Control.Debounce

auto-update-0.1.4: Efficiently run periodic, on-demand actions

Safe Haskell | Safe
Language | Haskell2010

Control.Debounce

Contents

- Type
- Accessors
- Creation

Description

Debounce an action, ensuring it doesn't occur more than once for a given period of time.

This is useful as an optimization, for example to ensure that logs are only flushed to disk at most once per second.

Example usage:

    printString <- mkDebounce defaultDebounceSettings
                     { debounceAction = putStrLn "Running action"
                     , debounceFreq = 5000000 -- 5 seconds
                     }

    >>> printString
    Running action
    >>> printString
    <Wait five seconds>
    Running action

See the fast-logger package (System.Log.FastLogger) for real-world usage.

Since: 0.1.2

Synopsis

- data DebounceSettings
- defaultDebounceSettings :: DebounceSettings
- debounceFreq :: DebounceSettings -> Int
- debounceAction :: DebounceSettings -> IO ()
- mkDebounce :: DebounceSettings -> IO (IO ())

# Type

data DebounceSettings #

Settings to control how debouncing should work.

This should be constructed using `defaultDebounceSettings` and record update syntax, e.g.:

    let settings = defaultDebounceSettings { debounceAction = flushLog }

Since: 0.1.2

defaultDebounceSettings :: DebounceSettings #

Default value for creating a `DebounceSettings`.

Since: 0.1.2

# Accessors

debounceFreq :: DebounceSettings -> Int #

Microseconds lag required between subsequence calls to the debounced action.

Default: 1 second (1000000)

Since: 0.1.2

debounceAction :: DebounceSettings -> IO () #

Action to be performed.

Note: all exceptions thrown by this action will be silently discarded.

Default: does nothing.

Since: 0.1.2

# Creation

mkDebounce :: DebounceSettings -> IO (IO ()) #

Generate an action which will trigger the debounced action to be performed. The action will either be performed immediately, or after the current cooldown period has expired.

Since: 0.1.2