Pattern.js ported to Lua

Pattern.lua

Pattern = {}

function Pattern:extend(obj)
  local child = obj or {}
  setmetatable(child, {__index = self})
  return child
end

function Pattern:new(...)
  local obj = {}
  setmetatable(obj, {__index = self})
  if not self.initialize then
    return obj
  end
  
  obj:initialize(unpack({...}))
  
  return obj
end
  
Rectangle = Pattern:extend()

function Rectangle:initialize(width, height)
  self.width = width
  self.height = height
end

function Rectangle:getArea()
  return self.width * self.height
end

local rect = Rectangle:new(10, 20)
print("rect " .. tostring(rect))
print("rect:getArea() " .. rect:getArea())

local MagicRectangle = Rectangle:extend()

function MagicRectangle:getArea()
  return self.width * self.height * 100
end

local rect2 = MagicRectangle:new(10, 20)
print("rect2 " .. tostring(rect2))
print("rect2:getArea() " .. rect2:getArea())