在Lua中，有没有一种方法可以找出值所在的表？

Question

例：

player = {}
player.shape = {x = 0, y = 0, w = 50, h = 50}

Lua中是否有一个函数可以告诉我表player.shape所在的位置，所以我可以执行以下操作：

shape_a = player.shape
some_function(shape_a) = player

Answer 1

为什么不只在形状中存储对父表的引用？

player = {}
player.shape = {x = 0, y = 0, w = 50, h = 50, parent = player}

您可以使用以下元方法自动执行此操作：

local new_player = function()
  return setmetatable(
    {},
    {
      __newindex = function(t,k,v)
        if k == "shape" then v.parent = t end
        rawset(t,k,v)
      end,
    }
  )
end

player = new_player()
player.shape = {x = 0, y = 0, w = 50, h = 50}

现在，您可以通过调用从形状访问播放器shape.parent。