Creating a Lua dialect

[Keyslam]

Hey 👋

I'd like to create a simple Lua dialect for personal use called Lila, which adds features such as += operators, continue statements, preprocessor directives, and a bit more. My goal is for Lila to be fully compatible with the Sumneko language server; I just want to enhance the standard Lua experience.

I already have this kind of working with the plugin system: I've made a custom ANTLR grammar, and in the plugin's OnSetText use ANTLR to parse the .lila files, walk the tree, figure out the positions of any of my custom tokens, and create a table of diffs. Besides maybe some syntax highlighting issues, this works totally fine.

The problem comes when I want Lila to work with multiple files, which means requiring needs to happen, so it needs to transpile files on the fly and save them somewhere, even if the file is not currently being edited, but this causes the following:

src/
  a.lila (Currently open)
  b.lila
build/
  a.lua (Transpiled from src/a.lila)
  b.lua (Transpiled from src/b.lila)
LOGPATH/
  diffed.lua (Diffed from src/a.lila)

Now diffed.lua will be have the same contents as a.lua, which will cause the language server to complain: There are now duplicate definitions.
I can't exclude the files from build, because the transpiled b.lua might be require'd by a.lua, and the @package annotation only works with .lua files.

Is there some way to circumvent this?

[Keyslam]

For me the ideal solution would be to, instead of the plugin returing a table of diffs, returning another URI which acts as the open file's contents. I have no idea if this is possible and/or wanted. I have some (pseudo)code to explain what I mean:

function OnSetText(uri, text)
    local extension = uri:match("^.+(%..+)$")
    if (extension ~= ".lila") then
        return nil
    end

    local newFileContents = Transpile(text)
    local newFileUri = uri .. ".lua"
    WriteFile(newFileContents, newFileUri)

    return newFileUri
end

Which would result in

src/
  a.lila (Currently open)
  a.lila.lua (Considered currently open)
  b.lila
  b.lila.lua