mode.

-> (k -> Wire s e m a b)

Select wire for given mode.

-> Wire s e m (a, Event k) b

Route the left input signal based on the current mode. The right input signal can be used to change the current mode. When switching away from a mode and then switching back to it, it will be resumed. Freezes time during inactivity.

• Complexity: O(n * log n) space, O(log n) lookup time on switch wrt number of started, inactive modes.
• Depends: like currently active wire (left), now (right).
• Inhibits: when active wire inhibits.
• Switch: now on mode change.

Event-based switching

Intrinsic

switch :: (Monad m, Monoid s) => Wire s e m a (b, Event (Wire s e m a b)) -> Wire s e m a b

Intrinsic switch: Start with the given wire. As soon as its event occurs, switch to the wire in the event's value.

• Inhibits: like argument wire until switch, then like the new wire.
• Switch: once, now, restart state.

dSwitch :: Monad m => Wire s e m a (b, Event (Wire s e m a b)) -> Wire s e m a b

Intrinsic switch: Delayed version of switch.

• Inhibits: like argument wire until switch, then like the new wire.
• Switch: once, after now, restart state.

Intrinsic continuable

kSwitch :: (Monad m, Monoid s) => Wire s e m a b -> Wire s e m (a, b) (Event (Wire s e m a b -> Wire s e m a b)) -> Wire s e m a b

Intrinsic continuable switch: kSwitch w1 w2 starts with w1. Its signal is received by w2, which may choose to switch to a new wire. Passes the wire we are switching away from to the new wire, such that it may be reused in it.

• Inhibits: like the first argument wire, like the new wire after switch. Inhibition of the second argument wire is ignored.
• Switch: once, now, restart state.

dkSwitch :: Monad m => Wire s e m a b -> Wire s e m (a, b) (Event (Wire s e m a b -> Wire s e m a b)) -> Wire s e m a b

Intrinsic continuable switch: Delayed version of kSwitch.

• Inhibits: like the first argument wire, like the new wire after switch. Inhibition of the second argument wire is ignored.
• Switch: once, after now, restart state.

Extrinsic

rSwitch :: Monad m => Wire s e m a b -> Wire s e m (a, Event (Wire s e m a b)) b

Extrinsic switch: Start with the given wire. Each time the input event occurs, switch to the wire it carries.

• Inhibits: like the current wire.
• Switch: recurrent, now, restart state.

drSwitch :: Monad m => Wire s e m a b -> Wire s e m (a, Event (Wire s e m a b)) b

Extrinsic switch: Delayed version of rSwitch.

• Inhibits: like the current wire.
• Switch: recurrent, after now, restart state.

alternate :: Monad m => Wire s e m a b -> Wire s e m a b -> Wire s e m (a, Event x) b

Acts like the first wire until an event occurs then switches to the second wire. Behaves like this wire until the event occurs at which point a *new* instance of the first wire is switched to.

• Depends: like current wire.
• Inhibits: like the argument wires.
• Switch: once, now, restart state.

Extrinsic continuable

krSwitch :: Monad m => Wire s e m a b -> Wire s e m (a, Event (Wire s e m a b -> Wire s e m a b)) b

Extrinsic continuable switch. This switch works like rSwitch, except that it passes the wire we are switching away from to the new wire.

• Inhibits: like the current wire.
• Switch: recurrent, now, restart state.

dkrSwitch :: Monad m => Wire s e m a b -> Wire s e m (a, Event (Wire s e m a b -> Wire s e m a b)) b

Extrinsic continuable switch. Delayed version of krSwitch.

• Inhibits: like the current wire.
• Switch: recurrent, after now, restart state.