jspower.lua

JavaScript-style Array, String and Math, in Lua!

jspower.lua implements Array, String, Math, Number from JavaScript, giving you all the power from JavaScript while staying in Lua!

License

Copyright (c) 2021 Miigon, open-sourced under the MIT License

Examples

tested under Lua 5.1 and LuaJIT 2.1.0-beta3

Array

local Array = require("./jspower.lua").Array

-- Notice that indecies in Lua start from 1, not 0. 

local a = Array.new({1, 2, 3, 4, 5})
print(a) -- 1,2,3,4,5

print(a:pop()) -- 5
print(a:pop()) -- 4
print(a) -- 1,2,3

print(a:push(666)) -- 4 (new length of the array)
print(a) -- 1,2,3,666

print(a:reverse()) -- 666,3,2,1

print(a:unshift(777)) -- 5 (new length of the array)
print(a:shift()) -- 777
print(a:shift()) -- 666
print(a) -- 3,2,1

local a = Array.new({1, 2, 3, 4, 5, 6, 7, 8})
print(a) -- 1,2,3,4,5,6,7,8

print(a:slice(4,7)) -- 4,5,6
print(a) -- 1,2,3,4,5,6,7,8

print(a:splice(4,3)) -- 4,5,6
print(a) -- 1,2,3,7,8

print(a:reduce(function(acc, val) return acc + val end)) -- 21

local a = Array.new({"banana", "cat", "apple"})
print(a:sort()) -- apple,banana,cat

print(a:includes("banana")) -- true
print(a:includes("coconut")) -- false
print(a:indexOf("banana")) -- 2
print(a:indexOf("coconut")) -- -1

local a = Array.new({1, 2, 3, 4, 5, 6, 7, 8})
print(a:filter(function(v, i) return i % 2 == 0 end)) -- 2,4,6,8

-- and many more...

String

local jsp = require("./jspower.lua")
local String = jsp.String


print(String.fromCharCode(97)) -- a
print(String.charCodeAt("hello, world!",8)) -- 119
print(String.charAt("hello, world!",8)) -- w
print(String.concat("hello,", " lua!")) -- hello, lua!
print(String.startsWith("banana", "ba")) -- true
print(String.endsWith("coconut", "nut")) -- true
print(String.includes("javascript", "vasc")) -- true

-- Alternatively, use jsp.extendLuaString()
jsp.extendLuaString()
-- After this, you can do:

print(("hello, world!"):charAt(8)) -- w
print(("hello,"):concat(" lua!")) -- hello, lua!
print(("banana"):startsWith("ba")) -- true
print(("coconut"):endsWith("nut")) -- true
print(("javascript"):includes("vasc")) -- true

local str = "     trim me daddy  "
print(str:trim()) -- "trim me daddy"
print(str:trimEnd()) -- "     trim me daddy"
print(str:trimStart()) -- "trim me daddy  "

local str = "Use the power of JS in Lua"
print(str:split(" ")) -- { "Use", "the", "power", "of", "JS", "in", "Lua" }
print(str:split("JS")) -- { "Use the power of ", " in Lua" }
print(str:toUpperCase()) -- USE THE POWER OF JS IN LUA
print(str:toLowerCase()) -- use the power of js in lua

Number

local jsp = require("./jspower.lua")
local Number = jsp.Number

print(Number.parseInt("13A6")) -- 13
print(Number.parseInt("13A6",16)) -- 5030
print(Number.toFixed(13.44511, 2)) -- 13.45
print(Number.toPrecision(13.44511, 3)) -- 13.4
print(Number.isNaN(11111)) -- false
print(Number.isNaN(Number.NaN)) -- true
print(Number.isFinite(jsp.Infinity)) -- false
print(Number.isFinite(3.33333)) -- true

Disclaimer

This project is not thoroughly tested against each and every edge-cases, and may not produce consistent result with a real JavaScript engine.

However, if you did find any such inconsistency, please report by opening an issue! Any contribution is appreciated!

Unsupported Features

RegEx, locale, UTF-16 related (due to lack of native support) functionalities