Is there a way to declare table.deepcopy() as builtin somehow?

[QuingKhaos]

I know, normally there is no table.deepcopy(), but in Factorio modding, this is provided by the engine. Is there a way to mark that as builtin without annotating each line to disable diagnostics on it?

I want to prevent to write this every time:

---@diagnostic disable-next-line: undefined-field
local icon_copy = table.deepcopy(icon_layer)

[carsakiller]

There are various ways this can be done.

You can simply add a file in your workspace, say, under types/ and add the following:

---@meta

---@generic T: table
---@param t T
---@return T
table.deepcopy = function(t) end

Using generics allows more detailed information retrieved from the given table to persist in the returned value. A simpler version, if generics aren't working for you, is just the following:

---@meta

---@param t table
---@return table
table.deepcopy = function(t) end

So long as that file is included in diagnostics and is not being excluded via your settings, that should do it.

A cleaner solution would be to put that file somewhere outside your project, and then point to it using workspace.library.

There is also likely a more complete solution someone has made out there that provides all the types for Factorio already. I found an addon someone has already made for Factorio on GitHub.

I recommend checking out the LuaLS wiki to learn more about addons, annotations, settings, and more.