Added code to export definitions for a lua-language-server

[NiLSPACE]

I still need to write an article to explain how to configure the language server so this PR is still a work in progress, but the definition generation seems to be working now.

The definitions should work with any IDE that can use lua-language-server. Here is an example with Visual Studio Code:

2023-03-12.14-40-15.mp4

[NiLSPACE]

I now see why everything in the APIDump plugin was in a single file ;) It's so the functions don't show up in the global environment. I'll move the functions over to the main file later.

[madmaxoft]

Seeing the APIDump code makes me want to rewrite it :)

[NiLSPACE]

I had the same urge when I looked at some (or most) of the WorldEdit code yesterday ;)

[NiLSPACE]

The 'not polluting _G' issue could also be fixed by immediately replacing _G with an empty table with __index pointing to the old values.

local newEnv, oldEnv = {}, _G
local setmetatable = setmetatable
for k, v in pairs(_G) do
	newEnv[k] = v;
	oldEnv[k] = nil;
end
_G = setmetatable(oldEnv, {__index = newEnv});

Then instead of looping through _G you'd loop through getmetatable(_G).__index

[madmaxoft]

So is it VSCode-only or generic lua-language-server? Just to get the naming right.

[NiLSPACE]

I've only tested it on VSCode, but it should work on any lua-language-server. But you're right, I'll change the naming.

[madmaxoft]

Will this comparison still work? I doubt that.

[NiLSPACE]

It actually does still work.

The _preload code doesn't replace the actual _G table. It just takes its values and moves it to a new table. So once it gets to the _G key it takes the reference to itself and moves it to the new table.

Put in another way: Usually _G references to itself like this:

_G._G._G._G...

but with _preload this changes to

_G.__index._G.__index...
  ▲
   because of getmetatable() we start here which means its _G value 
   references back to the global _G environment