snug.lua

local stack_prototype = { __index = {
  MAXSIZE = 100,  -- default max size (client called newstack() with no size)
  
  push = function(self,val)
    if #self > self.MAXSIZE then
      table.remove(self,1)
    end
    self[#self+1] = val
  end,
  
  pop = function(self)
    return table.remove(self)
  end,
} }

function newstack(MAXSIZE)
  return setmetatable({ MAXSIZE = MAXSIZE },stack_prototype)
end