Huge thanks to JavaCafe for the demo GIF :)
Installation:
sudo luarocks --lua-version 5.3 install awestore
This library is built off the concept of stores from Svelte. A store is a simple table that can be subscribed to, notifying interested parties whenever the stored value changes. Heres simple example:
local awestore = require "awestore"
local my_store = awestore.writable(1)
my_store:subscribe(function(v) print(v); end) -- prints "1"
my_store:set(2) -- prints "2"
subscribe
returns an unsubscriber function, which when called, unregisters
the function registered using subscribe
. This is necessary for garbage
collection of upvalues captured by the registered functions.
local awestore = require "awestore"
local my_store = awestore.writable(1)
local unsubscriber = my_store:subscribe(function(v) print(v); end) -- prints "1"
my_store:set(2) -- prints "2"
unsubscriber()
my_store:set(3) -- prints nothing
To create a read-only version of a writable
store, you can use a monitored
store:
local awestore = require "awestore"
local my_writable_store = awestore.writable(1)
local my_monitored_store = awestore.monitored(my_writable_store) -- or my_writable_store:monitor()
my_monitored_store:subscribe(function(v) print(v); end) -- prints "1"
my_store:set(2) -- prints "2"
assert(type(my_writable_store.set) == "function")
assert(type(my_monitored_store.set) == "nil")
To alter the output of a store and forward it on, you can use a derived
store:
local awestore = require "awestore"
local my_writable_store = awestore.writable(1)
local my_derived_store = awestore.derived(my_writable_store, function(v)
return v ^ v
end) -- or my_writable_store:derive(fn)
my_derived_store:subscribe(function(v) print(v); end) -- prints "1"
my_store:set(2) -- prints "4"
my_store:set(3) -- prints "27"
assert(type(my_writable_store.set) == "function")
assert(type(my_monitor_store.set) == "nil")
Similarly, to only pass forward select outputs of a store, you can use a
filtered
store:
local awestore = require "awestore"
local my_writable_store = awestore.writable(1)
local my_filtered_store = awestore.filtered(my_writable_store, function(v)
return v % 2 == 0
end) -- or my_writable_store:filter(fn)
my_filtered_store:subscribe(function(v) print(v); end) -- prints "nil"
for i = 2, 10 do my_writable_store:set(i) end -- prints "2", "4", "6", "8", "10"
The final, and arguably most exciting type of store is tweened
. It allows you
to smoothly translate between one value and another asynchronously.
The tweened function takes between one and two values, with the first being the initial value, anhd the second being a table of options to control how the store behaves.
local awestore = require "awestore"
local my_tweened = awestore.tweened(0, {
duration = 100,
easing = awestore.easing.back_in_out,
})
my_tweened:subscribe(function(v) print(v); end) -- prints "1"
my_tweened:set(1) -- prints "-0.027..."
-- prints "-0.076..."
-- prints "-0.099..."
-- prints "-0.051..."
-- prints " 0.113..."
-- prints " 0.441..."
-- prints " 0.817..."
-- prints " 1.020..."
-- prints " 1.095..."
-- prints " 1.087..."
-- prints " 1.041..."
-- prints " 1.003..."
-- prints " 1"