cron.lua/README.textile

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h1. cron.lua
@cron.lua@ are a set of functions for executing actions at a certain time interval.
h1. Examples of use
* @cron.after(time, callback)@ will execute callback after the given amount of time units. Returns an identifier (@id@)
* @cron.every(time, callback)@ will repeat the same action periodically. Returns an identifier (@id@)
* @cron.cancel(id)@ will stop a timed action from happening, and will interrupt the periodical execution of a periodic action.
* @cron.reset()@ removes all timed and periodic actions, and resets the time passed back to 0.
* @cron.update(dt)@ is needed to be executed on the main program loop. @dt@ is the amount of time that has passed since the last iteration. When @cron.update@ is executed, cron will check the list of pending actions and execute them if needed.
* @cron.tagged(tag1, tag2, tag3 ...)@ filters other cron methods (@cron.after@, @cron.every@, @cron.update@ & @cron.cancel@ but not @cron.reset@) so that they create clocks with specific tags/ act on clocks with specific tags.
<pre>
local cron = require 'cron'
local function printMessage()
print('Hello')
end
-- the following calls are equivalent:
cron.after(5, printMessage)
cron.after(5, print, 'Hello')
cron.update(5) -- will print 'Hello' twice
-- this will print the message periodically:
local id = cron.every(10, printMessage)
cron.update(5) -- nothing
cron.update(4) -- nothing
cron.update(12) -- prints 'Hello' twice
cron.cancel(id) -- stops the execution the element defined by id. Works with periodical or one-time actions.
cron.reset() -- stops all the current actions, both timed ones and periodical ones.
</pre>
Some tag examples:
<pre>
-- This has the same effect of cron.after(2, showMenu), except that the
-- time entry is tagged with the tags 'main-menu' and 'menu'
cron.tagged('main-menu', 'menu').after(2, showMenu)
-- This updates the time entries tagged with the tag 'menu', but not the rest
cron.tagged('menu').update(2)
-- cron.cancel does not admit filtering via tags, but it admits tags as params
-- the previous call is equivalent to this one:
cron.tagged('main-menu').cancel()
</pre>
h1. Gotchas / Warnings
* @cron.lua@ does *not* implement any hardware or software clock; you will have to provide it with the access to the hardware timers, in the form of periodic calls to @cron.update@
* @cron@ does not have any defined time units (seconds, milliseconds, etc). You define the units it uses by passing it a @dt@ on @cron.update@. If @dt@ is in seconds, then @cron@ will work in seconds. If @dt@ is in milliseconds, then @cron@ will work in milliseconds.
h1. Installation
Just copy the cron.lua file somewhere in your projects (maybe inside a /lib/ folder) and require it accordingly.
Remember to store the value returned by require somewhere! (I suggest a local variable named @cron@)
<pre>
local cron = require 'cron'
</pre>
Also, make sure to read the license file; the text of that license file must appear somewhere in your projects' files.
h1. Specs
This project uses "telescope":https://github.com/norman/telescope for its specs. If you want to run the specs, you will have to install telescope first. Then run:
<pre>
tsc spec/*
</pre>