32log.lua

--[[
-- 32 lines of goodness.
-- Links to original source of code and usage documentation:
-- http://love2d.org/wiki/32_lines_of_goodness
-- http://love2d.org/forums/viewtopic.php?f=5&t=3344
-- Patches by Robin and FSX (which bring it to 41 lines)
--]]
local mt_class = {__index = mt_class, __call = define}

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

local function define(class, members)
	class.__members__ = class.__members__ or {}
	local function copyMembersDown(origin, cls)
		if cls.super then
			for k, v in pairs(cls.super.__members__) do
				origin[k] = v
			end
			return copyMembersDown(origin, cls.super)
		end
	end
	copyMembersDown(class.__members__, class)
	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, mt_class)
end