workspaces vs libraries and runtime.path

[dkuettel]

Hello,

I'm trying to confirm my understanding here. Originally and naively, I thought workspace folders are used to point the LS at different locations for lua files in a project, and that libraries are meant to point at external stuff that you dont plan to change.

But from reading in different places, and also from #1567 (comment) it seems like workspace folders are completely separate. I read the lsp specifications and maybe this is the intention, I can't say for sure. If so, what is the use of that? Seems to me then you would have just started two different language servers, since they act isolated anyway. Is this about efficiency?

Be that as it may: Do you have an idea how to setup the lua LS so that it includes files from different places in my project? Not just, from, eg, lua/*? If I change runtime.path it would also apply to libraries, and that's not okay. Or should I point libraries at paths inside the project?

Cheers, Daniel.

[tomlau10]

it seems like workspace folders are completely separate
... Is this about efficiency?

Yes, you're referring to the Multiple Workspace Support feature:
https://luals.github.io/wiki/developing/#multiple-workspace-support

This setup shares files/libraries across workspaces to reduce memory usage.
For example, if both workspaces use Lua 5.4, the built-in library files are loaded into memory once.

A common use case is a client/ & server/ setup within one repo that shares files in a shared/ folder.
You can create a multi-root workspace with separate .luarc configs, both including "workspace.library": "../shared".
See this example: #3030 (comment)

Do you have an idea how to setup the lua LS so that it includes files from different places in my project?
... If I change runtime.path it would also apply to libraries, and that's not okay.

This depends on your project structure 🤔

Since separate workspaces have separate environments, if you want a single environment, include files from different locations using workspace.library in your main project's config.
The runtime.path setting only affects how LuaLS searches module paths for require "some.module".

You can add multiple patterns to runtime.path:

• Your workspace files: lua/*
• Library files: /external/path/src/*
• Set runtime.path: ["lua/?.lua", "src/?.lua"]
• require "some.module" will then search both ./lua/some/module.lua and /external/path/src/some/module.lua

This allows LuaLS to find modules in both locations.
Note that you should better avoid same-named modules to prevent ambiguity. 😂

Or should I point libraries at paths inside the project?

If your library files are within the same root workspace (just in different subfolders), you don't need workspace.library.
LuaLS preloads all Lua files in your workspace automatically (unless excluded by workspace.ignoreDir).
Simply adjust runtime.path so require "some.module" correctly locates files in different subfolders under your workspace root.

---

Can you share more details about your workspace structure?

[dkuettel]

Thanks for the clear explanations, much appreciated! That helps a lot, I did have some misconceptions about it then.

A minimal example of my setup is like this (for nvim): There is a ./config/lua and a ./plugins/layouts/lua, both of them with the usual ["?.lua", "?/init.lua"], but different workspace.library. Both ./config/lua and ./plugins/layouts/lua have a .luarc.json. When I do plain two separate lsps, all works fine. (The lsp for ./config/lua has ./plugins/layouts/lua referenced as a library.)

But when I try it with workspaces, after your explanations above, I use one lsp and set workspace_folders to ./config/lua and ./plugins/layouts/lua. I use --loglevel info and when I look at the log I see it only ever loads one .luarc.json, the one from ./config/lua. That is after opening a file from both workspaces.

Are the configs supposed to be loaded from those 2 different .luarc.jsons? Or does the lsp in this case ask the client for the settings for both workspace folders? Maybe then the problem is still on my nvim config side? I can clearly tell when I open a file in ./plugins/layouts/lua that it uses the environment of ./config/lua.

[tomlau10]

I'm not familiar with neovim (I use vscode).

In vscode's multi-root workspace, the vscode-lua extension sends workspaceFolders[] to the server, which then runs in multi-workspace mode and loads config files from each workspace.

lua-language-server/script/provider/provider.lua

Lines 111 to 123 in 24b9faa

	m.register 'initialize' {
	function(params)
	client.init(params)
	if params.rootUri then
	workspace.initRoot(params.rootUri)
	cap.resolve('ROOT_PATH', furi.decode(params.rootUri):gsub('\\', '/') .. '/')
	end
	if params.workspaceFolders then
	for _, folder in ipairs(params.workspaceFolders) do
	workspace.create(files.getRealUri(folder.uri), folder.name)
	end

The lsp for ./config/lua has ./plugins/layouts/lua referenced as a library.

I'm not sure I understand this setup. 😕

Do you mean you set both ./config/lua and ./plugins/layouts/lua as workspace roots (multi-root workspace mode), but also reference ./plugins/layouts/lua as a library in ./config/lua's .luarc.json?

This might confuse the server 😂 When you open a file under ./plugins/layouts/lua, the server may not know which workspace this file belongs to.

[dkuettel]

Hm are you sure? Workspaces are isolated environments. If ./config/lua uses ./plugins/layouts/lua (but not the other way around), don't I have to add it somehow to make it known? I can see that it might not know which workspace it belongs to, true, but this kind of dependencies are realistic, right? With two separate LSPs right now it works fine though, because nvim will decide to give an opened file to the correct LSP based on the root folder.

In the link you provided (#3030 (comment)) there also is a shared library between client and server, but that one is not part of any workspace, so I guess it's a bit different.

[tomlau10]

I'm actually quite confused now 😕

• AFAIK, a single workspace in LuaLS represents a single Lua runtime environment
  It emulates one Lua instance that includes/requires all your files and libraries.

• The multi-root workspace feature is for opening multiple separate runtime environments within the same editor session.
  Like in my provided link example: client and server
  They are two independent environments of the same project.
  And I want both open in the same vsocde session. (instead of 2 vscode instances)

---

Now in your case, you say ./config/lua uses ./plugins/layouts/lua.
Doesn't this mean that in the Lua runtime of ./config/lua, any files it requires from ./plugins/layouts/lua should share the same Lua environment? 😕

And if ./plugins/layouts/lua is just a standalone library path, why do you want to open it using multi-root workspace alongside ./config/lua?

don't I have to add it somehow to make it known?

I believe you only need to add ./plugins/layouts/lua as a worksapce.library path in the ./config/lua project, but you don't have to include ./plugins/layouts/lua using a mulit-root workspace setup.
(worksapce.library is meant for adding paths that are outside of current workspace already)

PS: a bit googling found out that these 2 paths are common neovim configuration directories
Since I am not familiar with neovim, I may not be able to help you further 🙈