32logex

[Centauri Soldier]

I decided to modify the wondeful 32 Lines of Goodness to suit my own project and it turned out to be pretty useful for more than that one project. So, I thought I'd share it here for anyone else who might need such functionality. I know, it's not 32 lines anymore. I left that in the name to honor the original author.

32LoGEx now allows for all metamethods for your custom class.
32LoGEx now creates a pseudo-type for your custom class which can be returned by the lua type() function.

Code: Select all

--[[
This is a modification of the '32 Lines of Goodness' found at https://love2d.org/wiki/32_lines_of_goodness.

Added Features:
	Allows the creation of all known metamethods for each class.
		E.g.,
		class "MyClass" {};
		function MyClass:__tostring() return "This is what I want to return." end
		local obj = MyClass:new();		
		print(tostring(obj));
		-> Output would be "This is what I want to return."
	Creates pseudo-types of each class created by overriding the lua type() function.
		E.g.:
		class "CoolClass" {};
		local obj = CoolClass:new();
		print(type(obj));		
		-> output would be "CoolClass"
		

Copyright © 2019 AMSPublic.org

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
]]

local mt_class = {}
 
function mt_class:extends(parent)
	self.super = parent
	setmetatable(mt_class, {__index = parent})
	parent.__members__ = parent.__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,
							__add = 		class.__add,
							__concat =		class.__concat,
							__div =			class.__div,
							__eq =			class.__eq,
							__le =			class.__le,
							__len =			class.__len,
							__lt =			class.__lt,
							__mod =			class.__mod,
							__mul =			class.__mul,
							__newindex = 	class.__newindex,
							__pow =			class.__pow,
							__sub =			class.__sub,
							__tostring = 	class.__tostring,
							__type =		class.__type,
							__unm =			class.__unm,
							
						}
					);
	  
		if newvalue.__init then
			newvalue:__init(...);
		end
	  
		return newvalue;
	end
	
end

function class(name)
	local newclass = {
		__add = 		function() end,
		__concat = 		function() end,
		__div = 		function() end,
		__eq = 			function() end,
		__le = 			function() end,
		__len = 		function() end,		
		__lt = 			function() end,
		__mod = 		function() end,
		__mul = 		function() end,
		__newindex = 	function() end,
		__pow = 		function() end,
		__sub = 		function() end,
		__tostring = 	function() end,
		__type =		name,
		__unm = 		function() end,		
	};
	
	_G[name] = newclass;
   
	return setmetatable(newclass, {__index = mt_class, __call = define});
end

local _type = type;
function type(vObj)
	local sType = _type(vObj);
	
	if (sType == "table") then
	
		local tMeta = getmetatable(vObj);
		
		if (tMeta) then
		
			if (tMeta["__type"]) then
				sType = tMeta["__type"];
			end
			
		end
		
	end

	return sType;
end