Lua operator overloading

v2.lua

-- Helpers
function v2_add() 
  -- foo..
end

-- Vector
local vector = {}
local vector_meta = {}

function vector:new(x, y)
  local _ = {x=x or 0,y=y or 0}
  return setmetatable(_, vector_meta)
end

vector_meta.__add = function(a, b) return v2_add(a,b, vector:new(a,b)) end
  
-- more:
-- vector_meta.__sub
-- vector_meta.__tostring
-- etc...

local vectorPlayer = vector:new(10,10)
local vectorEnemy = vector:new(2,2)
local added = vectorPlayer + vectorEnemy