Safe Haskell	Safe

Signal.Command

Synopsis

Documentation

data Command v Source

A signal triggered in response to some action, typically UI-related.

data CommandPolicy Source

Determines a command's behavior.

Constructors

ExecuteSerially	The command can only be executed once at a time. Attempts to `execute` while the command is already running will fail.
ExecuteConcurrently	The command can be executed concurrently any number of times.

Instances

Eq CommandPolicy
Show CommandPolicy

newCommand Source

Arguments

:: CommandPolicy	Determines how the command behaves when asked to `execute` multiple times simultaneously.
-> Signal MainScheduler Bool	A signal which sends whether the command should be enabled. `canExecute` will send `True` before this signal sends its first value.
-> SchedulerIO MainScheduler (Command v)

Creates a command.

canExecute :: Command v -> Signal MainScheduler Bool Source

Sends whether this command is able to execute.

This signal will always send at least one value immediately upon subscription.

executing :: Command v -> Signal MainScheduler Bool Source

Sends whether this command is currently executing.

This signal will always send at least one value immediately upon subscription.

execute Source

Arguments

:: Command v	The command to execute.
-> v	A value to send to the command's subscribers.
-> SchedulerIO MainScheduler Bool	Whether execution succeeded. This will be `False` if the command is disabled.

Attempts to execute a command.

values :: Command v -> Signal MainScheduler vSource

A signal of the values passed to execute.

onExecute Source

Arguments

:: Command v	The command to attach behavior to.
-> (v -> Signal BackgroundScheduler ())	A function which maps from the command's values to a signal of side-effecting work.
-> SchedulerIO MainScheduler (Signal MainScheduler (Signal BackgroundScheduler ()))	A signal of the created signals.

Creates a signal whenever the command executes, then subscribes to it.

errors :: Command v -> Signal MainScheduler IOException Source

A signal of errors received from all signals created by onExecute.

type Channel s v = (Subscriber s v, Signal s v)Source

A controllable signal, represented by a Subscriber and Signal pair.

Values sent to the subscriber will automatically be broadcast to all of the signal's subscribers. In effect, the subscriber is the write end, while the signal is the read end.

data Signal s v Source

A signal which will send values of type v on a scheduler of type s.

Instances

Scheduler s => Monad (Signal s)
Scheduler s => Functor (Signal s)
Scheduler s => MonadPlus (Signal s)
Scheduler s => Applicative (Signal s)
Scheduler s => MonadZip (Signal s)
Scheduler s => Monoid (Signal s v)

class Scheduler s Source

Represents a queue of IO actions which can be executed in FIFO order.

Instances

Scheduler BackgroundScheduler
Scheduler MainScheduler

data SchedulerIO s a Source

An IO computation that must be performed in a scheduler of type s.

Instances

Scheduler s => Monad (SchedulerIO s)
Functor (SchedulerIO s)
Scheduler s => Applicative (SchedulerIO s)
Scheduler s => MonadIO (SchedulerIO s)
Show v => Show (SchedulerIO BackgroundScheduler v)
Show v => Show (SchedulerIO MainScheduler v)	Unsafely executes a `SchedulerIO` action and shows the result. This is for DEBUGGING PURPOSES ONLY.

data BackgroundScheduler Source

A scheduler which runs enqueued actions in a dedicated background thread.

Instances

Scheduler BackgroundScheduler
Show v => Show (SchedulerIO BackgroundScheduler v)

data MainScheduler Source

A scheduler which runs enqueued actions on the main thread.

Instances

Scheduler MainScheduler
Show v => Show (SchedulerIO MainScheduler v)	Unsafely executes a `SchedulerIO` action and shows the result. This is for DEBUGGING PURPOSES ONLY.