LÖVE

Code: Select all

local mt_class = {}

function mt_class:extends(parrent)
	self.super = parrent
	setmetatable(mt_class, {__index = parrent})
	parrent.__members__ = parrent.__members__ or {}
	return self
end

local function define(class, members)
	class.__members__ = class.__members__ or {}
	for k, v in pairs(members) do
		class.__members__[k] = v
	end
	function class:new(...)
		local newvalue = {}
		for k, v in pairs(class.__members__) do
			newvalue[k] = v
		end
		setmetatable(newvalue, {__index = class})
		if newvalue.__init then
			newvalue:__init(...)
		end
		return newvalue
	end
end

function class(name)
    local newclass = {}
	_G[name] = newclass
	return setmetatable(newclass, {__index = mt_class, __call = define})
end

Code: Select all

--creates a class with 2 data members
class "Shape" {
	width = 0;
	height = 0;
}
--creates a constructor
function Shape:__init(a, b)
	self.width = a
	self.height = b
end
--creates a function that dose nothing useful,
function Shape:talk()
	print("shapes can talk?")
end

--creates a class called rectanlge that inherts from Shape
class "Rectangle" : extends(Shape) {}

--constructor has already been inhierted, no need to make it
--overloads Shape:talk
function Rectangle:talk()
	print("im a rectangle!!")
end
--new function to show how a sub-class can call it's parrents methods even if they have been overloaded
--if you need to call the parrent of a parrents method you can do self.super.super.method(self) and so on untill you have gone back sufficently far
function Rectangle:supertalk()
	self.super.talk(self)
end
--create an area function that tells us the area of a rectangle
function Rectangle:area()
	return self.width * self.height
end

--creates another class that inherits from shape, this time representing a triangle
class "Triangle" : extends(Shape) {}

function Triangle:area()
	return self.width * self.height / 2 
end

local rect = Rectangle:new(10, 10)
local tri = Triangle:new(10, 10)

print(rect:area())
print(tri:area())
print(rect:talk())
print(rect:supertalk())