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

Inizia con il comportamento di in Lua 5.4 e la riproduzione fornita di get_resource. Determina come il server del linguaggio rappresenta annotazioni e avvisi, quindi definisci un modo per identificare le risorse con __close che vengono assegnate senza ; il lavoro è completato quando l’esempio segnala un avviso per b e accetta a.