enum.lua

local enummt = {
  __index = function(table, key) 
    if rawget(table.enums, key) then 
      return key
    end
  end
}

local function Enum(t)
  local e = { enums = t }
  return setmetatable(e, enummt)
end

local Screen = Enum {
  Title = 1,
  CharacterSelect = 1,
  Playing = 1,
  Paused = true,
  Won = "anyTruthy",
  Lost = 1
}

print(Screen.Title == Screen.Playing, Screen.Cat)
-- despite having the same value they're not equivalent