Feature for Lua 5.4 to warn about unused __close metamethods.

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

MacOS

What is the issue affecting?

Annotations

Expected Behaviour

I think it would make sense to be able to somehow annotate that a table with a __close metamethod is meant to be used as a local variable with lua 5.4's attribute. This would be useful for raii-like constructs.

Actual Behaviour

No warning.

Reproduction steps

Example:

local function get_resource()
  return 
    setmetatable({}, {
        __close = function ()
          print('close resource')
        end
    })
end


local a<close> = get_resource() -- ok

local b = get_resource() -- not okay, should somehow warn

Additional Notes

No response

Log File

No response

从 Lua 5.4 的 行为和提供的 get_resource 复现开始。确定语言服务器如何表示注解和警告，然后定义一种识别带有 __close 但在没有 的情况下被赋值的资源的方法；完成标准是示例对 b 发出警告，同时接受 a。